Dietary biology of the Eurasian eagle-owl
In the Iberian peninsula, the Eurasian eagle-owl is part of a complex guild of predators that have evolved to survive mostly on European rabbits. Among this guild, golden eagles (Aquila chrysaetos) were recorded per one study to rely on rabbits for 40% of the diet, the eagle-owl for 49% of the diet, the Spanish imperial eagle (Aquila adalberti) for 50% of the diet, the Bonelli's eagle (Aquila fasciata) for 61% of the diet and the Iberian lynx (Lynx pardinus) for 79% of the diet.[2] Elsewhere, the Spanish imperial eagle and eagle-owl are considered to outflank the golden and even the Bonelli's eagle as the most specialized avian predator of rabbits in the Iberian region.[13] Other predators, such as common buzzard (Buteo buteo), northern goshawk (Accipiter gentilis) black kite (Milvus migrans) Iberian wildcat (Felis silvestris tartessia), red fox, stone marten (Martes foina) and introduced Egyptian mongoose also prey heavily on rabbits in Spain, but are more generalized and less reliant than the above predators.[117][118][119][120] All these powerful predators do not generally compete directly for food but conflicts may ensue over the rights to territories and nesting sites amongst the birds. Being nocturnal in activity, however, the Eurasian eagle-owl does not tend to compete as directly as do the three eagle species and even these are discreetly segregated by habitat preferences, the goldens preferring open, steep cliffs, the Bonelli's favoring densely vegetated areas mixed with rocky spots and the imperial favoring relatively flat open woodlands.[121] Among these eagles, the golden eagle tends to have the most similar habitat preferences to the Eurasian eagle-owl and across a broad band of overlapping distribution, the two are considered nearly ecological equivalents by day and night. However, good-sized female golden eagles are up to twice as heavy as an average eagle-owl, so seem to have a considerable advantage in size and power.[2] Conversely, to support their large size and large territory needs, the golden eagle cannot survive on small and diverse prey nearly as successfully as the eagle-owl. Among the Iberian peninsula rabbit-eating guild, the species with wider ranges, the eagle-owl and the golden and Bonelli's eagles, have had some degree of success living off of alternate prey following the devastation of the rabbit population due to rabbit haemorrhagic disease. The two rabbit predators endemic to Iberia, the Iberian lynx and Spanish imperial eagle, have been devastated by the reduction and other causes and both are threatened species today.[122][123][124][125]
Verreaux's eagle-owl
On average, sexual maturity in Verreaux's eagle-owls appears to be attained at three to four years of age. In most cases, a pair of Verreaux's eagle-owl is able to nest annually, however in some cases they may nest only every two to three years, in probable situations of extreme food shortages. Annual mortality appears to be fairly low in this large owl species. Few species have been reported to hunt Verreaux's eagle-owls short of the aforementioned jackal attack, even nests have rarely been seen to be predated, although they may on rare occasions run afoul of some predators such as larger felids with the ability to climb, although such cases are as yet unverified. That young birds usually leave the nest before they can fly would appear to endanger them but the threat and distraction display of parent eagle-owls are apparently often successful. Adult eagle-owls can appear nearly fearless, as they have been reported to stand their ground and engage in threat displays when encountered on or near the ground against much larger animals such as rhinoceroses and lions and in such cases are apparently not approached further by the bigger animals although the eagle-owls could easily be killed by such animals if contact was made. The lifespan in the wild is not known to have been researched, however in captivity the species can live for over 15 years, possibly up to 30 years in some cases. Eurasian eagle-owl
The fourth and most famous derivation of the evolutionary line that includes the Eurasian eagle-owl is the great horned owl, which appears to have been the result of primitive eagle-owls spreading into North America.[6] It has been stated that the great horned owls and Eurasian eagle-owls are barely distinct as species, with a similar level of divergence in their plumages as the Eurasian and North American representations of the great grey owl or the long-eared owl.[6] There are more outward physical differences between the great horned owl and the Eurasian eagle-owl than in those two examples, including a great size difference favoring the Eurasian species, the great horned owl’s horizontal rather than vertical underside barring, yellow rather than orange eyes and a much strong black bracket to the facial disc, not to mention a number of differences in their reproductive behaviour and distinctive voices.[14] Furthermore, genetic research has revealed that the snowy owl is more closely related to the great horned owl than are Eurasian eagle-owls.[14] The most closely related species beyond the Pharaoh, Indian and Cape eagle-owls to the Eurasian eagle-owl is the smaller, less powerful and African spotted eagle-owl (B. africanus), which was likely to have divided from the line before they radiated away from Africa. Somehow, genetic materials indicate the spotted eagle-owl appears to share a more recent ancestor with the Indian eagle-owl than with the Eurasian eagle-owl or even the sympatric Cape eagle-owl.[14] Eurasian eagle-owls in captivity have produced apparently healthy hybrids with both the Indian eagle-owl and the great horned owl.[4][6] The Pharaoh, Indian and Cape eagle-owls and the great horned owl are all broadly similar in size to each other, but all are considerably smaller than the Eurasian eagle-owl, which averages at least 15–30% larger in linear dimensions and 30–50% larger in body mass than these other related species, possibly as the eagle-owls adapted to warmer climates and smaller prey. Fossils from south France have indicated that during the Middle Pleistocene, Eurasian eagle-owls (this paleosubspecies given the name B. b. davidi) were larger than they are today, even larger were those found in Azerbaijan and in Caucasus (either B. b. bignadensis or B. bignadensis), which were deemed to date to the Late Pleistocene.[6] About a dozen subspecies are recognized today.[2] European badger
European badgers have few natural enemies. Grey wolves ("Canis lupus"), Eurasian lynxes ("Lynx lynx") and brown bears ("Ursus arctos"), Europe's three largest remaining land predators, and large domestic dogs ("C. l. familiaris") can pose a threat to adult badgers, though deaths caused by them are quantitatively rare as these predators are often limited in population due to human persecution and usually prefer easier, larger prey like ungulates, while badgers may fight viciously if aware of a predator and cornered without an escape route. They may live alongside red foxes ("Vulpes vulpes") in isolated sections of large burrows. The two species possibly tolerate each other out of commensalism; foxes provide badgers with food scraps, while badgers maintain the shared burrow's cleanliness. However, cases are known of badgers driving vixens from their dens and destroying their litters without eating them. In turn, very large male red foxes are known to have killed badgers in spring. Golden eagles ("Aquila chrysaetos") are known predators of European badgers and attacks by them on badger cubs are not infrequent, including cases where they've been pulled out directly from below the legs of their mothers, and even adult badgers may be attacked by this eagle when emerging weak and hungry from hibernation. Eurasian eagle owls ("Bubo bubo") may also take an occasional cub and other large raptors such as white-tailed eagles ("Haliaeetus albicilla") and greater spotted eagle ("Clanga clanga") are considered potential badger cub predators. Raccoon dogs may extensively use badger setts for shelter. There are many known cases of badgers and raccoon dogs wintering in the same hole, possibly because badgers enter hibernation two weeks earlier than the latter, and leave two weeks later. In exceptional cases, badger and raccoon dog cubs may coexist in the same burrow. Badgers may drive out or kill raccoon dogs if they overstay their welcome. Dietary biology of the Eurasian eagle-owl
The Eurasian eagle-owl may hunt at least 300 species of bird. In Europe, the most common avian prey species are the normally feral or domestic 355g (12.5oz) rock pigeons (Columba livia), although the 490g (17oz) common wood pigeon (Columba palumbus) can be locally even more significant. In the Netherlands, the common wood pigeon is the most important prey species, making up 37.3% by number and 38.3% by biomass. Yet another, smaller study of the Netherlands found the rock pigeon to be the primary prey species.[58][95] In a dietary study from Luxembourg, the common wood pigeon was the most frequent prey species, making 19% of the remains by number.[96] A study from Romania listed the rock pigeon was the second most frequently recorded prey behind only the Romanian hamster and the largest contributed of biomass.[43] Unusually, in the Netherlands, birds were the primary food in both number (77.6%) and biomass (72%).[58] Also, in Luxembourg, eagle-owls hunted birds in general were more regularly than mammals, as nearly 70% of prey remains there were avian.[96] At least six other species of pigeon and dove have also been recorded as prey. However, perhaps the most significant contributor of prey at the family level is the corvids and all available species have been targeted. The 570g (1.26lb) carrion crow (Corvus corone) is the second most widely recorded avian prey species in Europe and, locally, good numbers are also taken of 490g (1.08lb) hooded crow (Corvus cornix), 245g (8.6oz) western jackdaws (Corvus monedula), 160g (5.6oz) Eurasian jays (Garrulus glandarius), 1,085g (2.392lb) common ravens (Corvus corax), 455g (1.003lb) rooks (Corvus corone), two species each of magpie and chough and the 183g (6.5oz) spotted nutcracker (Nucifraga caryocatactes), in rough descending order of reportage in the eagle-owl's diet.[33][58][72][74][76][95] In Baden-Württemberg, Germany, the carrion crow was the most frequently recorded bird among an exceptionally diverse recorded prey base including than 65 bird species there (although birds only comprised 27% of the prey numbers overall).[97] Unlike smaller passerines, corvids roost in numbers in relatively open spots, which make them fairly vulnerable to a predator as stealthy and powerful as the eagle-owl.[98] More than 17 species of gamebirds have been recorded in the Eurasian eagle-owl's diet but they are normally taken in small numbers. There are, however, exceptions. In one study conducted in lower Austria, the most frequently identified prey species was the 405g (14.3oz) grey partridge (Perdix perdix), which is the most widely reported gamebird prey for eagle-owls in Europe.[18][99] One study of a “primeval” forested region of Finland found various grouse species to be the most significant contributor of biomass, namely in descending order the 2,950g (6.50lb) western capercaillie (Tetrao urogallus), the 1,080g (2.38lb) black grouse (Tetrao tetrix) and the 429g (15.1oz) hazel grouse (Bonasa bonasia).[2][95] In inland areas of Norway, the large forest grouse were also significant biomass contributors.[14] The same forest grouse species were also found to be significant to diet along the Pechora River in Russia.[18] Other gamebirds can be important secondary prey species in different parts of Europe: the 528g (1.164lb) red-legged partridge (Alectoris rufa) in western Europe, the 615g (1.356lb) rock partridge (Alectoris graeca) and the 535g (1.179lb) rock ptarmigan (Lagopus mutus) in alpine highlands, the 1,135g (2.502lb) ring-necked pheasant (Phasianus colchicus) in eastern Europe and the 570g (1.26lb) willow ptarmigan (Lagopus lagopus) in the sub-Arctic zone.[39][41][95][100] In Turkey, the most significant prey by number was the 503g (1.109lb) chukar (Alectoris chukar), comprising 20.5% of remains.[12] A Korean study in two habitat types (forest and field) found that ring-necked pheasants were the main prey species, making up an average of 19.33% by number and 34.81% by biomass.[101] Other birds of prey are perhaps second only to pigeons and corvids amongst avian contributors to the diet (their ecological relationships with eagle-owls are explored in more detail below).[2] Red fox
In Eurasia, red foxes may be preyed upon by leopards, caracals and Eurasian lynxes. The lynxes chase red foxes into deep snow, where their longer legs and larger paws give them an advantage over foxes, especially when the depth of the snow exceeds one metre. In the Velikoluki district in Russia, red foxes are absent or are seen only occasionally where lynxes establish permanent territories. Researchers consider lynxes to represent considerably less danger to red foxes than wolves do. North American felid predators of red foxes include cougars, Canadian lynxes and bobcats. Occasionally, large raptors such as Eurasian eagle owls will prey on young foxes, while golden eagles have been known to kill adults. Dietary biology of the Eurasian eagle-owl
Larger and more dangerous mammalian prey is not infrequently tackled by Eurasian eagle-owl. Nearly thirty species of mammalian carnivores have been reported in their diet.[2] Many of these are mustelids, which are the smallest type of carnivore but can defend themselves viciously, even the tiny 67g (2.4oz) least weasel (Mustela nivalis).[79] Nonetheless, unlike some smaller birds of prey, the Eurasian eagle-owl seems to have no problem subduing various weasels and even martens, some of the latter can nearly equal to their own weight, and will kill the young of much larger species such as European otter (Lutra lutra) and Eurasian badger (Meles meles).[80][81][82] However, the single most widely reported carnivore is the red fox (Vulpes vulpes), as they've been recorded in the diet from Denmark and Spain to the Russian Far East.[20][72][83] Many fox specimens taken by eagle-owls are young individuals or subadults. Some studies posited that the average fox taken as weighing about 2,500 to 3,000g (5.5 to 6.6lb), about equal to the eagle-owl's own weight, but another noted fox specimens killed that were estimated to weigh 8,000g (18lb), much larger than the eagle-owls.[20][57][58][66] At least four other species of foxes have been verified as prey in the Middle East and Asia.[2][51][84][85] Raccoon dogs (Nyctereutes procyonoides), averaging 6,500g (14.3lb), have been preyed on in Asia as well.[86] Other relatively large carnivores have been hunted as well, including invasive Egyptian mongoose (Herpestes ichneumon) in Spain and masked palm civets (Paguma larvata) in China, both being roughly cat-sized at averages of 2,300 and 4,300g (5.1 and 9.5lb), respectively.[2][25][87] Domestic carnivores including cats (Felis silvestris catus) of all sizes and small dogs (Canis lupus familiaris) or puppies may on occasion become prey for Eurasian eagle-owls. Cats killed have been estimated to weigh from 3,200 to 7,500g (7.1 to 16.5lb).[20][37][66][87] The dogs killed by Bavarian eagle-owls were estimated to average 4,000g (8.8lb).[66] Non-native carnivores such as American mink (Neovison vison) and raccoon (Procyon lotor) have also been preyed on by eagle-owls, which is presumed to incidentally benefit the prey taken in considerably numbers by these rarely checked invasive fur-bearers.[88][89] Dietary biology of the Eurasian eagle-owl
The Eurasian eagle-owl is perhaps the only living owl widely reported (if not commonly) to kill the young of ungulates. At least nine species have been identified as their food. It is possible that some ungulates are eaten as carrion but this species, like most owls, normally kills its own food, unlike many eagles many of which consume carrion regularly.[2] Among the ungulate prey recorded are three species of deer and five species of goat-antelopes, in addition to piglets of wild boar (Sus scrofa).[90] Only the weight of the roe deer (Capreolus capreolus) has been widely approximated when taken and specimens killed have included: a 10,000g (22lb) deer,[3] a 13,000g (29lb) specimen[91] and even, in the small adult size range for this deer, 17,000g (37lb),[92] all considerably larger than the eagle-owls themselves and far larger than any prey known for other owls.[2] In studies from Bavaria and Austria, the average weight of roe deer caught was only 1,500 and 2,500g (3.3 and 5.5lb), indicating very young deer being typically taken.[66][90] Even if taken as newborn kids, fawns or calves, the young of other ungulates taken would weigh at least 2,500 to 7,000g (5.5 to 15.4lb), from the birth weight of ibex (Capra ibex) to that of red deer (Cervus elaphus).[93][94] Perhaps even larger, the rare domestic sheep (Ovis aries) taken by eagle-owls can reportedly include “half-grown” individuals.[2] Asian black bear
Asiatic black bears may be occasionally attacked by tigers and brown bears, although leopards[35] and packs of wolves[3] and dholes[13] can also be threats. Eurasian lynxes are a potential predator of cubs.[3] Black bears usually dominate Amur leopards in physical confrontations in heavily vegetated areas, while leopards are uppermost in open areas, though the outcome of such encounters is largely dependent on the size of the individual animals.[36] Leopards have been known to prey on cubs younger than two years old.[35] True owl
While typical owls (hereafter referred to simply as owls) vary greatly in size, with the smallest species, the elf owl, being a hundredth the size of the largest, the Eurasian eagle-owl and Blakiston's fish owl, owls generally share an extremely similar body plan. They tend to have large heads, short tails, cryptic plumage, and round facial discs around the eyes. The family is generally arboreal (with a few exceptions like the burrowing owl) and obtain their food on the wing. The wings are large, broad, rounded, and long. As is the case with most birds of prey, in many owl species females are larger than males. Eurasian eagle-owl
Eagle-owl has been singled out historically as a threat to game species and thus to the economic well-being of landowners, game-keepers and even governmental agencies and as such has been singled out for widespread persecution.[95][96] Local extinctions of Eurasian eagle-owls have been primarily due to persecution. Examples of this including northern Germany in 1830, the Netherlands sometimes in the late nineteenth century, Luxembourg in 1903, Belgium in 1943 and central and western Germany in the 1960s.[97] In trying to determine causes of death for 1476 eagle-owls from Spain, most were unknown and undetermined types of trauma. The largest group that could be determined, 411 birds, was due to collisions, more than half of which were from electrocution, while 313 were due to persecution and merely 85 were directly attributable to natural causes. Clearly, while pylon safety is perhaps the most serious factor to be addressed in Spain, persecution continues to be a massive problem for Spanish eagle-owls. Of seven European nations where modern Eurasian eagle-owl mortality is well-studied, continual persecution is by far the largest problem in Spain, although also continues to be serious (often comprising at least half of studied mortality) in France. From France and Spain, nearly equal numbers of eagle-owls are poisoned (for which raptors might not be the main target), or shot intentionally.[98][99] Wolf
The majority of victims of predatory wolf attacks are children under the age of 18 and, in the rare cases where adults are killed, the victims are almost always women. Cases of rabid wolves are low when compared to other species, as wolves do not serve as primary reservoirs of the disease, but can be infected by animals such as dogs, jackals and foxes. Incidents of rabies in wolves are very rare in North America, though numerous in the eastern Mediterranean, Middle East and Central Asia. Wolves apparently develop the "furious" phase of rabies to a very high degree which, coupled with their size and strength, makes rabid wolves perhaps the most dangerous of rabid animals, with bites from rabid wolves being 15 times more dangerous than those of rabid dogs. Rabid wolves usually act alone, travelling large distances and often biting large numbers of people and domestic animals. Most rabid wolf attacks occur in the spring and autumn periods. Unlike with predatory attacks, the victims of rabid wolves are not eaten, and the attacks generally only occur on a single day. The victims are chosen at random, though the majority of cases involve adult men. During the 50 years to 2002, there were eight fatal attacks in Europe and Russia, and more than 200 in south Asia. Between 2005–2010, two people were killed in North America. Eurasian rock pipit
The Eurasian rock pipit is hunted by birds of prey including the Eurasian sparrowhawk. As with other members of its genus, it is a host of the common cuckoo, a brood parasite. Eggs laid by cuckoos that specialise in using pipits as their hosts are similar in appearance to those of the pipit.
