anti predator adaptation anti predator adaptations mechanisms developed evolution assist prey organisms constant struggle predators animal kingdom adaptations evolved stage struggle line defence consists avoiding detection mechanisms camouflage living underground alternatively prey animals ward attack advertising presence strong defences mimicking animals possess defences startling attacker signalling predator pursuit worthwhile distraction defensive structures spines living group members groups reduced risk predation despite increased group improved predator confusion likelihood predator attack individual prey species capable fighting predators chemicals communal defence materials finally species able escape caught sacrificing certain body parts crabs shed shed tails distracting predators long permit prey escape avoiding detection staying sight animals avoid prey living sight predators caves underground nocturnal animal behavior characterized activity night sleeping day form animals avoid predation enhance prey hunting predation risk long recognized critical shaping decisions example predation risk prime importance determining time evening emergence bats early access brighter times permits easier foraging leads higher predation risk bat hawks bat results evening emergence time compromise conflicting demands nocturnal adaptation seen rats exhibit avoidance forage relatively open habitats reduce activity outside nest response moon shift activity areas relatively dense cover compensate extra controlled experiments artificial moon like illumination similar responses foraging behavior suggesting behavior evolved reduce predation risk camouflage camouflage uses combination materials coloration illumination organism hard detect sight common terrestrial marine animals camouflage achieved different ways resemblance surroundings coloration shadow elimination self decoration cryptic behavior skin patterns color animals flat tail north_america evolved eliminate shadow blend ground bodies flattened sides thin edge body form white scales fringed sides allows effectively hide shadows additionally hide remaining shadows pressing bodies ground attack species use strategies deter predators startling predator animals including butterflies cephalopods use patterns threatening startling behaviour suddenly displaying conspicuous scare momentarily distract predator giving prey animal opportunity escape pursuit signals pursuit signals signals prey convince predators pursue example jumping high stiff legs arched thought signal predators high level fitness predator result predators choose pursue different prey likely warning calls given birds jay similarly honest signals predator prey predator informed detected save time energy giving chase prey protected attack playing dead pursuit signal playing dead form bluff animal dead body death avoid attacked predators seeking live prey predator order lure prey approaching example seen white tailed deer experience drop heart rate response approaching predators response referred alarm causes heart rate drop beats minute beat heart drop heart rate minutes causing experience depressed breathing rate decrease movement called response causes enter low body position position dead corpse discovery predator loses interest dead prey additionally symptoms alarm including cause predator lose interest distraction marine sea squid chance escape distracting attackers mixture chemicals mimic food confuse predators response predator animals groups release ink creating cloud affecting predator feeding senses causing attack cloud distraction displays attract attention predators away object typically nest young protected distraction displays performed species birds broken wing ground species fish occurs organism mimic signal properties organism model confuse organism results mimic gaining protection food mating advantages classical types defensive involve coloration warning signals avoid attacked predator harmless prey species appearance species predators reducing mimic risk attack form seen insects idea predators tried eat species learn associate colors markings unpleasant taste results predator learning avoid species displaying similar colors markings including species octopus mimic selection animals changing skin color skin pattern body motion attacks octopus octopus banded sea snake model chosen varies octopus predator habitat use selecting organism predators model forms share warning signals monarch butterflies birds avoid eating species wing patterns honestly signal unpleasant taste defensive structures spine sharp needle like structure inflict pain predators example seen nature fish sharp like spine tail fins able inflict deep wounds area spines brightly colored advertise defensive capability predators avoid defensive spines barbed poisonous spines long stiff break tip barbed stick predator contrast short spines modified hairs readily bend barbed body easily lost attacker species numerous spines dorsal surfaces species possess spines suffer predation larvae lack predator paper wasp chooses larvae spines given choice safety numbers group living decrease risk predation individual variety ways described effect effect seen animals living group risk attack individual group proposed group living evolved provides benefits individual group conspicuous larger common example fish experiments provide direct evidence decrease individual attack rate seen group living example horses horse fly attacks horses blood carrying diseases flies numerous