Defense Against Predators – Flashcards

Pepper Moth, change light to dark -switch in rareness -not fully successful so still have both patterns (hide in best places) -match background for cryptic coloration

-can't pick out an individual zebra, want to focus on one animal -predator contrast visual system gets confused -dark and light don't define animal -bias in nervous system, look at edges, enhanced when animals are moving

-mimic vegetation, octopus can match color pattern (chromatophores) -best are octopus and cuttlefish, not super energy draining -cell with pigments, neural/endocrine symbol expends clearly, goes from cleat to color, goes and activates different part of area -change texture via muscles, stays still and then inks and runs away, the makes itself as big as possible (defense mechanism) -don't move and act like vegetation

-lots of things mimic jumping spider predator -fly, when predator occurs it releases its wings and looks like spider -startles prey so gets away

-mostly herbivore mammals, go out of way to get noted but not fleeing -pretty effective, show predator they see you, lose element of surprise (sit and wait, others hide) predators just do something else or the prey gets away -usually in herd and all start jumping -honest signal to predator saying I'm in shape and healthy, best stutters are best in shape, harder to chase (bad condition, run)

-live in ground, predators are Pacific Rattlesnakes, gopher snake -adults can be bitten but children die so mob snake to protect burrow, know it is discovered (kick sand) -snake has infrared eye (heat, hot=red sticks out), highish resolution, project in visual section of brain

-show predator you see them, then start kicking sand -gopher snakes, not infrared, tail for visual cue, cold tail -rattlesnakes the squirrel pumps warm blood to tail to enhance signal

-rich food places (many resources) are often risky (watering hole) -safe and risky locations

-offered different sized food items at varying distances from the safety of trees -recorded proportion of items carried to safe cover -proportion of items carried increased with food size and decreased with distance to cover (small food you don't carry back to tree, bigger=carry more, greater handling time for bigger food so go back to safe tree) -food carrying represents a behavioral trade-off between predation risk and feeding efficiency

-social animal, hang out in groups, optimal group size, very flexible -daily survival rate, best survival at middle covey (group) size -daily movement (find food/harassment/in danger) -get most fit with middle covey size (no in group competition, more group vigilance)

Terns and wasps -group attacks are pretty effective -hornets flood out to surface of their hive (combined noxious effects)

-common pest, kill young trees, noxious to eat, disturb plants that are on they go nuts, start moving in weird ways together -get eaten but teach now sick predator (indirect fitness)

-sleeping male bees -males cannot sting -if disturbed they all go fly crazy, could be females...

-protect their eggs from mammals on ground nests by mobbing -predators are only successful if outside colony, also need cryptic eggs

-have stuffed weasel on track, see how it is mobbed -small colony: takes a while to see predator and attack it -more alarm calls with bigger colony -problem with graphs: outliers have too large of effect on the slope of the line, you have to work on what you have

-swap predators out, if you emerge in a large cohort/group you have a larger chance of survival, only some predators -predators become satiated so less change of eating you -individuals on edge of group are easiest to pick out -17 year cicada, no specialized predator, get full quick

-includes the dilution effect -fish shoals get really tight, ones on the outside are most vulnerable -try to push into each other, use others as shields (fighting for inside) -assume no kin selection, bunch of unrelated individuals

periphery individuals are more likely to be targeted, outsiders get picked off

-killer whales and leopard seals hunt penguins in water -one goes into water and all others immediately follow -disperse widely under water, then all get out of water en masse