The Eurasian rock pipit is also a host to the flea "Ceratophyllus borealis", and several other flea species in the genera "Ceratophyllus" and "Dasypsyllus". The Eurasian rock pipit can benefit from parasitism of the common periwinkle "Littorina littoria" by the castrating trematode "Parorchis acanthus". Beaches can become attractive where the decline of the periwinkle results in more ungrazed algae, with corresponding increases in invertebrates and a greater diversity of smaller "Littorina" snails as food for the pipits. European jackal
The European jackal (Canis aureus moreoticus), also known as the Caucasian jackal[2] or reed wolf[3] is a subspecies of golden jackal native to Southeast Europe, Asia Minor and the Caucasus. It was first described in 1833 by French naturalist Isidore Geoffroy Saint-Hilaire during the Morea expedition.[4] In Europe, there are an estimated 70,000 jackals.[5] Though mostly found in scattered populations within Eastern Europe, its range has grown to encompass parts of its former Eastern European range, as well as in Western Europe, which is thought to be attributable to a decline in grey wolf populations.[6][7][8] Eurasian sparrowhawk
Natural predators of the Eurasian sparrowhawk include the barn owl, the tawny owl, the northern goshawk, the peregrine falcon, the golden eagle, the eagle owl, the red fox, the stone marten and the pine marten. Ornimegalonyx
One of the largest living owls, the Eurasian eagle owl ("Bubo bubo"), reaches 4 kg in weight, and Peters (page 188) has reported them taking roe deer fawns that weigh 17 kg as prey This suggests that "Ornimegalonyx" could have killed prey of 35 kg or more. Modern owls are known to use a pouncing strategy where they drop from elevated perches onto prey, spreading their wings only just before hitting their target. The modern kakapo ("Strigops habroptilus") is a flightless island parrot and is convergent, in some ways, with owls. Like "Ornimegalonyx", it is the largest and heaviest member of its order, it has reduced wings, and a reduced keel of the sternum, but it can parachute by leaping from trees with its wings outspread, potentially covering several meters at an angle of descent less than 45 degrees. Eurasian eagle-owl
In Engadin, Switzerland, the male eagle-owl hunts until the young are 4 to 5 weeks old and the female spends all her time brooding at the nest. After this point, the female gradually resumes hunting from both herself and the young and thus provides a greater range of food for the young.[6][14] While it may seem contrary to the species’ highly territorial nature, there is one verified cases of polygamy in Germany, with a male apparently mating with two females, and cooperative brooding in Spain, with a third adult of undetermined sex helping a breeding pair care for the chicks.[72][73] The response of Eurasian eagle-owls to humans approaching at the nest is quite variable. The species is often rather less aggressive than some other owls, including related species like the spot-bellied eagle-, great horned and snowy owls, many of the northern Strix species and even some rather smaller owl species, which often fearlessly attack any person found to be nearing their nests. Occasionally, if a person climbs to an active nest, the adult female eagle-owl will do a distraction display, in which they feign an injury. This is an uncommon behaviour in most owls and most often associated with small birds trying to falsely drawl the attention of potential predators away from their offspring.[6] More commonly, the female flies off and abandons her nest temporarily, leaving the eggs or small nestlings exposed, when a human approaches it.[14] Occasionally, if cornered both adults and nestlings will do an elaborate threat display, also rare in owls in general, in which the eagle-owls raise their wings into a semi-circle and puff up their feathers, followed by a snapping of their bills. Apparently eagle-owls of uncertain and probably exotic origin in Britain are likely to react aggressively to humans approaching the nest.[74] Also, aggressive encounters involving eagle-owls around their nest, despite being historically rare, apparently have increased in recent decades in Scandinavia.[5] The discrepancy of aggressiveness at the nest between the Eurasian eagle-owl and its Nearctic counterpart may be correlated to variation in the extent of nest predation that the species endured during the evolutionary process.[6] Eurasian sparrowhawk
The Eurasian sparrowhawk's adaptation for feeding on birds has brought it into conflict with humans; in the 19th century it was described as ""the great enemy of small quadrupeds and birds, and often very destructive to young chicks in poultry-yards in the breeding season"" and ""very destructive to partridges."" Writing for gamekeepers in 1851, T.B. Johnson recommended that: ""The nest of this bird should be diligently sought... and destroyed, shooting the parent birds first, if possible.""
It was written in 1870 that ""The sparrowhawk is perhaps only the true enemy of the game-preserver; though at the same time it is probable that if the good and evil it does were justly weighed, the balance would be in favour of the hawk, its favourite quarry being the wood pigeon, which is now increasing to an extent injurious to agriculture."" 18th century parish records for Aldworth, Berkshire, in southern England, show that payments were made for 106 Eurasian sparrowhawks' heads, at the same time as efforts were being made to control the numbers of sparrows. Wolf
Wolves kill dogs on occasion, with some wolf populations relying on dogs as an important food source. In Croatia, wolves kill more dogs than sheep, and wolves in Russia appear to limit stray dog populations. Wolves may display unusually bold behavior when attacking dogs accompanied by people, sometimes ignoring nearby humans. Wolf attacks on dogs may occur both in house yards and in forests. Wolf attacks on hunting dogs are considered a major problem in Scandinavia and Wisconsin. The most frequently killed hunting breeds in Scandinavia are harriers, with older animals being most at risk, likely because they are less timid than younger animals, and react to the presence of wolves differently. Large hunting dogs such as Swedish elkhounds are more likely to survive wolf attacks because of their better ability to defend themselves. Argali
Although they are locally sympatric with Siberian ibex, the two species have differing habitat and pasture preferences, reducing likely competition. In Tibet, the argali must regularly compete with other grazing species for pasture, including Tibetan antelope, bharal, Thorold's deer and wild yaks. Competition is most serious with livestock, especially domestic yak and domestic sheep, with which argali are frequently forced to intermingle and from which they often catch diseases and parasites. The main predator of argali are gray wolves, which often exploit harsh winter conditions (such as deep snow) to capture the wild sheep, though they can and do take specimens of any age or condition year around. Where not locally extirpated, snow leopards and leopards are also predators of argali of any age. Eurasian lynx and wolverines may seldom kill argali to at least the size of winter-weakened ewes. Red foxes and domestic dogs (largely those kept by sheep-herders) will prey on lambs. Cinereous vultures, lammergeiers and golden eagles have been observed circling herds of ewes with lambs in a possibly predatory manner and remains of argali lambs have been observed in golden eagle nests. Smaller predators, such as raptorial birds and smaller mammalian carnivores, are attacked by mother ewes, but in the presence of larger predators, the ewes quickly run away with the lambs following them. Eurasian eagle-owl
Apparently, the point at which the chicks venture out of the nest is driven by the location of the nest. In elevated nest sites, chicks usually wander out of the nest at 5 to as late as 7 weeks of age, but have been recorded leaving the nest if the nest is on the ground as early as 22 to 25 days old.[14] The chicks can walk well at five weeks of age and by seven weeks are taking short flights. Hunting and flying skills are not tested prior to the young eagle-owls leaving the nest. Young Eurasian eagle-owls leave the nest by 5–6 weeks of age and typically can be flying weakly (a few metres) by about 7–8 weeks of age. Normally, they are cared for at least another month. By the end of the month, the young eagle-owls are quite assured fliers.[6] There are a few confirmed cases of adult eagle-owls in Spain feeding and caring for post-fledgling juvenile eagle-owls that were not their own.[81] Dietary biology of the Eurasian eagle-owl
Generally speaking, there appears to be rather strictly adhered size hierarchy among birds of prey and the very largest raptorial prey attacked by Eurasian eagle-owl tend to roughly equal to their own size. Larger raptors, such as eagles and vultures, seem to be largely invulnerable to eagle-owls. However, in Scandinavia, there are two cases of eagle-owls preying on “fairly large” nestlings of white-tailed eagles (Haliaeetus albicilla).[126] Given the size, average adult weight of 4,780g (10.54lb), and formidable character of this eagle, it is possible that the young of other raptors larger than themselves may too be attacked. Eastern imperial eagles (Aquila heliaca), which are nearly as large as the white-tailed eagle at an average weight of 3,215g (7.088lb), have been killed by eagle-owls in Kazakhstan.[139] Remarkable, considering the greater threat that the eagle normally poses to the eagle-owl than vica versa, it appeared a golden eagle was amongst the prey remains found around a nest in the French Pyrenees.[140] Cases in Spain where large, formidable birds of prey, the Egyptian vulture (Neophron percnopterus) and Bonelli's eagle, that are roughly equal in size to the eagle-owls, both weighing just over 2,000g (4.4lb), have been predated, these seem to be taken from the nest or shortly after independence and rare occurrences.[60][141] However, in Turkey, the eagle-owl is apparently a regular and serious predator of Bonelli's eagles.[142] The Eurasian eagle-owl predates the largest members of the most species-rich diurnal raptor genera: the 900g (2.0lb) northern goshawks from the Accipiter genus, the 1,375g (3.031lb) upland buzzards from the Buteo genus and the 1,460g (3.22lb) gyrfalcons (F. rusticolus) of the Falco genus.[112] Additional large raptors, i.e. those that can average 1,000g (2.2lb) or more in body mass, taken as prey include 1,485g (3.274lb) osprey (Pandion haliaetus), the 1,080g (2.38lb) red kites (Milvus milvus), 1,700g (3.7lb) short-toed eagles (Circaetus gallicus), the 2,205g (4.861lb) greater spotted eagle (Clanga clanga), the 1,370g (3.02lb) lesser spotted eagle (Clanga pomarina), and the rough-legged buzzards (Buteo lagopus) and saker falcons (Falco cherrug), in both of which females average more than 1,000g (2.2lb).[2][60][139][143][144][145] The taking of rough-legged buzzards and snowy owls must be confined to full-grown victims, since they nest further north than Eurasian eagle-owls.[2] Eurasian eagle-owls also hunt the smallest raptors available, including those such as lesser kestrels (Falco naumanni) and Japanese sparrowhawks (Accipiter gularis) that weigh less than 150g (5.3oz).[83] Some of these are cases of eagle-owls killing nestlings or fledglings but they can easily overtake adult buzzards, goshawks and falcons of any size.[2] American robin
Juvenile robins and eggs are preyed upon by squirrels, snakes, and some birds, such as blue jays, California scrub jays, Steller's jay, common grackles, American crows, and common ravens. Adults are primarily taken by "Accipiter" hawks, cats, dogs, and larger snakes (especially rat snakes). They may be taken by nearly every variety of North American accipitrid, from the smallest, the sharp-shinned hawk, to one of the two largest, the golden eagle, most every North American falcon from the smallest, the American kestrel, to the largest, the gyrfalcon, and almost all owl species from northern pygmy owls to snowy owls. Overall, 28 raptorial bird species are known to hunt robins. Adult robins are most vulnerable when distracted by breeding activities though may also be attacked on the ground or even in flight. However, when feeding in flocks, the American robin is able to remain vigilant and watch other flock members for reactions to predators. Western barn owl
The Eurasian eagle-owl ("B. bubo") are noted predators of barn owls. In Africa, the principle predators of barn owls are Verreaux's eagle-owls and cape eagle-owls. In Europe, although less dangerous than the eagle owl, the chief diurnal predators are the northern goshawk ("Accipiter gentilis") and the common buzzard ("Buteo buteo"). About a dozen other large diurnal raptors and owls have also been reported as predators of barn owls, ranging from the scarcely larger tawny owl to the golden eagle. The goshawk and the eagle owl are on the increase because of the greater protection these birds now receive.  Dietary biology of the Eurasian eagle-owl
What all primary rodent prey species share is that they are either nocturnal or crepuscular and are often common to abundant in openings of woods and rocky environments. The reason Eurasian eagle-owls take rats, which associate rather closely with humans, much more regularly than they take house mice (Mus musculus) is not their larger size (many other rodents regularly taken by eagle-owls are as small or smaller than a house mouse) but the rat's ability to flourish along the edges of crop fields, refuse dumps, roadsides and abandoned buildings and fields, whereas the mice are more closely tied to active human habitations. A single refuse dump can host several thousand rats and eagle-owl territories that include dumps can locally expect higher productivity due to the abundance of this food source.[30][52][53] Squirrels are readily predated but, being diurnal, are largely unavailable to this and other owls. When they are captured, it is presumably around dawn or dusk from their tree hole, in species such as the widespread 315g (11.1oz) red squirrel (Sciurus vulgaris), or burrow entrance, in the case of ground squirrels, most regularly recorded as prey in Asia Minor and the Central Asia. A few specimens of the 2,000g (4.4lb) woolly flying squirrels (Eupetaurus cinereus), the largest of the world's flying squirrels and one of the rarest, were the only identified foods for Eurasian eagle-owls in northern Pakistan alongside some European hares.[54] Although not common in the diet, a few species of marmot have been taken and may be an important aspect of the prey biomass. In Europe, adult-sized alpine marmots, (Marmota marmota) have been killed.[55] However, the average weight of Tarbagan marmots (Marmota sibirica) taken in Mongolia was only 1,500g (3.3lb) and that of alpine marmots in Engadin, Switzerland was only 2,000g (4.4lb). These obviously comprising young marmots as adults have average weights from 3,500 to 7,000g (7.7 to 15.4lb), from spring low weights to pre-hibernation weights during autumn hypophagia.[51][56] Other than marmots, the largest rodent known to be hunted by Eurasian eagle-owls is the introduced aquatic rodents, the muskrat (Ondatra zibethica), which in one study estimated to average 1,300g (2.9lb) when taken, and the nutria (Myocastor coypus), equal in size to the large marmots.[57][58][59] Eurasian eagle-owl
The great size, bulky, barrel-shaped build, erect ear tufts and orange eyes render this as a distinctive species. Other than general morphology, the above features differ markedly from those of two of the next largest subarctic owl species in Europe and western Asia, which are the great grey owl and the greyish to chocolate-brown Ural owl (Strix uralensis), both of which have no ear tufts and have a distinctly rounded head, rather than the blocky shape of the eagle-owl’s head.[4][14] The snowy owl is obviously distinctive from most eagle-owls, but during winter the palest Eurasian eagle-owl race (B. b. sibiricus) can appear off-white. Nevertheless, the latter is still distinctively an ear-tufted Eurasian eagle-owl and lacks the pure white background colour and variable black spotting of the slightly smaller species (which has relatively tiny, vestigial ear tufts that have only been observed to have flared on rare occasions).[5][14] The long-eared owl has a somewhat similar plumage to the eagle-owl but is considerably smaller (an average female eagle-owl may be twice as long and ten times heavier than an average long-eared owl).[28] Eurasian pygmy owl
The diet of the Eurasian pygmy owl includes mostly small mammals, such as voles, lemmings, bats, and mice, and small birds such as thrushes, crossbills, chaffinches, and leaf-warblers. They are able to catch birds in flight. Other prey items may include lizards, fish, and insects. The owl may store food during the winter. Tawny owl
Predators of the tawny owl include large birds such as Ural owls, eagle owls, northern goshawks, golden eagles, and common buzzards. Pine martens may raid nests, especially where artificial nest boxes make the owls easy to find, and several instances have been recorded of Eurasian jackdaws building nests on top of a brooding female tawny owl leading to the death of the adult and chicks. A Danish study showed that predation by mammals, especially red foxes, was an important cause of mortality in newly fledged young, with 36% dying between fledging and independence. The mortality risk increased with fledging date from 14% in April to more than 58% in June, and increasing predation of late broods may be an important selective agent for early breeding in this species. Eurasian eagle-owl
The male selects breeding sites and advertises their potential to the female by flying to them and kneading out a small depression (if soil is present) and making staccato notes and clucking noises. Several potential sites may be presented, with the female selecting one.[14] Like all owls, Eurasian eagle-owls do not build nests or add material but nest on the surface or material already present. Eurasian eagle-owls normally nest on rocks or boulders, most often utilizing cliff ledges and steep slopes, as well as crevices, gullies, holes or caves. Rocky areas that also prove concealing woodlots as well as, for hunting purposes, that border river valleys and grassy scrubland may be especially attractive.[6][69] If only low rubble is present, they will nest on the ground between rocks.[14] Often, in more densely forested areas, they’ve been recorded nesting on the ground, often among roots of trees, under large bushes and under fallen tree trunks.[6] Steep slopes with dense vegetation are preferred if nesting on the ground, although some ground nests are surprisingly exposed or in flat spots such as in open spots of the taiga, steppe, ledges of river banks and between wide tree trunks.[14] All Eurasian eagle-owl nests in the largely forested Altai Krai region of Russia were found to be on the ground, usually at the base of pines.[70] This species does not often use other bird’s nests as does the great horned owl, which often prefers nests built by other animals over any other nesting site.[6] The Eurasian eagle-owl has been recorded in singular cases using nests built by common buzzards (Buteo buteo), golden eagle, greater spotted (Clanga clanga) and white-tailed eagles (Haliaeetus albicilla), common ravens (Corvus corax) and black storks (Ciconia nigra). Among the eagle-owls of the fairly heavily wooded wildlands of Belarus, they more commonly utilize nests built by other birds than most eagle-owls, i.e. stork or accipitrid nests, but a majority of nests are still located on the ground.[71] This is contrary to the indication that ground nests are selected only if rocky areas or other bird nests are unavailable, as many will utilize ground nests even where large bird nests seem to be accessible.[14][71] Tree holes being used for nesting sites are even more rarely recorded than nests constructed by other birds. While it may be assumed that the eagle-owl is too large to utilize tree hollows, when other large species like the great grey owl have never been recorded nesting in one, the even more robust Blakiston's fish owl nests exclusively in cavernous hollows.[4][6] The Eurasian eagle-owl often uses the same nest site year after year.[24] Great horned owl
