willow willow bird subfamily family known willow ireland britain previously believed separate species red species breeding birch forests northern europe scandinavia siberia alaska northern canada particular province newfoundland state bird alaska summer birds largely brown plumage winter white black feathers tails british populations adopt winter plumage species remained little changed bird pleistocene nesting takes place spring eggs laid ground chicks soon leave nest young parents play caring chicks eat insects young plant growth adults completely eating leaves flowers seeds summer largely twigs willow dwarf shrubs trees winter description willow medium large ground dwelling bird numerous species males females size adult length varying centimetres wingspan ranging centimetres weight grams deep fairly long neck broad bill short legs moderately short rounded tail summer male plumage brown reddish neck breast black tail white wings eyes red prominent breeding season female similar appearance lacks brown feathers scattered white feathers belly winter plumage sexes completely white black feathers tail immature birds resemble adults willow distinguished closely related rock larger size thicker bill fact generally found tree line rock prefers elevated barren habitat summer plumage winter male willow lacks rock black stripe eyes bill white tailed north_america smaller white tail finely barred plumage lives permanently tree line distinctive british isles subspecies red considered separate true british species classified sub species bird reddish brown white feet voice low pitched includes repeated sounds displaying male makes noises taxonomy willow scientific derived hare foot reference bird feet allow negotiate frozen ground subspecies nineteen subspecies recognised believed valid differ little appearance red distinct taxonomy confused partly complicated changes plumage times year differing colour pattern summer plumage britain trondheim norway scandinavia finland north european russia baltic countries new siberia siberia southeast russia mountains west east siberia islands alaska british_columbia alaska arctic islands north canada riley north quebec newfoundland willow black occasionally western spruce rock pleistocene willow widely occurred continental europe authors recognize named pleistocene willow older correct marginally different birds said gradually changed earlier present day species pleistocene willow recorded diverse sites end years ago species identical living birds retreated northwards habitat distribution habitat willow distribution native canada united_states china czech_republic finland norway sweden estonia lithuania germany united_kingdom ireland spain primarily occupies habitats sparse pine birch forests willow trees heather mountain slopes winter females sub adults lower altitudes seek shelter valleys densely areas adult males usually remain region red common heather clad north west great_britain areas ireland diet willow varied seasonal diet bird life plant materials juveniles feed insects inability digest plant material caused summer diet highly varied consist flowers leaves twigs seeds alaska main item adults times year alaska willow leaves eaten summer twigs supplying birds main needs winter early spring early century increase expansion arctic alaska thought greatly affecting willow winter diet way help shape landscape area heavy birds access shorter shrubs snow eat taller species study found alaska willow reach stunt create feedback cycle extending entire ecosystem winters average snowfall drastic effect feeding spread range lower plant species believed parts arctic affecting populations altering shape size shrubs able feed behaviour male willow territorial birds males arrive breeding areas set territories april aggressively defending male females arrive weeks later male performs courtship displays aerial manoeuvres tail chosen mate nesting site female lays clutch eggs shallow depression ground nest site usually hidden location edge clearing small minority male willow guarding nest mate particularly early period eggs nearly ready hatch time greatest danger adult willow newly hatched young feed insects species female takes care young male willow helps feeding brood protecting completely female dies particular male defends young predators mate dive bomb lure attackers away pretending broken wing chicks face dangers range attacks birds prey getting separated rest brood bad weather fewer chicks survive months minority reach maturity despite favourable seasons juveniles survive population willow prone wide fluctuations size september families begin form flocks females young migrate lower altitudes miles breeding grounds wooded valleys hilly country males small groups usually travel far females state bird willow state bird alaska status widespread uncommon remote habitat willow classified species concern iucn suspected numbers declining slightly wide range total population estimated million individuals
Willow ptarmigan