horses gather large groups individuals attacked frequently water insects live surface fresh water attacked beneath predatory fish experiments varying group size water showed attack rate individual water decreases group size increases selfish herd selfish herd theory proposed explain animals seek central positions group refers idea reducing individual domain danger domain danger area group individual likely attacked predator center group lowest domain danger animals constantly gain position study testing hamilton selfish herd effect studied brown fur seal predation great white sharks seals researchers varied distance produce different domains danger seals greater domain danger increased risk shark attack predator radical strategy avoiding predators kill large majority emerging young population emerge rarely irregular intervals strategy seen dramatic form periodical emerge intervals years predators life cycle years unable reproduce rapidly response emergence predator likely evolutionary explanation unusual life cycle predators feast emerging unable consume fraction brief prey alarm calls animals live groups alarm calls warning attack example different calls depending nature attack eagle leopard cat loud bark snake hearing calls respond defensively differently case eagle look run cover leopard run trees snake stand legs look snakes seeing snake mob similar calls found species monkey birds different calls different responses improved improved effect groups able detect predators sooner solitary individuals predators success depends surprise prey alerted early attack improved chance escape example wood flocks preyed successful attacking larger flocks wood attacking smaller flocks larger flock size likely bird notice hawk sooner fly away flies alarm rest follow wild national park kenya feed groups birds subject predation lions group size increases frequency individual raises head look predators decreases able run speeds exceed lions great distances lions try attack head grouping present lions greater difficulty determining long heads stay individual decreases overall group increases predator confusion individuals living large groups safer attack predator confused large group size group moves predator greater difficulty targeting individual prey animal suggested zoologist colleagues example stationary single stands large size reduce risk attack travel striped patterns herd confuse predator making harder predator focus individual furthermore moving rapidly stripes create confusing motion effect eye predator fighting defensive structures spines ward attack mentioned need fight predator methods fighting include chemical defences defensive chemical defences animals use poisonous chemicals self defence concentrated surface structures spines giving attacker taste chemicals actually bites prey animal bitter ditch defence animal flesh toxic fish butterflies insects acquire food plants accumulate toxic beetle specialized tip abdomen allows direct toxic spray predators spray generated sprayed temperature armoured similarly release blood joints threatened species including threatened venom threatened blind predator strikes eye species texas able shoot blood eyes rapidly increasing blood pressure eye threatened individual lose blood single persistent predators like wolves defence drop attempt shake blood mouths suggesting fluid foul taste choose given choice suggesting learned prey body enormous amounts provoked stressed gelatinous dramatic effects flow water rapidly gills fish attempt capture predators typically release seconds pictured common predators include fish suggesting predatory fish avoid prey communal defence communal defence prey groups actively defend attacking predator allowing passive victims predation predator prey animals usually protect young social colonies example red exhibit threatened common predator male red group place predators group females juveniles males jump actively bite birds nest colonies colonies mob approaching predators shown reduce predation levels defensive birds insects use defensive ward predators northern bright orange substance called stomach oil threatened stomach oil aquatic causes predator feathers mat leading loss flying ability loss water especially dangerous aquatic birds water feathers protect diving food european roller chicks bright orange foul liquid sense danger prospective predators alert parents danger respond delaying return numerous insects utilize defensive eastern tent digestive fluid repel attacking ants similarly larvae disturbed ants properties help deter predator attacks unusual type predator observed malaysian exploding social rely protect entire colony self destructive acts benefit individuals colony worker leg contents compounds predator prevent predation serve signal enemy ants stop predation rest colony escaping flight normal reaction prey animal attacking predator flee available means flying falling swimming running jumping according animal capabilities escape paths erratic making difficult predator predict way prey example birds black headed evade fast flight tropical rain forests southeast_asia particular escape predators falling insects turn sharply fall perform powered dive response bats fish follows path doubling chased fish eating duck animals capable self ditch attempt predator grasp distract predator allow escape lost body later certain sea crabs sacrifice successive shed tails attacked tail goes distracting predator giving time escape smaller tail slowly
Anti-predator adaptation