The great horned owl (Bubo virginianus), also known as the tiger owl (originally derived from early naturalists' description as the "winged tiger" or "tiger of the air") or the hoot owl,[2] is a large owl native to the Americas. It is an extremely adaptable bird with a vast range and is the most widely distributed true owl in the Americas.[3] Its primary diet is rabbits and hares, rats and mice, and voles, although it freely hunts any animal it can overtake, including rodents and other small mammals, larger mid-sized mammals, birds, reptiles, amphibians, and invertebrates. In ornithological study, the great horned owl is often compared to the Eurasian eagle-owl (Bubo bubo), a closely related species, which despite the latter's notably larger size, occupies the same ecological niche in Eurasia, and the red-tailed hawk (Buteo jamaicensis), with which it often shares similar habitat, prey, and nesting habits by day, thus is something of a diurnal ecological equivalent.[4] The great horned owl is one of the earliest nesting birds in North America, often laying eggs weeks or even months before other raptorial birds.[5] Eurasian eagle-owl
The Eurasian eagle-owl at one time occurred naturally in Great Britain. Some, including the RSPB have claimed that this was probably by about 10,000–9,000 years ago after the last ice age but fossil remains found in Meare Lake Village have indicated the eagle-owl occurring as recently as roughly 2,000 years ago in the fossil record.[104][105] The lack of presence of the Eurasian eagle-owl in British folklore or writings in recent millennium may indicate the lack of occurrence by this species there.[103] The flooding of the land bridge between Britain and continental Europe may have been responsible for their extirpation as they only disperse over limited distances, although early human persecution presumably played a role as well. Some reportages of eagle-owls in Britain have been revealed to actually be great horned owls or Indian eagle-owls, the latter a particularly popular owl in falconry circuits.[103] Some breeding pairs do still occur in Britain, the exact number of pairs and individuals is not definitely known. The World Owl Trust stated that they believe some eagle-owls occurring in North England and Scotland are naturally occurring, making the flight of roughly 350 to 400km (220 to 250mi) from the west coast of Norway to Shetland and the east coast of Scotland, as well as possibly from the coasts of the Netherlands and Belgium to the south. Although not migratory, eagle-owls can disperse some notable distances in young birds seeking a territory.[104] Prior studies of eagle-owl distribution have indicated a strong reluctance to cross large bodies of water in the species. Many authorities state that the Eurasian eagle-owls occurring in Britain are individuals that have escaped from captivity.[103][106] While, until 19th century, wealthy collectors may have released unwanted eagle-owls, despite press to the contrary, there is no evidence of any organization or individual intentionally releasing eagle-owls recently with the intent to establish a breeding population.[103] Many feel that the eagle-owl would be classified as an "alien" species. Due to its predatory abilities, many, especially those in the press, have expressed alarm of their effect on "native" species.[107] From 1994 to 2007, 73 escaped eagle-owls were not registered as returned, while 50 escapees were re-captured.[103] Several recorded breeding attempts have been studied and most were unsuccessful, due in large part to incidental disturbance by humans and some due to direct persecution, with eggs having been smashed.[103] Wolf attack
Although wolf attacks do occur, their frequency varies with geographical location and historical period. Gray wolf attacks are rare because wolves are often subsequently killed, or even extirpated in reaction by human beings. As a result, wolves today tend to live mostly far from people or have developed the tendency and ability to avoid them. The country with the most extensive historical records is France, where nearly 7,600 fatal attacks were documented from 1200 to 1920.[1][2] In modern times, they occur most often in India and neighboring countries. There are few historical records or modern cases of wolf attacks in North America. In the half-century up to 2002, there were eight fatal attacks in Europe and Russia, three in North America, and more than 200 in south Asia.[3] Experts categorize wolf attacks into various types, including rabies-infected, predatory, agonistic, and defensive. Northern goshawk
Outside of the accipitrid group, heavy predation on different varieties of raptorial birds by northern goshawks can continue unabated. Many types of owl are taken and in Europe, the northern goshawk is the second most prolific predator of owls behind the Eurasian eagle owl ("Bubo bubo"). In Bavaria, Germany, the long-eared owl ("Asio otus") was the second most common prey species for nesting goshawks. In the Białowieża Forest of Poland, fairly high numbers of the tawny owl ("Strix alucco") were taken. In all, some 18 species of owl have been recorded in the diet, ranging in size from the Eurasian ("Glaucidium passerinum") and northern pygmy owls ("Glaucidium gnoma") at and , respectively, to all the large northern "Strix" owls including adults and even the great horned owl. Whether adults have ever been killed as prey though is unknown but goshawks have been known to kill great horned owls that they've found near their nests. In addition, about eight species of falcon have been identified in the foods of goshawks. Adult falcons of small species such as kestrels and merlins ("Falco columbarius") can be overpowered quite easily if they can manage to surprise the prey. Larger falcons have turned up in the diet as well, including the prairie falcon ("Falco mexicanus") and the saker falcon ("Falco cherrug"), although possible only nestlings of these species. Brief aerial skirmishes between goshawks and peregrine falcons ("Falco peregrinus") have been described but neither species is known to have killed one another in the wild. In Schleswig-Holstein, Germany, at least four small passerines species were recorded as nesting close to active goshawk nest, due to the incidental shelter that the fierce goshawks inadvertently provides from smaller raptors which are their main predators. Such raptors, including Eurasian kestrels, Eurasian sparrowhawks and long-eared owls, not only avoid goshawk activity where possible but also were found to have lower nest productivity any time they nested relatively close to goshawks per the study. A similar phenomenon, with goshawks inadvertently providing shelter to small passerines, has been recorded in North America as well.
Competition for northern goshawks can also come from mammalian carnivores. Martens, and to a lesser extent other weasels, are presumably one of their more major competitors as their diet often consists of similar prey primarily during spring and summer, tree squirrels and woodland birds, but little has been studied in terms of how the two types of predator effect each other. Most recorded interactions have been predatory, as the goshawk has been recorded preying on a dozen species, from the least weasel ("Mustela nivalis") to the stone marten ("Martes foina"). Northern goshawks have also been recorded as feeding on much bigger predators such as the red fox ("Vulpes vulpes"), the raccoon dog ("Nyctereutes procyonoides") and the striped skunk ("Mephitis mephitis"), but it is not clear whether these were actual kills, as many may be encountered as already dead carrion. Domestic carnivores are sometimes eaten, including dogs and cats, the latter of which has reportedly been taken alive by goshawks. The red fox is a surprisingly considerable competitor for resources with northern goshawks. It was found in Norway that goshawk numbers were higher when voles were at peak numbers, not due to voles as a food source but because foxes were more likely to eat the rodents and ignore grouse, whereas during low vole numbers the foxes are more likely to compete with goshawks over grouse as prey. A decrease of the fox population of Norway due to sarcoptic mange was found result in an increase of grouse numbers and, in turn, northern goshawks. In some areas, red foxes have been found to steal up to half of the goshawks’ kills. Owl
Although humans and owls frequently live together in harmony, there have been incidents when owls have attacked humans. For example, in January 2013, a man from Inverness, Scotland suffered heavy bleeding and went into shock after being attacked by an owl, which was likely a 50-cm tall eagle owl. The photographer Eric Hosking lost his left eye after attempting to photograph a tawny owl, which inspired the title of his 1970 autobiography, "An Eye for a Bird". Stoat
As with the least weasel, mouse-like rodents predominate in the stoat's diet. However, unlike the least weasel, which almost exclusively feeds on small voles, the stoat regularly preys on larger rodent and lagomorph species, and will take down individuals far larger than itself. In Russia, its prey includes rodents and lagomorphs such as European water voles, common hamsters, pikas, and others, which it overpowers in their burrows. Prey species of secondary importance include small birds, fish, and shrews and, more rarely, amphibians, lizards, and insects. In Great Britain, European rabbits are an important food source, with the frequency in which stoats prey on them having increased between the 1960s and mid 1990s since the end of the myxomatosis epidemic. Typically, male stoats prey on rabbits more frequently than females do, which depend to a greater extent on smaller rodent species. British stoats rarely kill shrews, rats, squirrels and water voles, though rats may be an important food source locally. In Ireland, shrews and rats are frequently eaten. In mainland Europe, water voles make up a large portion of the stoat's diet. Hares are sometimes taken, but are usually young specimens. In North America, where the ecological niche for rat and rabbit sized prey is taken by the larger long-tailed weasel, the stoat preys on mice, voles, shrews, and young cottontails. In New Zealand, the stoat feeds principally on birds, including the rare kiwi, kaka, mohua, yellow-crowned parakeet, and New Zealand dotterel. Cases are known of stoats preying on young muskrats. The stoat typically eats about of food a day, which is equivalent to 25% of the animal's live weight. Spanish imperial eagle
The species is classified as Vulnerable by IUCN. Threats include loss of habitat, human encroachment, collisions with pylons (at some point in the early 1980s, powerlines were responsible for 80% of deaths among birds in their first year of life) and illegal poisoning. There has also been a decline in the species' main prey: rabbits have been kept at bay or even declined in some of the areas where the eagle is or could be present as a result of myxomatosis and, most recently, rabbit haemorrhagic disease. Man-eater
Some evidence supports the contention that the African crowned eagle occasionally views human children as prey, with a witness account of one attack (in which the victim, a seven-year-old boy, survived and the eagle was killed), and the discovery of part of a human child skull in a nest. This would make it the only living bird known to prey on humans, although other birds such as ostriches and cassowaries have killed humans in self-defense and a lammergeier might have killed Aeschylus by accident. Various large raptors like golden eagles are reported attacking human beings, but its unclear if they intend to eat them or if they have ever been successful in killing one. Eurasian eagle-owl
The feathers of the ear tufts in Spanish birds (when not damaged) were found to measure from 63.3 to 86.6mm (2.49 to 3.41in).[23] The ear openings (covered in feathers as in all birds) are relatively uncomplicated but are also large, being larger on the right than on the left as in most owls, and proportionately larger than those of the great horned owl. In the female, the ear opening averages 31.7mm (1.25in) on the right and 27.4mm (1.08in) on the left and, in males, averages 26.8mm (1.06in) on the right and 24.4mm (0.96in) on the left.[6] The depth of the facial disc and the size and complexity of the ear opening are directly correlated to the importance of sound in an owl’s hunting behaviour. Examples of owls with more complicated ear structures and deeper facial disc are barn owls, long-eared owls (Asio otus) and boreal owls (Aegolius funereus). Given the uncomplicated structure of their ear openings and relatively shallow, undefined facial disc, hunting by ear is secondary to hunting by sight in the eagle-owl, this seems to be true for Bubo in general. It is likely that more sound-based hunters such as the aforementioned species focus their hunting activity in more complete darkness. Also owls with white throat patches such as the Eurasian eagle-owl are more likely to be active in low light conditions in the hours before and after sunrise and sunset rather than the darkest times in the middle of the night. The boreal and barn owls, to extend these examples, lack obvious visual cues such as white throat patches (puffed up in displaying eagle-owls), again indicative of primary activity being in darker periods.[6][27] Blakiston's fish owl
A wide variety of mammalian prey are described from Japan and becomes most important to the diet during winter. Smaller mammals taken have included martens ("Martes" ssp.) and numerous rodents. Unidentified bats have turned up occasionally in Blakiston's fish owl pellets in the Russian Far East, although bats were much more prominent in the diet of Eurasian eagle-owls there (79 eagle-owl pellets and 10 fish owl pellets had bat remains, respectively). Large mammals are sometimes taken by this species, including hares ("Lepus" ssp.), rabbits, fox, cats ("Felis catus") and small dogs ("Canis lupus familiaris"). Fewer records are known of bird predation, but they are known to capture avian prey such as hazel grouse ("Tetrastes bonasia") and a variety of waterfowl species. A case where a black-crowned night heron ("Nycticorax nycticorax"), a rare species in Japan, was chased in flight by a male fish owl was observed but the heron managed to evade capture. A similar case of a fish owl chasing a grey heron ("Ardea cinerea") has also been reported. Eurasian wolf
In France, historical records compiled by rural historian Jean-Marc Moriceau indicate that during the period 1362–1918, nearly 7,600 people were killed by wolves, of whom 4,600 were killed by non-rabid wolves. Numerous attacks occurred in Germany during the 17th century after the Thirty Years' War, though the majority probably involved rabid wolves. In Latvia, records of rabid wolf attacks go back two centuries. At least 72 people were bitten between 1992-2000. Similarly, in Lithuania, attacks by rabid wolves have continued to the present day, with 22 people having been bitten between 1989-2001. Around 82 people were bitten by rabid wolves in Estonia during the 18th to 19th centuries, with a further 136 people being killed in the same period by non-rabid wolves, though it is likely that the animals involved in the latter cases were a combination of wolf-dog hybrids and escaped captive wolves. Eurasian wolf
The size of Eurasian wolves is subject to geographic variation, with animals in Russia and Scandinavia being larger and bulkier than those residing in Western Europe, having been compared by Theodore Roosevelt to the large wolves of north-western Montana and Washington. Adults from Russia measure in length, in shoulder height, and weigh on average , with a maximum weight of . The largest on record was killed after World War II in the Kobelyakski Area of the Poltavskij Region in the Ukrainian SSR, and weighed . Larger weights of have been reported in Ukraine, though the circumstances under which these latter animals were weighed are not known. Although similar in size to central Russian wolves, Swedish and Norwegian wolves tend to be more heavily built with deeper shoulders. One wolf killed in Romania was recorded to have weighed . In Italian wolves, excepting the tail, body length ranges between 110–148 cm, while shoulder height is 50–70 cm. Males weigh between and rarely . The now extinct British wolves are known to have reached similar sizes to Arctic wolves. Eurasian eagle-owl
Unanimously, biologists studying eagle-owl mortality and conservation factors have recommended to proceed with the proper insulation of electric wires and pylons in areas where the species is present. As this measure is labour-intensive and therefore rather expensive, few efforts have actually been made to insulate pylons in areas with few fiscal resources devoted to conservation such as rural Spain.[98] Dietary biology of the Eurasian eagle-owl
Wild birds found in their diet have ranged in size from the 9.5g (0.34oz) Eurasian wren (Troglodytes troglodytes) to about 15 species weighing over 2,000g (4.4lb).[18] One of the largest wild adult bird verified as prey was the 3,300g (7.3lb) greylag goose (Anser anser).[23] Other large species have been hunted, some may be cases of nest robbery rather than large adults but none are heavier than the largest mammalian prey that eagle-owls have taken including greater white-fronted goose (Anser albifrons), bar-headed goose (Anser indicus), great cormorant (Phalacrocorax carbo), Himalayan snowcock (Tetraogallus himalayensis) and demoiselle crane (Anthropoides virgo), all averaging around 2,500g (5.5lb), the 3,500g (7.7lb) swan goose (Anser cygnoides), the 5,500g (12.1lb) common crane (Grus grus) and the 8,000g (18lb) (between the dimorphic sexes) great bustard (Otis tarda).[14][18][76][97][104][105] Eurasian eagle-owls have also hunted adult male western capercaillie, which average about 4,100g (9.0lb), although usually the much smaller females, at 1,800g (4.0lb), are more regularly taken.[15] Although they rarely take domestic birds, the range of sizes killed is just as dramatic, from loose budgerigars (Melopsittacus undulatus), weighing only 29g (1.0oz), to domestic turkeys, which may easily weigh over 8kg (18lb).[23][27] Red fox
Red foxes may kill small mustelids like weasels, stone martens, pine martens, stoats, kolonoks, polecats and young sables. Eurasian badgers may live alongside red foxes in isolated sections of large burrows. It is possible that the two species tolerate each other out of mutualism; foxes provide badgers with food scraps, while badgers maintain the shared burrow's cleanliness. However, cases are known of badgers driving vixens from their dens and destroying their litters without eating them. Wolverines may kill red foxes, often while the latter are sleeping or near carrion. Foxes in turn may kill unattended young wolverines. Cinereous vulture
The cinereous vulture has declined over most of its range in the last 200 years in part due to poisoning by eating poisoned bait put out to kill dogs and other predators, and to higher hygiene standards reducing the amount of available carrion; it is currently listed as Near Threatened. Vultures of all species, although not the target of poisoning operations, may be shot on sight by locals. Trapping and hunting of cinereous vultures is particularly prevalent in China and Russia, although the poaching for trophy hunting are also known for Armenia, and probably other countries in Caucasus. Perhaps an even greater threat to this desolation-loving species is development and habitat destruction. Nests, often fairly low in the main fork of a tree, are relatively easy to access and thus have been historically compromised by egg and firewood collectors regularly. The decline has been the greatest in the western half of the range, with extinction in many European countries (France, Italy, Austria, Poland, Slovakia, Albania, Moldova, Romania) and its entire breeding range in northwest Africa (Morocco and Algeria). They no longer nest in Israel. More recently, protection and deliberate feeding schemes have allowed some local recoveries in numbers, particularly in Spain, where numbers increased to about 1,000 pairs by 1992 after an earlier decline to 200 pairs in 1970. This colony have now spread its breeding grounds to Portugal. Elsewhere in Europe, very small but increasing numbers breed in Bulgaria and Greece, and a re-introduction scheme is under way in France. Trends in the small populations in Ukraine (Crimea) and European Russia, and in Asian populations, are not well recorded. In the former USSR, it is still threatened by illegal capture for zoos, and in Tibet by rodenticides. It is a regular winter visitor around the coastal areas of Pakistan in small numbers. As of the turn of the 21st century, the worldwide population of cinereous vultures is estimated at 4500–5000 individuals.
