BIO 200 Lecture Notes - Lecture 28: Snowshoe Hare, Nudibranch, Aposematism
18 Dec 2018
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Pred/prey cycling: show how pred and prey popns control & mirror each other a. Lynx and snowshoe hare- ~10 yr cycles; dramatic popn fluctuations. Cycling: limit strong pred pressure over time (low prey=low pred) Few predators: other factors like disease kill them off. Generalist predators: multiple food sources so dilute effects. Prey evolve to avoid predation: crypsis: disguise. Cryptic coloration- camouflage [you can"t see me] Object mimicry- being mistaken for s/t inedible [i ain"t what you want: chem defense: spraying noxious liquids, toxicity: either make poisons themselves or take shortcut. Shortcut: nudibranch- eats toxic jellyfish, transferring poison to own body. Aposematic coloring- brightly colored nudibranchs warn pred away to reap benefits. Pred needs prev neg experience before knowing to avoid in future. Batesian mimicry- non-poisonous mimic poisonous model species. Faster learning process: once pred tries one, it"ll avoid all. Monarch & viceroy butterflies: armor: exactly what you think. Overwhelming brightness/beauty is usually a warning sign.