The hebrew word for "eagle" is also used for the Cinereous vulture. As such, biblical passages alluding to eagles might actually be referring to this bird instead. Eurasian eagle-owl
Besides the female being larger, there is little external sexual dimorphism in the Eurasian eagle-owl although the ear tufts of males reportedly tend to be more upright than those of females.[4] When an eagle-owl is seen on its own in the field, it is generally not possible to distinguish the individual’s sex. Gender determination by size is possible via in hand measurements.[23] Reportedly, in some populations the female may be slightly darker on average than the male.[5] The plumage coloration across at least 13 accepted subspecies can be highly variable. The upper parts may be brown-black to tawny-buff to pale creamy gray, typically showing dense freckling on the forehead and crown, stripes on the nape, sides and back of the neck, and dark splotches on the pale ground colour of the back, mantle and scapulars. A narrow buff band, freckled with brown or buff, often runs up from the base of the bill, above the inner part of the eye and along the inner edge of the black-brown ear tufts. The rump and upper tail-coverts are delicately patterned with dark vermiculations and fine wavy barring, the extent of which varies with subspecies. The underwing coverts and undertail coverts are similar but tend to be more strongly barred in brownish-black.[14] The primaries and secondaries are brown with broad dark brown bars and dark brown tips, and grey or buff irregular lines. A complete moult takes place each year between July and December.[24] The facial disc is tawny-buff, speckled with black-brown, so densely on the outer edge of the disc as to form a "frame" around the face. The chin and throat are white with a brownish central streak. The feathers of the upper breast generally have brownish-black centres and reddish-brown edges except for the central ones which have white edges. The chin and throat may appear white continuing down the center of the upper breast. The lower breast and belly feathers are creamy-brown to tawny buff to off-white with a variable amount of fine dark wavy barring, on a tawny-buff ground colour. The legs and feet (which are feathered almost to the talons) are likewise marked on a buff ground colour but more faintly. The tail is tawny-buff, mottled dark grey-brown with about six black-brown bars. The bill and feet are black. The iris is most often orange but is fairly variable. In some European birds, the iris is a bright reddish, blood-orange colour but then in subspecies found in arid, desert-like habitats, the iris can range into an orange-yellow colour (most closely related species generally have yellowish irises, excluding the Indian eagle-owl).[14] European badger
Badgers prey on rabbits throughout the year, especially during times when their young are available. They catch young rabbits by locating their position in their nest by scent, then dig vertically downwards to it. In mountainous or hilly districts, where vegetable food is scarce, badgers rely on rabbits as a principal food source. Adult rabbits are usually avoided, unless they are wounded or caught in traps. They consume them by turning them inside out and eating the meat, leaving the inverted skin uneaten. Hedgehogs are eaten in a similar manner. In areas where badgers are common, hedgehogs are scarce. Some rogue badgers may kill lambs, though this is very rare; they may be erroneously implicated in lamb killings through the presence of discarded wool and bones near their setts, though foxes, which occasionally live alongside badgers, are often the culprits, as badgers do not transport food to their earths. They typically kill lambs by biting them behind the shoulder. Poultry and game birds are also taken only rarely. Some badgers may build their setts in close proximity to poultry or game farms without ever causing damage. In the rare instances in which badgers do kill reared birds, the killings usually occur in February–March, when food is scarce due to harsh weather and increases in badger populations. Badgers can easily breach bee hives with their jaws, and are mostly indifferent to bee stings, even when set upon by swarms. Western capercaillie
Mammalian predators known to take capercaillie include Eurasian lynx ("Lynx lynx") and gray wolf ("Canis lupus"), although they prefer slightly larger prey. Meanwhile, European pine martens ("Martes martes"), beech martens ("Martes foina"), brown bears ("Ursus arctos"), wild boars ("Sus scrofa") and red foxes ("Vulpes vulpes") take mostly eggs and chicks but can attack adults if they manage to ambush the often wary birds. In Sweden, western capercaillies are the primary prey of the golden eagle ("Aquila chrysaetos"). Large numbers are taken by northern goshawks ("Accipiter gentilis"), including adults but usually young ones, and Eurasian eagle-owls ("Bubo bubo") will occasionally pick off a capercaillie of any age or size; they normally prefer mammalian foods. White-tailed eagles ("Haliaeetus albicilla") are more likely to take water birds than upland-type birds but have been recorded preying on capercaillie around the White Sea. Coyote
The coyote is roughly the North American equivalent to the Eurasian golden jackal. Likewise, the coyote is highly versatile in its choice of food, but is primarily carnivorous, with 90% of its diet consisting of meat. Prey species include bison, deer, sheep, rabbits, rodents, birds, amphibians (except toads), lizards, snakes, fish, crustaceans, and insects. Coyotes may be picky over the prey they target, as animals such as shrews, moles, and brown rats do not occur in their diet in proportion to their numbers. More unusual prey include fishers, young black bear cubs, harp seals and rattlesnakes. Coyotes kill rattlesnakes mostly for food (but also to protect their pups at their dens) by teasing the snakes until they stretch out and then biting their heads and snapping and shaking the snakes. Birds taken by coyotes may range in size from thrashers, larks and sparrows to adult wild turkeys and, possibly, brooding adult swans and pelicans. If working in packs or pairs, coyotes may have access to larger prey than lone individuals normally take, such as various prey weighing more than . In some cases, packs of coyotes have dispatched much larger prey such as adult "Odocoileus" deer, cow elk, pronghorns and wild sheep, although the young fawn, calves and lambs of these animals are considerably more often taken even by packs, as well as domestic sheep and domestic calves. In some cases, coyotes can bring down prey weighing up to . When it comes to adult ungulates such as wild deer, they often exploit them when vulnerable such as those that are infirm, stuck in snow or ice, otherwise winter-weakened or heavily pregnant, whereas less wary domestic ungulates may be more easily exploited. White-tailed eagle
White-tailed eagles are known to prey on about 170 species of bird, the most diverse group in their prey spectrum. While hunting birds, this massive, relatively slow-flying eagle requires an element of surprise, with often a tactful use of cover or bright sunlight upon the approach from a nearby perch. For example, grey herons ("Ardea cinerea") have been caught after an eagle used a low flight over turbulent water to ambush them. However, even with a stealthy attack, the waterfowl favored in the avian diet tend to be highly wary and will more often than not escape. The white-tailed eagles must then attack birds at times of vulnerability or injury, or will often utilize the prey's escape tactics against them. Diving ducks and other diving water birds will be taken preferentially where they are available. In hunting diving birds, they utilize a technique of forcing the birds to dive repeatedly to avoid attacks, until the victim is exhausted from the efforts and can then be caught. Usually while hunting like this, the white-tailed eagle tends to circle low to stay close to the intended victim, with birds diving in shallower water being preferred. Ducks with conspicuous plumage, such as male common eiders ("Somateria mollissima"), with their pale plumage, may be easier to see under water and so may be taken somewhat more via this hunting method. Beyond waterfowl, both loons and grebes have been seen to be successfully hunted in this way. Eagles were recorded doing between 7 and 12 attacks on eiders in Russia and were usually successful in procuring prey. Even as many as 65 passes have recorded in less 45 minutes but more than a few attacks also start to exhaust the eagle, as one immature gave up after 15-28 attempts at a little grebe ("Tachybaptus ruficollis"). While bald eagles may attack diving ducks in the same way, they appear to do so somewhat less regularly and successfully. White-tailed eagles usually have less success hunting dabbling ducks because their normal predator response behavior is to take flight. In one instance, a mallard was caught while flying in mid-air, but usually the much larger eagle is unable to capture ducks in flight. While somewhat less swift in flight, healthy geese can usually outpace a heavier eagle as well and one bean goose ("Anser fabalis") was even recorded to have defended itself successfully against an eagle's attack even though this goose was injured. White-tailed eagles often hunt dabbling ducks and geese most successfully when they are molted into their eclipse plumage which renders them temporarily flightless. Swans during winter may find themselves forced to land due to their bulk on a sheet of ice over water if they can find no open water, which can make their feet stuck to the ice. White-tailed eagles have been recorded utilizing this disability to attack and kill swans. They’ve also been seen to attack numerous waterfowl when the birds are injured by buckshot from duck hunters. Due to their status as enemy of other large birds, they are frequently mobbed by them and white-tailed eagles have been recorded utilizing violent mobbings to suddenly turn over in flight and predaceously grab one of the birds mobbing them, including large gulls and even a northern goshawk ("Accipiter gentilis"). As an opportunistic predator, it often takes young birds freely as well as adult and fledged juvenile birds. In general, due to different nesting situations, white-tailed eagles instead of dabbling or diving water birds usually attack the more conspicuous or open nests of gulls, those of several other types of seabird, large corvids or other accipitrids. In Germany and Scotland, up to 86% of gulls taken were nestlings and juveniles. Cases of white-tailed eagles eating eggs, instead of nestlings or older birds, is considered rare. Nonetheless, they have been recorded eating a few eggs, which they may carry in their beaks rather in their feet, of some seabirds such as kittiwakes, eiders, cormorants and gulls. East Siberian taiga
This region contains the highest number of brown bears ("Ursus arctos collaris"), Eurasian wolf ("Canis lupus"), moose ("Alces alces") and wild reindeer ("Rangifer tarandus") in Russia. Further south mammals in the East Siberian taiga include Siberian musk deer ("Moschus moschiferus"), Altai wapiti also known as Asian elk ("Cervus canadensis sibiricus") and wild boar ("Sus scrofa"). Birds of this ecoregion include the golden eagle ("Aquila chrysaetos"), peregrine falcon ("Falco peregrinus"), osprey ("Pandion haliaetus"), black stork ("Ciconia nigra"), hooded crane ("Grus monacha"), carrion crow ("Corvus corone"), the Siberian blue and rufous-tailed robins ("Luscinia cyane" and "L. sibilans", respectively), the thrush nightingale ("Luscinia luscinia"), Pallas's rosefinch ("Carpodacus roseus"), Pacific swift ("Apus pacificus") and Baikal teal ("Anas formosa"). White-tailed eagle
Mammals are usually a quite secondary component of the diet. Although usually better represented than other non-fish and bird prey, their regional importance is variable. In known dietary studies, the mammalian contribution can vary from 0.49% to 41% of prey by number. When mammals are most significant to the diet, it usually due to local white-tailed eagles preying on rabbits and hares with some regularity. In some studies from Scotland, the European rabbit ("Oryctolagus cuniculus") and mountain hare ("Lepus timidus") were found to contribute as much as nearly 25% of the diet. A similar contribution of European hares ("Lepus europaeus") was found in the diet from Austria, where hares were the leading prey species making up 24.35% of 349 prey items (with mammals making up 34.67% of the overall diet). In studies from Germany, European hares were taken fairly often but were numerically secondary prey. Given that these rabbits and hares have average mature weights from in rabbits to in European and Arctic hares ("Lepus arcticus"), they can make a hearty contribution to the prey biomass when available (although certainly juveniles are attacked as much if not more so than adult rabbits and hares). Other large mammalian prey can include foxes, with Arctic foxes ("Vulpes lagopus") being the 6th most regular prey species in Greenland and about a dozen red foxes ("Vulpes vulpes") recorded as taken or scavenged in Norway (predaceous attacks on adult red foxes have been reportedly witnessed). In both the offshore islands of Norway, where Arctic hare can be important prey, and Greenland, where the Arctic fox are prey, large numbers of both are taken when their pelage remains white but snow melts prematurely. A white-tailed eagle was once observed to kill and feed on a live adult golden jackal ("Canis auereus") that was trapped in a furbearer's trap. White-tailed eagles are known to prey on seal pups but most are likely sickly and perhaps both adult and pup seals are most likely to be eaten as carrion. Four Baikal seal ("Pusa sibirica") pups were taken in Lake Baikal. They are considered a predator even for live grey seal ("Halichoerus grypus") pups that weigh at birth. In one instance, a white-tailed eagle reportedly tried to attack an adult harbor seal ("Phoca vitulina") but was immediately dragged into the water and soon surfaced dying with a broken wing. Similarly, in one anecdote, an eagle drowned while apparently attacking an adult harbor porpoise ("Phocoena phocoena"). At least 7 species of mustelid have been recorded in the white-tailed eagle's diet, from the smallest weasel to, rarely, even adult European otters ("Lutra lutra"). Another mustelid, the American mink ("Neovison vison") was introduced as a furbearer to Finland but then became an invasive pest, as a fast-breeding killer that threatens many native species. In turn, Finnish white-tailed eagles have become the main natural control and may inhibit the mink from breeding via heavy predation. Conversely, the white-tailed eagle have not been known to prey on the critically endangered, native European mink ("Mustela lutreola") (perhaps due to its shier habits) which the American mink are known to have been outcompeting in some areas (but the European has mainly declined due to massive overhunting by humans as a furbearer). Kits of larger mammals such as Eurasian ("Castor fiber") and North American beavers ("Castor canadensis") (introduced) and of European badger ("Meles meles") have been found as prey. Wolf hunting
The use of raptors in the hunting of wolves is primarily practised in Central Asia. The Kyrgyz people have traditionally used golden eagles, known as "berkut", to hunt wolves. In the past, wolf pelts provided material for clothes crucial for the survival of the nomadic people in the severe colds. The eagles are used to immobilize the wolves by placing one foot at the back of the neck and another at the flank closer to the heart and lungs. Hunters usually only use eagles against pups, as an adult wolf can cripple in combat even a highly experienced eagle. Losing even one toe or talon will significantly lower the eagle's ability to tackle prey. Only a minor injury to the sinew of a foot may leave the eagle incapable of further hunting. As a wolf is capable of resisting even the best-trained bird, the falconer always keeps near, ready at the first opportunity to help the eagle. This is done carefully, as the wolf, sensing human presence, fights desperately to tear loose from the bird's talons, and the eagle can be severely injured. Because of the violent nature of their work, eagles trained to hunt wolves have shorter life spans. European hedgehog
European hedgehogs may live to ten years of age, although the average life expectancy is three years. Starvation is the most common cause of death, usually occurring during hibernation. If alarmed, the animal will roll into a ball to protect itself. Many potential predators are repelled by its spines, but predation does occur. Remains of hedgehogs have been found in the stomachs of European badgers ("Meles meles"), red foxes ("Vulpes vulpes") and pine martens ("Martes martes"). A large portion of these may be from hedgehog carcasses, especially road-kill. However, hedgehogs tend to be absent from areas where badgers are numerous. Eurasian eagle-owls ("Bubo bubo") and golden eagles ("Aquila chrysaetos") are the only regular avian predators of this species and may even prefer them as prey. The owl, after grabbing the hedgehog by its face, tends to skin the mammal's prickly back with its talons before consumption, resulting in several hedgehog backs being found around eagle-owl roosts and nests. In Spain, reduction of European rabbit ("Oryctolagus cuniculus") numbers due to rabbit haemorrhagic disease has made the European hedgehog one of the top preferred prey species for eagle-owls. Elsewhere, eagle-owls often prefer these hedgehogs to any other prey species, as the hedgehog can comprise up to 23% by number and 30.7% by biomass of eagle-owl prey remains. On the Swedish island of Gotland the golden eagle may take larger numbers of hedgehogs than any other prey due to an otherwise low diversity of native land mammals, although the introduction of European rabbits has shifted the eagle's prey preferences there. Martial eagle
The martial eagle infrequently hunts other birds of prey, perhaps doing so only slightly more often than do crowned eagles and Verreaux's eagles. In comparison, the temperate-zone-dwelling golden eagle is a frequent predator of other birds of prey. This may be due to more scarce prey resources in colder regions forcing eagles to pursue difficult prey such as this more frequently, whereas booted eagles in rich Africa biospheres may not need to do so as much. Nonetheless, a somewhat diverse range of raptorial birds have been identified as prey for martial eagles: the lanner falcon ("Falco biarmicus"), the peregrine falcon ("Falco peregrinus"), the spotted eagle owl ("Bubo africanus") (with a surprisingly large number of 6 found at one nest in Tsavo East), the pale chanting goshawk ("Melierax canorus"), the hooded vulture ("Necrosyrtes monachus") (in one case after a protracted aerial battle), the white-headed vulture ("Trigonoceps occipitalis") and even Africa's largest bird of prey, the Cape vulture ("Gyps coprotheres"). As apex predators, martial eagles are themselves largely invulnerable to predation. A video exists that purportedly depicts a leopard killing a martial eagle but this eagle was misidentified as it actually features a leopard preying on an immature African fish eagle ("Haliaeetus vociferus") (and, at that, one that was possibly grounded for unknown reasons). There are, however, verified (if rare) cases of caracals preying on sleeping martial eagles at night, by climbing trees and pouncing in an ambush. It is possible that leopards may too ambush sleeping eagles but post-fledgling martial eagles are known to be highly wary and healthy individuals a great majority of the time will successfully evade potential dangers by day. Predation on nests of martial eagles, beyond those by humans, are little-known, with no verified depredations known in the literature, but are likely to occur. Dietary biology of the Eurasian eagle-owl
Discreet habitat preferences may coincidentally spare many owls, as owls from the genera Strix, Glaucidium, Aegolius and the 320g (11oz) northern hawk-owl (Surnia ulula) tend to restrict both nesting and their hunting forays to more enclosed areas of woodland than habitats inhabited by the eagle-owls.[112][132] Meanwhile, Asio, Otus, Athene and barn owls owls tend to hunt in more open habitats than the edges favored by eagle-owls.[2] However, habitat preferences are never enough to spare any of these genera from predation by the great eagle-owl. In the Italian Alps, despite differing habitat preferences and partially overlapping prey, several tawny owls were killed by eagle-owls.[133] Woodland nesting owl species tend to nest in tree hollows, many of which are too small for an eagle-owl to access, so are somewhat less likely to be picked off at their nests. Open-country owls that tend to nest in open-access nesting sites like short-eared owls and little owls may be somewhat more vulnerable at the nest. The great numbers of long-eared owls taken, since it often nest in dense, protective thickets, are probably adult or immature owls attempting to hunt. In Europe, Eurasian eagle-owls are generally the only owls to regularly nest in rocky habitats. This is not the case in arid desert-like regions, where limited nesting options frequently force diverse owls to use rocky areas as nesting sites.[3][112] However, the cliffs and other rocky areas preferred by Eurasian eagle-owls are also utilized by several species of diurnal raptor in Eurasia. In Spain, golden eagles, Bonelli's eagles and peregrine falcons (Falco peregrinus) most often nest on cliffs. Large scavenging birds such as cinereous vultures (Aegypius monachus), bearded vultures (Gypaetus barbatus), Eurasian griffons (Gyps fulvus), Egyptian vulture (Neophron percnopterus) and common ravens also often nests on the same Iberian cliffs. While the two eagles nested at great distances from one another (they are known to be territorial towards each other), the eagle-owl nesting within 2 to 3km (1.2 to 1.9mi) of the other species. In these cliff nests, the only considerable predatory interaction was the eagle-owls appearing to predate the peregrine falcons.[134] In the Tibetan Plateau, upland buzzards (Buteo hemilasius) also seem to favor similar habitats and both the eagle-owl and buzzard take similar prey there.[50] In general, the eagle-owl can nest closer to diurnal raptors because, as a nocturnal animal, it will not actively compete for territories as it would with other members of its own species.[2] European herring gull
The herring gull doesn't need swimming, but seems to enjoy all kind of waters, especially on hot summer days. The herring gull can only catch slow creatures, like small crabs, which they often drop from some altitude in order to get them opened. The birds haven't got any real power in its jaws while biting, but it may "pick" with better strength. Fish on land, eggs of other birds, and helpless chicks of smaller ducks (and similar birds where the female is the only caretaker of up to 9 eggs and chicks) are about as much predator the bird gets. It's then far more successful as a scavenger. Like vultures, adult birds can dig their whole head and neck into for instance a dead rabbit. Although not always appreciated by mankind due to their dropping and screaming, the herring gull must be regarded as a "natural cleaner", and just as with crow-birds they help by keeping rats away from the surface in urban environment. Not by killing rats but by eating the potential rat food before the rats get the chance. Unlike real scavengers, herring gulls also eat most kind of other things than meat, like wasted food of all kind, from bread to human vomit. They seldom eat fresh fruit, but windfalls and rotten fruit seems more tasteful.] Balkan lynx
The Lynx genus usually hunts lagomorphs, or hares and rabbits. However, the Eurasian lynx also hunts small ungulates, or deer such as roe deer, chamois, or musk deer. Although the lynx is known to have killed up to 30% of the roe deer population in northern Europe, they are not usually considered a threat to livestock. However, in Norway, lynxes have killed increasing numbers of sheep, up to 10,000 between 1996 and 2001. Eurasian eagle-owl
Electrocution was the greatest cause of mortality in 68% of 25 published studies and accounted, on average, for 38.2% of the reported eagle-owl deaths. This was particularly true in the Italian Alps, where the number of dangerous, non-insulated pylons near nests was extremely high, but is highly problematic almost throughout the species’ European distribution.[88][89] In one telemetry study, 55% of 27 dispersing young were electrocuted within 1 year of their release from captivity, while electrocution rates of wild-born young are even higher.[90][91] Mortality in the Swiss Rhine Valley was variable, in radio-tagged, released individuals, most died as a result of starvation (48%) rather than human-based causes but 93% of the wild, un-tagged individuals found dead were due to human activities, 46% due to electrocution and 43% due to collision with vehicles or trains. It was concluded there that insulation of pylons would result in a stabilisation of the local population due to floaters taking up residence in non-occupied territories that formerly held deceased eagle-owls.[92] Eurasian eagle-owls from Finland were found mainly to die due to electrocution (39%) and collisions with vehicles (22%).[93] Wind turbine collisions can also be a serious cause of mortality locally.[94] Eurasian eagle-owl
Description, photos and calls Eurasian eagle-owl
The eagle-owl can live for up to 20 years in the wild. At one time the oldest ringed eagle-owl was considered a 19-year-old specimen.[14] Another banded specimen was subsequently found to be 27 years and 9 months old.[4] Like many other bird species in captivity they can live much longer without having to endure difficult natural conditions, and have possibly survived up to 68 years in zoo collections.[4] Healthy adults normally have no natural predators and are thus considered apex predators. The leading causes of death for this species are man-made: electrocution, traffic accidents and shooting frequently claim the life of eagle-owls.[14][17] Eurasian pygmy owl
The Eurasian pygmy owl is usually red-tinged to a greyish-brown with dots on its back. The tail is generally darker than the body with five narrow, whitish bars. It has a small, short head with white to grey eyebrows and yellow eyes. It lacks the ear tufts that many other owls have. There is a white half collar on the back of the neck. The belly is mostly white with brown speckles. The beak is a greyish yellow and hook-shaped. European rabbit
The European rabbit ("Oryctolagus cuniculus") or coney is a species of rabbit native to southwestern Europe (including Spain, Portugal and western France) and to northwest Africa (including Morocco and Algeria). It has been widely introduced elsewhere, often with devastating effects on local biodiversity. However, its decline in its native range (caused by the diseases myxomatosis and rabbit calicivirus, as well as overhunting and habitat loss), has caused the decline of its highly dependent predators, the Iberian lynx and the Spanish imperial eagle. It is known as an invasive species because it has been introduced to countries on all continents with the exception of Antarctica, and has caused many problems within the environment and ecosystems. Feral European rabbits in Australia have had a devastating impact, due in part to the lack of natural predators there. Eurasian eagle-owl
B. b. interpositus (Rothschild and Hartert, 1910)- May be known as Aharoni’s eagle-owl or the Byzantine eagle-owl.[44][45] B. b. interpositus ranges from southern Russia, south of the nominate, with which it intergrades in northern Ukraine, from Bessarabia and the steppes of the Ukraine north to Kiev and Kharkov then eastward to the Crimea, the Caucasus and Transcaucasia to northwestern and northern Iran (Elburz, region of Tehran, and probably the southern Caspian districts), and through Asia Minor south to Syria and Iraq but not to the Syrian desert where it is replaced by the pharaoh eagle-owl. The latter and B. b. interpositus reportedly hybridize from western Syria south to southern Palestine.[33][35] B. b. interpositus may be a distinct species from the Eurasian eagle-owl based on genetic studies.[7][14] This medium-sized subspecies is about the same size as the nominate subspecies B. b. bubo, with male wing chord lengths 425 to 475mm (16.7 to 18.7in) and female lengths of 440 to 503mm (17.3 to 19.8in).[7][35] It differs from the nominate subspecies by being paler and more yellow, less ferruginous, and by having a sharper brown pattern; from B. b. turcomanus by being very much darker and less yellow, and also by being much more sharply and heavily patterned with brown. Aharoni’s eagle-owl is darker and more rusty than B. b. ruthenus.[33][34] B. b. sibiricus (Gloger, 1833)- The western Siberian eagle-owl.[46] This subspecies is distributed from the Ural Mountains of western Siberia and Bashkiria to the mid Ob River and the western Altai Mountains, north to limits of the taiga, the most northerly distribution known in the species overall.[33] B. b. sibiricus is a large subspecies, wherein the males measure 435–480mm (17.1–18.9in) in wing chord length, while the females are 472–515mm (18.6–20.3in).[6][7][35] Captive males were found to measure 155 to 170cm (5ft 1in to 5ft 7in) in wingspan and weigh 1.62 to 3.2kg (3.6 to 7.1lb); whereas the females measure 165 to 190cm (5ft 5in to 6ft 3in) in wingspan and weigh 2.28 to 4.5kg (5.0 to 9.9lb).[36] Males were cited with a mean body mass of approximately 2.5kg (5.5lb).[47] This subspecies is physically the most distinctive of all the Eurasian eagle-owls, and is sometimes considered the most "beautiful and striking".[33] It is the most pale of the eagle-owl subspecies; the general coloration is a buffy off-white overlaid with dark markings. The crown, hindneck and underparts are streaked blackish but somewhat sparingly, with the lower breast and belly indistinctly barred, the primary coverts dark, contrasting with rest of the wing. The head, back and shoulders are only somewhat dark unlike in most other subspecies. In the eastern limits of its range, B. b. sibiricus may intergrade with B. b. yenisseensis.[14][33] B. b. yenisseensis (Buturlin, 1911)- Known as the eastern Siberian eagle-owl.[48] This subspecies is found in central Siberia from about the Ob eastward to Lake Baikal, north to about latitudes 580 to 590 N on the Yenisei River, south to the Altai, Tarbagatai and the Saur Mountain ranges and in Tannu Tuva and Khangai Mountains in northwestern Mongolia, grading into B. b. sibiricus near Tomsk in the west and into B. b. ussuriensis in the east of northern Mongolia. The zone of intergradations with the latter in Mongolia seems to be quite extensive, with intermediate eagle-owls being especially prevalent around the Tuul River Valley, resulting in owls intermediate in coloration between B. b. yenisseensis and B. b. ussuriensis.[33][34] B. b. yenisseensis is a large subspecies, with wing chord lengths of 435–470mm (17.1–18.5in) in males and 473–518mm (18.6–20.4in) in females.[7][35] B. b. yenisseensis is typically much darker with more yellowish ground colour than B. b. sibiricus. It does have a similar amount of dazzling white on its underwing as does sibiricus.[4] It is buffy-greyish overall with well-expressed dark patterning on the upper-parts and around the head. The underside is overall pale greyish with black streaking.[33] B. b. jakutensis (Buturlin, 1908)- May be called the Yakutian eagle-owl. This subspecies inhabits northeastern Siberia, from southern Yakutia north to about latitude 640 N., west in the basin of the Vilyuy River to the upper Nizhnyaya Tunguska River, and east to the coast of the Sea of Okhotsk from Magadan south to the Khabarovsk Krai. It has been reported farther north, from the regions of the upper Kolyma River and the upper Anadyr. Eurasian eagle-owls are absent in Kamchatka and north of the Verkhoyansk Range.[33] This is a large subspecies, rivaling the proceeding two subspecies as the largest of all eagle-owls, going on wing chord length, which subspecies is largest is unclear considering the extensive size overlap in wing size. The wing chord is 455 to 490mm (17.9 to 19.3in) in males and 480 to 503mm (18.9 to 19.8in) in females.[7][14][35] B. b. jakutensis is much darker and browner above than both B. b. sibiricus and B. b. yenisseensis, though its coloration is more diffused, less sharp than the latter. It is more distinctly streaked and barred below than B. b. sibiricus while being whiter and more heavily vermiculated below than B. b. yenisseensis.[33][34] B. b. ussuriensis (Poljakov, 1915) – Would presumably be referred to as the Ussuri eagle-owl. This subspecies ranges from southeastern Siberia, to the south of the range of B. b. jakutensis, southward through eastern Transbaikal, Amurland, Sakhalin, Ussuriland and the Manchurian portion of the Chinese provinces of Shaanxi, Shanxi and Hebei.[33][34] This subspecies is also reportedly found in the southern Kuril Islands ranging down to as far as northern Hokkaido, the only Japanese representation in the Eurasian eagle-owl species, although this is apparently not a stable, viable population.[49] Going on wing chord length, B. b. ussuriensis is slightly smaller than the various subspecies from further north in Siberia. Males have a wing chord length of 430–475mm (16.9–18.7in) and females are 460–502mm (18.1–19.8in).[7][33][35] This subspecies differs from B. b. jakutensis by being much darker throughout. It is also darker than B. b. yenisseensis. The brown markings on the upper parts of B. b. ussuriensis are much more extensive and diffused than in B. b. jakutensis or B. b. yenisseensis, with the result that the white markings are much less conspicuous in B. b. ussuriensis than in the other two subspecies. The under parts are also more buffy, much less white, and more heavily streaked and vermiculated in B. b. ussuriensis than in the two more northerly, larger subspecies.[33] It overlaps considerably with jakutensis and some birds are of an intermediate appearance.[49] B. b. turcomanus (Eversmann, 1835)- This subspecies is known as the steppe eagle-owl.[50] It is distributed from Kazakhstan between the Volga and upper Ural Rivers, the Caspian Sea coast and the former Aral Sea, but replaced in that country by B. b. omissus in the mountainous south and in the coastal region of the Mangyshlak Peninsula by B. b. gladkovi. Out of Kazakhstan, the range of B. b. turcomanus continues through the Transbaikal and the Tarim Basin to western Mongolia.[33][34] This subspecies appears to be variable in size, but is generally medium-sized. Males can range in wing chord length from 418–468mm (16.5–18.4in) and females from 440 to 512mm (17.3 to 20.2in).[7][35] In standard measurements, the tail is 260–310mm (10–12in), the tarsus is 77–81mm (3.0–3.2in) and the bill is 45–47mm (1.8–1.9in).[7] This subspecies can reportedly weigh from 1.5 to 3.8kg (3.3 to 8.4lb).[51] The plumage background colour is pale, yellowish-buff. The dark patterns on the upper- and underparts is paler, less well-defined and more shattered than in B. b. interpositus. Dark longitudinal patterning on the under-parts discontinue above the belly. B. b. turcomanus is greyer than B. b. hemalachanus but is otherwise somewhat similar-looking. This subspecies is unique in that it seems to shun mountainous and obvious rocky habitats in favor of low hills, plateaus, lowlands, steppes, and semideserts at or near sea-level.[33] B. b. omissus (Dementiev, 1932) – May be called the Turkoman eagle-owl or the Turkmenian eagle-owl.[52][53] B. b. omissus is native to Turkmenistan and adjacent regions of northeastern Iran and western Xinjiang.[33][34] This is a small subspecies (only nikolskii averages smaller among currently accepted races), with males possessing a wing chord length of 404–450mm (15.9–17.7in) and females of 425 to 460mm (16.7 to 18.1in).[7][35] B. b. omissus may be considered a typical sub-desert form. The general coloration is an ochre to buffy off-yellow; with the dark pattern on the upper- and under-parts being relatively undefined. The dark shaft-streaks on nape are very narrow, while the dark longitudinal patterning on the underparts does not cover the belly. A dark cross-pattern on the belly and flanks is thinner and paler than in B. b. turcomanus. Compared to B. b. nikolskii, which may occupy the more southern reaches of the same upland ranges, it is somewhat larger as well as darker, less distinctly yellowish and more heavily streaked.[33] B. b. nikolskii (Zarudny, 1905) – May be referred to in English either the Afghan eagle-owl or the Iranian eagle-owl.[54][55] The range of B. b. nikolskii appears to extend from the Balkan Mountains and Kopet Dagh in southern Transcaspia eastward to southeastern Uzbekistan or to perhaps southwestern Tadzhikistan, then southward 290 N. It may range north to Iran, Afghanistan and Baluchistan south to the region of Kalat, or at about latitude of Hindu Kush. In Iran, B. b. nikolskii is replaced by B. b. interpositus in the north, and probably also in the northwest, and probably by B. b. hemalachana in Badakhshan, part of northeastern Afghanistan. The birds of southern Tadzhikistan found west of the Pamirs are more or less intermediate between B. b. omissus and B. b. hemachalana.[33] This is the smallest known subspecies of eagle-owl, though the only known measurements have been of wing chord length. Males can measure 378 to 430mm (14.9 to 16.9in) and females can measure 410 to 465mm (16.1 to 18.3in) in wing chord.[6][7][35] Other than its smaller size, B. b. nikolskii is distinguished from the somewhat similar B. b. omissus by its rusty wash and being less dark above.[33][34] B. b. hemachalana (Hume, 1873) – The Himalayan eagle-owl.[56] The range of B. b. hemachalana extends from the Himalayas and Tibet, westward to the Tian Shan system in Russian Turkestan, west to the Kara Tau, north to the Dzungarian Alatau, east to at least the Tekkes Valley in Xinjiang, and south to the regions of Kashgar, Yarkant and probably the western Kunlun Mountains. This bird is partly migratory, descending to the plains of Turkmenistan with colder winter weather, and apparently reaches northern Balochistan.[33] This is a medium-sized subspecies, though is larger than other potentially abutting arid Asian eagle-owl subspecies which share a somewhat similar yellowish ground colour. The male attains a wing chord length of 420–485mm (16.5–19.1in), while the female’s wing chord is 450–505mm (17.7–19.9in).[7][35] The bill measures 42–45mm (1.7–1.8in) in length. 11 adult eagle-owls of subspecies race from the Tibetan Plateau averaged 301mm (11.9in) in tail length, 78mm (3.1in) in tarsus length and scaled an average of 2.16kg (4.8lb) in mass.[57] This subspecies is physically similar to B. b. turcomanus but the background colour is more light yellowish-brown and less buff. The dark patterns on upper- and under-parts are some more expressed and less regular than in B. b. turcomanus and B. b. omissus and the general colour from the mantle to the ear tufts is a more consistent brownish colour than most other abutting races. B. b. hemachalana differs from B. b. yenisseensis by being much more yellow on the rump, under tail coverts, and outer tail feathers, rather than grayish or whitish, and the ground coloration of its body is more yellowish above, and is less whitish below. Dark longitudinal pattern on the under-parts cover the fore-belly.[35] B. b. kiautschensis (Reichenow, 1903) – This could be called the north Chinese eagle-owl. This race ranges from South Korea and China, south of the range of B. b. ussuriensis, southward to Kwangtung and Yunnan, and inland to Szechwan and southern Kansu.[33] This is a smallish subspecies, with the male’s wing chord measuring 410–448mm (16.1–17.6in) and the female’s being 440–485mm (17.3–19.1in).[7][35] In Korea, this subspecies was found to average 2.26kg (5.0lb) in mass, with a range of 1.8 to 2.9kg (4.0 to 6.4lb).[58] B. b. kiautschensis is much darker, more tawny and rufous, and slightly smaller than B. b. ussuriensis. It resembles the nominate subspecies from Europe (though obviously considerably disparate in distribution) rather closely in coloration but differs from it by being paler, more mottled, and less heavily marked with brown on the upper parts, by having narrower dark shaft streaks on the under parts, which average also duller and more ocher, and by averaging smaller.[33] B. b. swinhoei (Hartert, 1913) – This could be called the south Chinese eagle-owl. This subspecies is endemic to southeastern China. A quite rufescent form, it is somewhat similar to B. b. kiautschensis. In this small subspecies, the wing chord measures 410–465mm (16.1–18.3in) in both sexes. This is a rather poorly known and described subspecies and is considered invalid by some authorities.[6][7][33] Tawny eagle
The tawny eagle's diet is largely fresh carrion of all kinds, but it kills small mammals up to the size of a rabbit, reptiles, and birds up to the size of guineafowl. It also steals food from other raptors. Verreaux's eagle-owl
So far as is known, Verreaux's eagle-owl is the only living owl who predates multiple species of primate, although isolated incidents of predation (normally on young primates) has been reported in two to three other large, tropical owls. Multiple cases of predation against galagos have been reported, unsurprisingly as they represent all nocturnal primates in Africa, although they are seldom identified to species. Known galago prey species have ranged from the Thomas's bushbaby ("Galagoides thomasi") to the brown greater galago ("Otolemur crassicaudatus"). Monkeys are also predated opportunistically. Particularly often reported in foods of the Verreaux's eagle-owl as primates go is the vervet monkey ("Chlorocebus pygerythrus"). Incidents of successful predation have included vervets that were half-grown, which the eagle-owl was able to fly off with (despite being about as heavy as the eagle-owl itself), and an adult vervet of an estimated weight of , which an eagle-owl took on the ground and subsequently dismembered. However, considering the formidable gauntlet of predators that vervet monkeys face, the Verreaux's eagle-owl is one of its more minor predators and attacks on them may be considered incidental, due in part to the monkey's primarily diurnal activities. Other monkey species believed to be occasionally vulnerable to attacks include the blue monkey ("Cercopithecus mitis"), which is similar in size to the vervet, patas monkeys ("Erythrocebus patas") and the young of the chacma baboon ("Papio ursinus"). Adult patas monkeys, averaging some , can be even larger than vervet monkeys but whether they take prime adults of the species is questionable. There are a few verified cases of Verreaux's eagle-owls feeding on ungulates, however some authors such as Avery, et al. (1985) feel that these generally represent cases of scavenging on carrion. The remains of an adult grysbok ("Raphicerus melanotis"), weighing an estimated , was opined with certainty to have been taken as carrion per this study. However, Steyn (1982) accepted that this species could take live prey weighing up to on rare occasions, however he stated in a case of an adult common duiker ("Sylvicapra grimmia") being fed on by an eagle-owl that the duiker was likely roadkill. Scavenging on carrion is generally a rare behaviour in owls and has been reported in only a few cases where large owls are exceptionally hungry. Live ungulates verified to have been hunted have included piglets of common warthogs ("Phacochoerus africanus"), which have an average birth weight of only but grow to over in just a couple weeks. Adult Kirk's dik-diks ("Madoqua kirkii"), one of the smallest antelope species at an average of have also been hunted by Verreaux's eagle-owl. Eurasian tree sparrow
Predators of the tree sparrow include a variety of accipiters, falcons and owls, such as the Eurasian sparrowhawk, common kestrel, little owl, and sometimes long-eared owl and white stork. It does not appear to be at an increased risk of predation during its autumn moult, despite having fewer flight feathers at that time. Nests may be raided by Eurasian magpies, jays, least weasels, rats, cats and constricting snakes such as the horseshoe whip snake. Eurasian eagle-owl
While the eagle-owl remains reasonably numerous in some parts of its habitat where nature is still relatively little disturbed by human activity, such as the sparsely populated regions of Russia and Scandinavia, concern has been expressed about the future of the Eurasian eagle-owl in western and central Europe. There, very few areas are not heavily modified by human civilisation, thus exposing the birds to the risk of collisions with deadly man-made objects (e.g. pylons) and a depletion of native prey numbers due to ongoing habitat degradation and urbanisation.[5][6] European rabbit
The European rabbit is prey to many different predatory species. Foxes, dingoes, wolves, lynxes, wolverines and dogs kill both adult and young rabbits by stalking and surprising them in the open. However, relatively few rabbits are caught this way, as rabbits can quickly rush back to cover with a burst of speed. Further, evidence from a study in Spain suggests they may avoid areas where the recent scat of predators which have eaten rabbit is detected. Both foxes and badgers will dig out kittens from shallow burrows, with the latter predators being too slow to catch adult rabbits. Both wild and domestic cats will stalk and leap upon rabbits, particularly young specimens leaving their burrows for the first time. Wildcats take rabbits according to availability: in eastern Scotland, where rabbits are abundant, they can comprise over 90% of the wildcats' diet. Most domestic cats are incapable of killing healthy, full-grown adults, but will take weak and diseased ones. Does can be fiercely protective of their kittens, having been observed to chase away large cats and mustelids, including ferrets, stoats and weasels. However, rabbits typically run from mustelids, and may fear them innately. Cases are known of rabbits becoming paralysed with fear and dying when pursued by stoats or weasels, even when rescued unharmed. It is known that the European rabbit comprises 85% of the polecat's diet, and its availability is important to the success of breeding female mink. Brown rats can be a serious threat to kittens, as they will reside in rabbit burrows during the summer, and attack them in groups. Although many birds of prey are capable of killing rabbits, few are strong enough to carry them. Large species, such as golden and sea eagles, may carry rabbits back to their nests, while small eagles, buzzards and harriers struggle to do so. Hawks and owls typically only carry off very small kittens. Eurasian sparrowhawk
Male Eurasian sparrowhawks regularly kill birds weighing up to and sometimes up to ; females can tackle prey up to or more. The weight of food consumed by adult birds daily is estimated to be for males and for females. During one year, a pair of Eurasian sparrowhawks could take 2,200 house sparrows, 600 common blackbirds or 110 wood pigeons. Species that feed in the open, far from cover, or are conspicuous by their behaviour or coloration, are taken more often by Eurasian sparrowhawks. For example, great tits and house sparrows are vulnerable to attack. Eurasian sparrowhawks may account for more than 50% of deaths in certain species, but the extent varies from area to area. Eurasian wolf
Many Eurasian wolf populations are forced to subsist largely on livestock and garbage in areas with dense human activity, though wild ungulates such as moose, red deer, roe deer and wild boar are still the most important food sources in Russia and the more mountainous regions of Eastern Europe. Other prey species include reindeer, argali, mouflon, wisent, saiga, ibex, chamois, wild goats, fallow deer and musk deer. Eurasian eagle-owl
Even those near the northern limits of their range, where winters are harsh and likely to bear little in food, the eagle-owl does not leave its native range. There are cases from Russia of Eurasian eagle-owls moving south for the winter, as the icebound, infamously harsh climate there is too severe even for these hardy birds and their prey. Similarly, Eurasian eagle-owls living in the Tibetan highlands and Himalayas may in some cases vacate their normal territories when winter hits and move south. Even in those two examples, there is no evidence of consistent, annual migration by Eurasian eagle-owls and the birds may eke out a living on their normal territories even in the sparsest times.[5][6] Dietary biology of the Eurasian eagle-owl
Other than these two species, a large share of the raptorial prey for eagle-owls is made up of other owls. Given that all European owls are to some extent nocturnal, they may be encountered and killed upon detection by the Eurasian eagle-owl. In Europe, it has killed every other species of owl, from the tiny pygmy owl and scops owl to the large 1,078g (2.377lb) great grey owl and the 2,040g (4.50lb) snowy owl.[126] The Eurasian eagle-owl is the only raptor that has been known to prey on snowy owl on multiple occasions.[95][112][126] However, the threat Eurasian eagle-owls poses to other raptors can be exaggerated.[129] Occasionally, with adequate mammal prey populations, they can nest as close as a few dozen meters of other raptors and never harass them.[112] When nesting in the same groves as the 1,175g (2.590lb) long-legged buzzards (Buteo rufinus) in southeastern Bulgaria, Eurasian eagle-owls did not predate the buzzards at any point.[95][130] Long-legged buzzards have been killed however in Kazakhstan.[77] Even in those occasional cases where they pick off one or several raptors, they do not effect the overall population, unless the raptorial prey is already heavily diminished due to some other (often human-based) cause. For example, despite both being a known predator of both, they did not significantly depress numbers of either northern goshawks or tawny owls in southern Finland.[129] One study showed that many raptors engage in spatial avoidance during potential encounters with Eurasian eagle-owls and while the predation by eagle-owls did decrease raptor population densities, they seldom caused declines in breeding success or altered habitat occupancy.[131] Brown bear
In some areas, the grizzly bear also regularly displaces cougars ("Puma concolor") from their kills, with some estimates showing cougars locally lose up to a third of their dietary energy to grizzly bears. Cougars kill small bear cubs on rare occasions, but there was one report of a bear killing a cougar of unknown age and condition between 1993 and 1996. Eurasian lynx ("Lynx lynx"), the largest type of lynx and the only one to regularly take large prey, is similarly an habitual victim of kleptoparasitism to brown bears throughout Eurasia. Brown bears also co-exist with leopards ("Panthera pardus") (in very small remnant wild parts of the Middle East, Jammu and Kashmir, northeastern China and the Primorsky Krai) and snow leopards ("Panthera uncia") in several areas of northern central Asia and the Tibetan Plateau). Although the brown bears' interactions with these big cats are little known, they probably have similar relationships as grizzly bears do with cougars in North America. Snow leopards and Tibetan blue bears are verified, however, to be a threat to one another's cubs. Eurasian eagle-owl
As a highly opportunistic predator, the Eurasian eagle-owl will hunt almost any appropriately sized prey they encounter. Most often they take what ever prey is locally common and can take a large number of species considered harmful to human financial interests such as rats, mice and pigeons. Eurasian eagle-owls do take rare or endangered species as well. Among the species considered at least vulnerable (up to critically endangered as in the mink and eel, both heavily overexploited by humans) to extinction known to be hunted by Eurasian eagle-owls are Russian desman (Desmana moschata)[108] Pyrenean desman (Galemys pyrenaicus),[109] barbastelle (Barbastella barbastellus),[110] European ground squirrel (Spermophilus citellus),[111] southwestern water vole (Arvicola sapidus),[112] European mink (Mustela lutreola),[113] marbled polecat (Vormela peregusna),[108] lesser white-fronted goose (Anser erythrops),[114] Egyptian vulture (Neophron percnopterus),[115] greater spotted eagle (Clanga clanga),[116] eastern imperial eagle (Aquila heliaca),[116] saker falcon (Falco cherrug),[117] houbara bustard (Chlamydotis undulata),[108] great bustard (Otis tarda),[114] spur-thighed tortoise (Testudo graeca),[118] Atlantic cod (Gadus morhua),[119] European eel (Anguilla anguilla)[119] and lumpfish (Cyclopterus lumpus).[119] Ural owl
The northern populations of the Ural owl occupy similar habitat to the great grey owl, nesting in lowland forests but avoiding dense areas, especially those of purely conifers. In central Europe it is an upland species, preferring deciduous woodland. It usually occupies open woodland and is more often found in moist rather than dry areas. It nests in hollow tree trunks, occasionally in old raptor nests, and increasingly in nestboxes. It normally lays two to four eggs, which hatch after 27–34 days. The young leave the nest after about four weeks, but will not fly until about six weeks old. It is a very aggressive owl, chasing other birds of prey from its territory, and it will attack human intruders, especially when young are present. Dietary biology of the Eurasian eagle-owl
The diet is generally more diverse than any other co-existing owl but often focuses predominantly on a particular range of prey species, with two to four species often making up the majority of the diet.[15] Studies conducted over the course of years has shown that the regional diet often changes dramatically from year to year. This is partially driven by the cyclical population trends of much of their prey as well as by habitat changes, which are often due to human activities.[2][15] The primary prey species varies by region but is comprised mainly by small mammals such as voles, rats, mice, rabbits and hares.[3] In Europe, the five main prey species are, in order of extent of reporting and numeric abundance in dietary studies: the brown rat (Rattus norvegius), which has now occupied edge habitats (although generally associated with man) in almost every part of Europe excluding the colder north; the common vole (Microtus arvalis), often the most abundant native, small mammal in wild portions of Europe;[16] the European hedgehog (Erinaceus concolor), which occupies wooded edges across western Europe alongside the eagle-owls; the European water vole (Arvicola amphibius), a unique, large vole occupying the wetland edges often hunted by eagle-owls; and the European rabbit (Oryctolagus cuniculus), which has a very close relationship with the eagle-owls found throughout the Iberian Peninsula and the massifs of France.[2][17][18] As the distribution of the Eurasian eagle-owls moves west (and south), the primarily prey species gradually change but often continues to be dominated in number by small rodents and in biomass by slightly larger mammals such as hedgehogs and hares and rabbits.[2][18] Great tit
The Eurasian sparrowhawk is a predator of great tits, with the young from second broods being at higher risk partly because of the hawk's greater need for food for its own developing young. The nests of great tits are raided by great spotted woodpeckers, particularly when nesting in certain types of nest boxes. Other nest predators include introduced grey squirrels (in Britain) and least weasels, which are able to take nesting adults as well. A species of biting louse (Mallophaga) described as "Rostrinirmus hudeci" was isolated and described in 1981 from great tits in central Europe. The hen flea "Ceratophyllus gallinae" is exceedingly common in the nests of blue and great tits. It was originally a specialist tit flea, but the dry, crowded conditions of chicken runs enabled it to flourish with its new host. This flea is preferentially predated by the clown beetle "Gnathoncus punctulatus", The rove beetle "Microglotta pulla" also feeds on fleas and their larvae. Although these beetles often remain in deserted nests, they can only breed in the elevated temperatures produced by brooding birds, tits being the preferred hosts. Great tits compete with pied flycatchers for nesting boxes, and can kill prospecting flycatcher males. Incidences of fatal competition are more frequent when nesting times overlap, and climate change has led to greater synchrony of nesting between the two species and flycatcher deaths. Having killed the flycatchers, the great tits may consume their brains. Dietary biology of the Eurasian eagle-owl
Hedgehogs often comprise a fairly significant portion of the prey taken by Eurasian eagle-owls, both in numbers and biomass. At least eight species of hedgehog have been predated. The European hedgehog is often one of the most prominent prey species in eagle-owl diet studies from Europe, and was recorded as the most numerous prey species per researchers in parts of Denmark, Switzerland, Austria and south Germany. With an average weight of 500 to 1,000g (1.1 to 2.2lb), the European hedgehog can comprise a very large portion of the biomass.[18][27][57][72] A study of the Bavarian region of Germany, the European hedgehog (the main prey species) made up 41.7% of the prey by number and 52.1% of the biomass, the maximum representation of hedgehogs known in Europe.[73] Other members of the Erinaceus genus are also locally regularly taken, as is the 575g (1.268lb) Daurian hedgehog (Mesechinus dauuricus) in Mongolia.[51] Studies from Greece and the Czech Republic found that the northern white-breasted hedgehog (Erinaceus roumanicus) was the leading prey species.[74][75] Unidentified Erinaceus hedgehogs almost totally dominated the diet of eagle-owls in Stavropol, Russia, making up 70.9% of the food, only the European rabbit has been found as more significant at the genera level by number in a given dietary study.[76] Studies from both Syria and Kazakhstan showed that the 365g (12.9oz) long-eared hedgehog (Hemiechinus auritus) was the most significant prey, making up 25.3% and 33.6% of the prey remains, respectively.[48][77] After killing hedgehogs, the Eurasian eagle-owls peel the prickly skin off their backs before consumption, frequently resulting in up to dozens of hedgehog backs being found around nests.[3][48][58] Moles and shrews are readily hunted but are usually only a secondary portion of the diet. Eurasian eagle-owls have been recorded hunting the smallest mammal on earth (by weight) the 1.8g (0.063oz) Etruscan shrew (Suncus etruscus), as well as the largest mole on earth, the 440g (16oz) Russian desman (Desmana moschata).[18][20] From the smallest shrew to the heaviest hedgehog, the Eurasian eagle-owl has been verified to hunt the full size range of insectivores. They've also attacked bats of every size available, from the smallest European bat, the 5.7g (0.20oz) common pipistrelle (Pipistrellus pipistrellus), to the largest species there, the 59g (2.1oz) greater noctule bat (Nyctalus lasiopterus). In the Sikhote-Alin range of the Russian Far East, bats were found to comprise 5.9% of the remains and, of five local owl species, the Eurasian eagle-owl was the most regular predator of bats in the area.[78] Siberian tiger
Siberian tigers also compete with the Eurasian lynx and may occasionally kill and eat them. Eurasian lynx remains have been found in the stomach contents of Siberian tigers in Russia. In March, 2014, a dead lynx was discovered in Bastak Nature Reserve by park workers of the Wildlife Conservation Society that bore evidence of predation by a Siberian tiger. The lynx had apparently been ambushed, pursued, and killed by the tiger but only partially consumed, which indicates that the tiger might have been more intent on eliminating a competitor than on catching prey. This incident marks one of the first documented cases of predation of a lynx by a tiger. Greater noctule bat
The most common predators of greater noctule bat are barn owl ("Tyto alba") and Eurasian eagle-owl ("Bubo bubo"). The greater noctule bat generally leaves its roost to forage after it is already completely dark outside, this coincides with the general time that the two mentioned owl species hunt. There is also some risk to the greater noctule from parasitism between bats.In Seville, Spain, one of the largest breeding colonies in Europe, the bats are in danger of obliteration. Rose-ringed parakeets, an invasive species, compete for homes in tree hollows, attacking and killing the bats. There has been an 81% decrease in trees inhabited by the bats since researchers first began keeping track. Eurasian eagle-owl
Long-eared owls in Eurasia have vertical striping like that of the Eurasian eagle-owl while long-eared owls in North America show a more horizontal striping like that of great horned owls. Whether these are examples of mimicry either way is unclear but it is known that both Bubo owls are serious predators of long-eared owls. The same discrepancy in underside streaking has also been noted in the Eurasian and American representations of the grey owl.[6] A few other related species overlap minimally in range in Asia, mainly in east Asia and the southern reaches of the Eurasian eagle-owl’s range. Three fish owls appear to overlap in range, the brown (Ketupa zeylonensis) in at least northern Pakistan, probably Kashmir and discontinuously in southern Turkey, the tawny (K. flavipes) through much of eastern China and the Blakiston's fish owl in the Russian Far East, northeastern China and Hokkaido. Fish owls are distinctively different looking, possessing more scraggy ear tufts that hang to the side rather than sit erect on top of the head, generally have more uniform, brownish plumages without the contrasting darker streaking of an eagle-owl. The brown fish owl has no feathering on the tarsus or feet and the tawny has feathering only on the upper portion of the tarsi but the Blakiston’s is nearly as extensively feathered on the tarsi and feet as the eagle-owl. Tawny and brown fish owls are both slightly smaller than co-occurring Eurasian eagle-owls and Blakiston’s fish owls are similar or slightly larger than co-occurring large northern eagle-owls. Fish owls, being tied to the edges of freshwater where they hunt mainly fish and crabs, also have slightly differing, and more narrow, habitat preferences.[4][14] Dietary biology of the Eurasian eagle-owl
Among coastal and some wetland areas, various water birds can come to contribute a large portion of both prey numbers and prey biomass. This may include more than 50 species of shorebird (from the one of the smallest sandpipers to the largest species of gull), more than 30 species of waterfowl, more than 10 species of herons, more than 8 species of rails and any grebes, cormorants or other water birds that are available.[2] The most regularly reported water bird prey in Europe were, roughly in this order, the 343g (12.1oz) common moorhens (Gallinula chloropus), the 836g (1.843lb) Eurasian coot (Fulica atra), 1,140g (2.51lb) mallards (Anas platyrhynchos), 284g (10.0oz) black-headed gull (Chroicocephalus ridibundus), and the 340g (12oz) Eurasian teal (Anas crecca).[2][95] The diet of a handful of eagle-owl pairs in the Riau Islands Province of France were found to be dominated by water birds, especially the 1,154g (2.544lb) yellow-legged gull (Larus michahellis), the colonial abundance of which allowed the eagle-owls to atypically occupy these small islands.[95][102] The diet of eagle-owls in Norway was dominated in coastal areas by water birds, overall for the nation 53% of the food was made of birds, the species most commonly identified as caught being the 388g (13.7oz) mew gull (Larus canus), 430g (15oz) common puffin (Fratercula arctica) and 2,070g (4.56lb) common eider (Somateria mollissima). Despite access to large seabird breeding colonies, almost all large bird species hunted in Norway, including large forest grouse in more inland areas, were apparently fully-grown adults and most water birds were caught while resting on open coastal waters.[14][95] Eagle-owls in northwestern Poland, an area heavily dotted with lakes, relied on birds for about 64% of the diet, more than half of which were water birds. The main prey species there was the Eurasian coot, at nearly 15% of the prey numbers.[18] In Primorsky Krai in Russia, 53.2% of the food for the eagle-owls were made up of birds, predominantly water birds with the primary prey species being the 260g (9.2oz) crested auklet (Aethia cristatella ) (26.9%).[95][103] In the Russian Far East, similarly, birds occupy up to 57.6% of the diet, a lion's share of which are water birds. In this study, the grey red-backed vole and reed vole (Microtus fortis) were the most numerous identified individual species but in some years the extremely large Japanese cormorant (Phalacrocorax capillatus), at 2,820g (6.22lb), were more numerous as prey than either vole.[83][95] Water birds were found to be even more important in the diet in Korea, as in wetland habitat, with birds in general comprising 68.9% by number and 85.3% by biomass there, but in adjacent upland areas birds were slightly secondary to mammals, which made up 38.7% by number and 64.7% by biomass, led by the brown rat.[69] In Korea, the mallard and the similar spot-billed duck (Anas poecilorhyncha) made up 38.1% of the biomass.[69] Other recorded bird species in the Eurasian eagle-owl's diet includes all type of birds found in their range, including bustards, sandgrouse, parrots, cuckoos, swifts, the 67g (2.4oz) hoopoe (Upupa epops), the 56.5g (1.99oz) European bee-eater (Merops apiaster), the 31g (1.1oz) common kingfisher (Alcedo atthis), the 146g (5.1oz) European roller (Coracias garrulus), at least seven species of woodpecker (from the smallest to the largest European species) and more than 80 species of passerine.[2][95] Among passerines, the only family reported widely as prey besides corvids are thrushes. In the Italian Alps, Turdus species were the fourth most frequently recorded type of prey.[30] In particular, the abundant 103g (3.6oz) Eurasian blackbird (Turdus merula) is widely reported to be taken by eagle-owls.[12][23][95] As thrushes are relatively small, at 55 to 130g (1.9 to 4.6oz) among the species known to be predated, pairs in the Italian Alps who depended more so on thrushes usually showed lower productivity during nesting attempts.[30] Common raven
Owing to its size, gregariousness and its defensive abilities, the common raven has few natural predators. Predators of its eggs include owls, martens, and sometimes eagles. Ravens are quite vigorous at defending their young and are usually successful at driving off perceived threats. They attack potential predators by flying at them and lunging with their large bills. Humans are occasionally attacked if they get close to a raven nest, though serious injuries are unlikely. There are a few records of predation by large birds of prey. Their attackers in America have reportedly included great horned owls, northern goshawks, bald eagles, golden eagles and red-tailed hawks, it is possible that the two hawks only have attacked young ravens, as had a peregrine falcon who in one instance swooped at a newly fledged raven but was successfully chased off by the parent ravens. In Eurasia, their reported predators include, in addition to golden eagles, Eurasian eagle-owls, white-tailed eagles, Steller's sea-eagles, eastern imperial eagles and gyrfalcons. Because they are potentially hazardous prey for raptorial birds, raptors must usually take them by surprise and most attacks are on fledgling ravens. More rarely still, large mammalian predators such as lynxes, coyotes and cougars have also attacked ravens. This principally occurs at a nest site and when other prey for the carnivores are scarce. Ravens are highly wary around novel carrion sites and, in North America, have been recorded waiting for the presence of American crows and blue jays before approaching to eat. Eurasian eagle-owl
Conversely to numerous threats and declines incurred by Eurasian eagle-owls, areas where human-dependent non-native prey species such as brown rats (Rattus norvegicus) and rock pigeons (Columba livia) have flourished, have given the eagle-owls a primary food source and allowed them occupy regions where they were once marginalized or absent.[60] Northern goshawk
Unlike the predators at the top of the avian food chain such as eagles and the largest owls, which are rarely endangered by predation as adults, the northern goshawk is itself susceptible to a fairly extensive range of predators. The most deadly are likely to be the Eurasian eagle owl and the great horned owl, which not only predate goshawks of any age and at any season but also opportunistically take over their own prior nests as their own nesting site. Of the two, the American horned owl nesting habits are more similar to goshawks, which most often consists of tree nests whereas the eagle owl usually nests in rock formations. Thus, the northern goshawk is more likely to victimized by the great horned owls, which can stage nightly ambushes and destroy an entire goshawk family as they pick off both adults and nestlings. In radio-tagging studies of adult and immature goshawks in the Great Lakes region and Arizona, up to half of the studied birds were killed by great horned owls at night, while the horned owls accounted for 40% of the nest failures in studies from Arizona and New Mexico. In comparison, in Schleswig-Holstein, 59% of reintroduced eagle owls used nests built by goshawks and no goshawk pairs could successfully nest within of an active eagle-owl nest. 18% of nest failures here positively were attributed to eagle owl predation, with another 8% likely due to eagle-owls. Other larger raptorial birds can threaten them. The golden eagle ("Aquila chrysaetos") and the bald eagle ("Haliaeetus leucocephalus") in North America, have killed wintering goshawks, but given the discrepancy in their habitat preferences, such cases are presumably rare. Other avian predators known to have successfully preyed on goshawks including adults (usually in singular cases) include white-tailed eagles ("Haliaeetus albicilla"), eastern imperial eagles ("Aquila heliaca"), snowy owls ("Bubo scandiacus") and red-tailed hawks. Eurasian blue tit
The small size of the Eurasian blue tit makes it vulnerable to prey by larger birds such as jays who catch the vulnerable fledglings when leaving the nest. The most important predator is probably the sparrowhawk, closely followed by the domestic cat. Nests may be robbed by mammals such as weasels and red squirrels, as well as introduced grey squirrels in the UK. White-tailed eagle
The white-tailed eagle ("Haliaeetus albicilla") is a very large eagle widely distributed across Eurasia. As are all eagles, it is a member of the family Accipitridae (or accipitrids) which includes other diurnal raptors such as hawks, kites, and harriers. One of up to eleven members in the genus "Haliaeetus", which are commonly called sea eagles, it is not infrequently also referred to as the white-tailed sea-eagle. It is also sometimes known as the ern or erne (depending on spelling by sources), gray sea eagle and Eurasian sea eagle While found across a very wide range, today breeding as far west as Greenland and Iceland across to as far east in Hokkaido, Japan, they are often scarce and very spottily distributed as a nesting species, mainly due to human activities. These have included habitat alterations and destruction of wetlands, about a hundred years of systematic persecution by humans (from the early 1800s to around World War II) followed by inadvertent poisonings and epidemics of nesting failures due to various manmade chemical pesticides and organic compounds, which have threatened eagles since roughly the 1950s and continue to be a potential concern. Due to this, the white-tailed eagle was considered endangered or extinct in several countries. However, some populations have recovered well due to some governmental protections and dedicated conservationists and naturalists protecting habitats and nesting sites and partially regulating poaching and pesticide usage, as well as careful reintroductions into parts of their former range. White-tailed eagles usually live most of the year near large bodies of open water, including both coastal saltwater areas and inland freshwater, and require an abundant food supply and old-growth trees or ample sea cliffs for nesting. They are considered a close cousin of the bald eagle ("Haliaeetus leucocephalus"), which occupies a similar niche in North America. Tyto robusta
It was found sympatrically with the gigantic relative, "Tyto gigantea", which at some 220% of the size of the barn owl grew to some 70–85 cm in length—larger than a Eurasian eagle-owl and maybe up to twice as heavy. Like other apex predators they can be presumed to have occurred at low population densities. Being apparently endemic to Gargano Island and perhaps some other islands in today's Apennines, where one or two huge eagles and at least at times a normal-sized barn-owl also occurred (though no large mammalian carnivores), these owls raise the question how minimum viable populations could be maintained long enough for them to live and prosper. Dietary biology of the Eurasian eagle-owl
A very large balance of the prey range can also be comprised by birds and other prey including reptiles, amphibians, fish, insects and other invertebrates are seemingly taken whenever they are available. All told, well more than 600 different species have been identified as prey of Eurasian eagle-owls.[2][17][18] Their diet includes basically all the same prey as all sympatric diurnal raptors in the genera Buteo, Aquila and Haliaeetus. The total number of prey species may even surpass that of the great horned owl and may well be the greatest of any raptorial bird on the Eurasian continent.[2] Among five segments of Europe the average prey diversity per region was 63 species, a higher number than any of the other 40 raptorial bird species studied there.[19] The mean mass of prey per study has varied from as little as 84.2g (2.97oz), near the now former Aral Sea in Turkmenistan with the Turkmen jerboa (Jaculus turkmenicus) being the primary prey species, to 1,037.9g (2.288lb), in Spain with the European rabbit being the primary prey species.[17][20] Remarkably, in northern Spain, where the rabbit is now extirpated (as was the eagle-owl for a time in the 20th century), the average weight of prey can dip as low as 87g (3.1oz).[21] In comparison, the lightest mean prey mass in dietary studies of the great horned owl was 22.5g (0.79oz) while the highest was 610.4g (1.346lb).[17][22] Dietary biology of the Eurasian eagle-owl
Throughout the western Mediterranean region, the Eurasian Eagle-Owl is something of a specialist on a single prey species: the European rabbit. The rabbit historically reached extremely high densities in Iberian scrub, i.e. more than 40 per every 1 square hectare (2471 square acres). In central Spain, up to 73.1% of the prey that were recorded for Eurasian eagle-owls, by number, can be rabbits.[20][60] Where still available, they are also the main prey in Portugal and central France.[61][62] However, following the devastation of the wild rabbit due to rabbit haemorrhagic disease, the local eagle-owls have frequently had to adapt to other, often smaller, prey. On the other hand, given the now much reduced numbers of rabbits, the eagle-owls still regularly select rabbits, seemingly out of proportion to their commonality.[63] Although large mature wild rabbits commonly weigh 1,700 to 2,400g (3.7 to 5.3lb), the eagle-owls usually hunt smaller specimens, often with an average weight around 1,000g (2.2lb), with young rabbits usually selected in spring and summer and subadults selected in the autumn and winter.[64] This is largely due to the behaviour of rabbits, with younger rabbits being forced to distribute following weaning, being less cautious in behaviour and occupying less primary habitat, thus being forced out of the confines of their burrows more regularly than mature adults.[64][65] However, the estimated average weight of rabbits taken can be variable, reported from as little as 800g (1.8lb) in a study from Spain to as much as 1,900g (4.2lb) in the Netherlands.[20][58] Dietary biology of the Eurasian eagle-owl
Three other lagomorphs extensively overlap in range with Eurasian eagle-owls in Europe, the mountain hare (Lepus timidus) in the northern portions, the European hare (Lepus europaeus) in the central and eastern portions and the Granada hare (Lepus granatensis) in the western Mediterranean portions. These species are all larger on average than a rabbit, averaging 2,000g (4.4lb) in the Granada hare, roughly twice that in the European hare and the mountain hare being intermediate between the two. Hares are often considerably secondary in prey remains in most European biomes by number but often are a significant contributor of prey biomass for eagle-owls. For example, in Finland, the mountain hare made up only 5.3% of prey by number but made up 56.2% of the prey biomass as the hare specimens were all large, with an estimated mean mass of 3,900g (8.6lb).[26] On the contrary, the mountain hare was the numerous prey species in one study from the Swiss Alps, making up 28.3% of the prey by number.[18] Another area near Europe where hares were numerically important was in southwestern Turkey, with the European hare being the second most common prey species by number. There it consisted of 18.1% of the quantity and presumably a huge portion of the biomass.[12] In lower Austria, the European hare was also the second most abundant species in the diet but the estimated average weight of hares taken was rather low, at 850g (1.87lb), indicating young hares of probably less than a month old are most often taken there.[57] On the other hand, in Slovenia, Netherlands and Bavaria, the European hares taken were estimated to average 2,500g (5.5lb), 4,500g (9.9lb) and 4,750g (10.47lb), respectively.[46][58][66] The European hare was also the second most common prey species in a study from the Czech Republic.[29] Eurasian sparrowhawk
Males tend to take tits, finches, sparrows and buntings; females often take thrushes and starlings. Larger quarry (such as doves and magpies) may not die immediately but succumb during feather plucking and eating. More than 120 bird species have been recorded as prey and individual Eurasian sparrowhawks may specialise in certain prey. The birds taken are usually adults or fledglings, though chicks in the nest and carrion are sometimes eaten. Small mammals, including bats, are sometimes caught but insects are eaten only very rarely.
Small birds are killed on impact or when squeezed by the Eurasian sparrowhawk's foot, especially the two long claws. Victims which struggle are "kneaded" by the hawk, using its talons to squeeze and stab. When dealing with large prey species which peck and flap, the hawk's long legs help. It stands on top of its prey to pluck and pull it apart. The feathers are plucked and usually the breast muscles are eaten first. The bones are left, but can be broken using the notch in the bill. Like other birds of prey, Eurasian sparrowhawks produce pellets containing indigestible parts of their prey. These range from long and wide and are round at one end and more narrow and pointed at the other. They are usually composed of small feathers, as the larger ones are plucked and not consumed. Raccoon dog
Both foxes and Eurasian badgers compete with raccoon dogs for food, and have been known to kill them if raccoon dogs enter their burrows. Eurasian lynxes rarely attack them. Birds of prey known to take raccoon dogs include golden eagles, white-tailed eagles, goshawks and eagle owls. Dietary biology of the Eurasian eagle-owl
In the northern extremes of their range, Eurasian eagle-owls tend to have a less varied diet than those to the south and the need to catch significant numbers of rodents rises as they are often the only regularly accessible prey in sparse sub-Arctic environments. In northern Sweden, more than 60% of the food was made up of microtine rodents, i.e. the 70g (2.5oz) Norway lemming (Lemmus lemmus), the field vole, the European water vole and the 36g (1.3oz) grey red-backed vole (Myodes rufocanus).[39] In one study from western Russia, rodents comprised more than 90% of the diet of the eagle-owls, led by the 25g (0.88oz) steppe lemming (Lagurus lagurus) at 24% by number, the 27g (0.95oz) narrow-headed vole (Microtus gregalis) at 21% and the European water vole at 17.9%.[40] Similarly in high altitude tundra of the East Austrian Alps, nearly 90% of the food was found to be comprised by microtine rodents, the 54g (1.9oz) European snow vole (Chionomys nivalis) being the most frequently identified species in the diet.[18] In Spain, the 19g (0.67oz) Algerian mouse (Mus spretus), at up to 41.8% of the prey by number, and 24g (0.85oz) wood mouse (Apodemus sylvaticus), at up to 10.5% by number, are often regularly taken, especially in regions where rabbit numbers have declined.[41][42] In Romania, the 98g (3.5oz) Romanian hamster (Mesocricetus newtoni) and 365g (12.9oz) European hamster are the most prominent species found in the eagle-owl's diet, alongside the brown rat.[31][43] The Romanian hamster is also dominated the prey list per a study in Bulgaria, only the European water vole follows distantly in number.[44] Dormice are readily taken when available in Europe, especially the 127g (4.5oz) edible dormouse from central Europe to the eastern countries.[45] In Slovenia, the edible dormouse was the most regularly-recorded prey species, making up 20.2% of the food but it comprised 9.4% of the biomass.[46] The edible dormouse was also the most regular prey species in Trentino-Alto Adige/Südtirol, Italy, making up 22.5% of the diet.[47] The smaller 82.5g (2.91oz) garden dormouse (Eliomys quercinus) and considerably smaller 27.3g (0.96oz) hazel dormouse (Muscardinus avellanarius) are also occasionally predated in Europe, plus at least a half dozen other dormouse species in eastern Europe, Asia Minor and several points to the east.[18] Wolf hunting
Wolf hunting historically gave rise to a vast vocabulary:Aerial shooting involves the tracking of wolves via a small airplane or helicopter and is considered by many to be the most effective method of wolf control. It was frequently used in the Soviet Union during its wolf control campaigns, starting in 1946 when the Chief Directorate of Aviation received reports that pilots flying at low altitudes frequently saw wolves. Polikarpov Po-2s and Antonov An-2s were the most frequently used models. The normal protocol was for the pilot to search frontally, and the shooter sideways. 70%-80% of wolves were first sighted by the pilot. Rocket guns would be fired into dense brush in order to scare wolves out into the open. Markers were thrown at the site of each kill for later collection. Actual shooting was done from the rear cockpit or left side when at a distance of 18–20 metres from the quarry. An experienced shooter could spot a standing wolf a kilometre away at heights of up to 100–140 metres. Most wolves were killed when the planes flew at speeds of 70 to 85 km/h. The load limit of a Po-2 was 2 men and 5 adult wolves; the rear cockpit could hold 4 wolves, while the shooter's cockpit could hold 2, or carcasses could be tied to the fuselage or wings of the plane. Aerial hunting has been discontinued in the former Soviet Union because of budget restraints. Wolf hunting is still practiced this way in the U.S state of Alaska. "Congress passed the Federal Airborne Hunting Act of 1972, which made it illegal for hunters to shoot animals from a plane or helicopter. The federal legislation does have a [provision] for predator control, permitting state employees or licensed individuals to shoot from an aircraft for the sake of protecting "land, water, wildlife, livestock, domesticated animals, human life, or crops". Least weasel
Despite its small size, the least weasel is a fierce hunter, capable of killing a rabbit five to ten times its own weight. Although they are commonly taken, the rabbits are usually young specimens, and become an important food source during the spring, when small rodents are scarce and rabbit kits are plentiful. Male least weasels take a higher proportion of rabbits than females, as well as an overall greater variety of prey. This is linked to the fact that being larger, and having vaster territorial ranges than females, males have more opportunities to hunt a greater diversity of prey. Southwick's Zoo
Eurasian Eagle-Owl Eurasian eagle-owl
Eagle-owls are distributed somewhat sparsely but can potentially inhabit a wide range of habitats, with a partiality for irregular topography.[59] They have been found in habitats as diverse as northern coniferous forests to the edge of vast deserts.[14] Essentially, Eurasian eagle-owls have been found living in almost every climatic and environmental condition on the Eurasian continent, excluding the greatest extremities, i.e. they are absent from humid rainforest in Southeast Asia, as well as the high Arctic tundra, both of which they are more or less replaced by other variety of Bubo owls.[6] They are often found in the largest numbers in areas where cliffs and ravines are surrounded by a scattering of trees and bushes. Grassland areas such as alpine meadows or desert-like steppe can also host them so long as they have the cover and protection of rocky areas.[60] The preference of eagle-owls for places with irregular topography has been reported in most known studies. The obvious benefit of such nesting locations is that both nests and daytime roosts located in rocky areas and/or steep slopes would be less accessible to predators, including man. Also, they may be attracted to the vicinity of riparian or wetlands areas, due to the fact that the soft soil of wet areas is conducive to burrowing by the small, terrestrial mammals normally preferred in the diet, such as voles and rabbits.[59] Due to their preference for rocky areas, the species is often found in mountainous areas and can be found up to elevations of 2,100m (6,900ft) in the Alps and 4,500m (14,800ft) in the Himalayas and 4,700m (15,400ft) in the adjacent Tibetan Plateau.[6][57][60] They can also be found living at sea-level and may nest amongst rocky sea cliffs.[6][14] Despite their success in areas such as sub-arctic zones and mountains that are frigid for much of the year, warmer conditions seem to result in more successful breeding attempts per studies in the Eifel region of Germany.[61] In a study from Spain, areas primarily consisting of woodlands (52% of study area being forested) were preferred with pine trees predominating the oaks in habitats used, as opposed to truly mixed pine-oak woodland. Pine and other coniferous stands are often preferred in great horned owls as well due to the constant density, which make it more likely to overlook the large birds.[6][59] In mountainous forest, they are not generally found in enclosed wooded areas, as is the tawny owl (Strix alucco).[6] Only 2.7% of the habitat included in the territorial ranges for eagle-owls per the habitat study in Spain consisted of cultivated or agricultural land.[59] On the other hand, compared to golden eagles, they can visit cultivated land more regularly in hunting forays due to their nocturnal habits, which allows them to largely evade human activity.[6] In the Italian Alps, it was found that almost no pristine habitat remained and locally eagle-owls nested in the vicinity of towns, villages and ski resorts.[60] Spot-bellied eagle-owl
This is a very powerful and bold predatory owl, which is assuredly at the top of the avian food chain in its forested range. However, no extensive study of its dietary habits is known. Even in larger eagle-owls such as the Eurasian eagle-owl, although they can and do prey on a wide range of prey including impressively large prey, most of the diet consists of small mammals, often small rodents such as voles and rats. There is no reason to assume that the spot-bellied eagle-owl does not also take a very large quantity of relatively small prey such as rodents until complete dietary studies are known. However, almost all of the prey thus far reported for this species is very large and impressive, much of it being presumably as heavy or heavier than the eagle-owls themselves. Due to being most widely reported as being chased and eaten by spot-bellied eagle-owls has led some authors to list their primary prey as pheasants. Among these, junglefowl ("Gallus" sp.) and kalij pheasants ("Lophura leucomelanos"), both weighing from , are commonly eaten, as well as Indian peafowl ("Pavo cristatus"), which can weigh anything from . The spot-bellied eagle-owl pounces on gamebirds while they're asleep on their perches in trees or bamboo clumps, often killing them in seconds with their powerful talons. Cases, where they've followed peafowl to their roosts and then pulled them out at sundown, have been reported. It also consumes an array of mammals, from small rodents to large prey such as apparent adults of golden jackals ("Canis aureus"), hares ("Lepus" ssp.), large Indian civets ("Viverra zibetha"), Indian spotted chevrotains ("Moschiola indica"), and even young muntjacs ("Muntiacus" sp.). These larger mammals are likely as much as or even more. While most reported prey appear to be largely terrestrial, they are known to capture arboreal prey including Indian giant squirrel ("Ratufa indica") and juvenile purple-faced langur ("Trachypithecus vetulus"). Additionally, they are considered a potential threat to toque monkeys ("Macaca sinica"), and one apparently caught an Indian flying fox ("Pteropus giganteus") from its tree roost. Due to the capture of diurnal prey such as giant squirrel, partial daytime foraging habits have been inferred for the spot-bellied eagle owl. They will also opportunistically prey upon snakes, lizards (including large monitor lizards) and fish. Like several of the eagle-owls and fish owls but unlike most owls, the spot-bellied eagle-owl has been recorded as feeding on carrion. Thus far, they've been seen feeding on the carcases of goats ("Capra aegagrus hircus") and tigers ("Panthera tigris"). European rabbit
The European rabbit is the only rabbit species that has been domesticated and all 305 global rabbit breeds—from Netherland Dwarf to Flemish Giant—are descendants of the European rabbit. Rabbits are an example of an animal that can be treated as a food, a pet, or a pest by different members of the same culture. In some urban areas, infestations of feral European rabbits (descended from pets) have become a problem. Helsinki, for example, host to one of the northernmost populations of the species, had an estimated 2,500 European rabbits at the end of 2006, doubling to 5,000 by autumn 2007. In Iceland, populations of "O. cuniculus" are found in urban Reykjavik as well as in the Vestmannaeyjar archipelago. In Finland, the introduced European rabbit vies with the native lagomorphs: the European hare and the mountain hare.