1. Anti-predator behavior
Chapter 5

2. Mobbing behavior Seen in birds like ground nesting black headed gulls
Scare off predators, protect young chicks
Flapping, kicking, droppings, screaming
Is it adaptive?
Does it occur because natural selection has acted on genes that allow/promote this behavior
Is it hereditary and does it lead to increased reproductive success?

4. Adaptations
Hereditary traits that give rise to a fitness benefit (genetic success)
Spread through the population in the past and is maintained by natural selection
Is currently spreading relative to alternative traits because of natural selection

5. Constraints on adaptation
Failure of mutations to occur
Can only select upon what is available
Particularly a problem for man-made environmental changes
Pleiotropy
Any gene may have >1 role in development and/or behavior
Allow maintenance of slightly negative trait (misdirected parental care)
Disallow positive trait if it leads to negative in another realm
Coevolution
The predator is undergoing selection too

6. Cost-Benefit analysis of mobbing
Cost: time and energy, loss of life, attract more predators
Benefits: prevent attacks on offspring
Predict:
mobbing should be especially effective against predators that don’t attack adults (crows)
Mobbing should result in fewer attacks

8. Comparative testing of adaptations
If a behavior is an adaptation, it should be selected for in species with similar circumstances

9. Mobbing behavior in mammals
These squirrels can adjust their mobbing behavior based on the threat assessment of the rattler—size and body temp of the snake signals its venomous danger levels to the squirrels and they are less likely to mob larger, warmer snakes which can move faster and inject more venom if they get a chance to bite their prey.
Siberian Jays will mob a model hawk more often during the day than a model owl, based on their knowledge of day vs night predators, risk assessment!

10. Dilution effect
Another group strategy for survival.

11. Swarming
The flip side of the dilution strategy. An organized defensive attack.

12. DQ Explain the behavior of these sleeping bees
Sleeping bees clustered together. Come up with 3 hypotheses about the anti-predator value of the sleeping clusters. What predictions does each hypothesis lead to?

13. Eggshell dispersal
Costs? Benefits?

14. Camouflage
Adaptive for solitary animals, but only against the right background

15. The black moth has almost completely taken over the population in the peppered moth (urbanization theory). Indeed, the most conspicuous moth to us is eaten most often by birds.

16. Is perch selection an adaptation?
Natural perch of the peppered moth is in shaded limb joints—if this perch is an adaptation, moths in limb joints ought to be more protected. Also, the typical (light) moth survives better in unpolluted woods, whereas the melanized (dark) moth survives better in the polluted woods.
Frequency dependent selection: the light form is coming back as pollution controls reduce the amount of soot in the air

17. How effective is cryptic perching?
Blue jays recognize only 80-90% of moths perched on their preferred substrate (birch) in their preferred, head up orientation. 100% on a darker substrate are detected.

18. Why does it work?
Conspicuous edges are used by inedible or poisonous prey so that predators can see and avoid eating them.

19. Receptive fields

20. Odor cue detection
Squirrels roll in shed snake skins to hide their odor
Snakes spend less time investigating squirrel+ snake odors vs. squirrel odor alone
Caterpillar larvae expel their waste far away from their leaf shelter to avoid detection by means of scent
Evolved to combat visual deception by prey

21. Predator is the paper wasp, who will find and kill a larva with its waste pellets over one without about 85% of the time.

22. Conspicuous behavior: a puzzle
Monarch butterfly: consumes toxic milkweed. Any bird that eats it will become sick and learn to avoid it.
Blister beetles (B) and this moth in C also harbor poisonous toxins.
Is learning inherited/selected on in predators? Or is this an example of indirect selection?

23. Starlings adjust feeding behavior based on toxicity perception
Grey-water injected worms, White-quinine injected worms
Toxicity determined by visual cues
Skelhorn and Rowe, 2010

24. More anti-predator strategies
Look like your enemy. Particularly, a threatening version of your enemy that will elicit its own innate escape response.
Experimentally, exchanging wings for clear ones reduces the benefit of jumping around, and placing tephritid wings on houseflies (who don’t jump) does not protect them. Need both the marked wings and the jumping behavior to deceive the real spider.

25. Conspicuous mammalian behavior

26. Solitary gazelles do stot, rule out 1 and 3
They also orient the rump at the predator, ruling out 2

27. Unprofitability hypothesis is supported
Two points: Is it an honest signal of escape probability? Hasn’t been tested, but probably, otherwise cheetahs would ignore it
Is it true for all members of the order Artiodactyla? No, all bovidae (gazelles are members) that have stalking predators stot, but deer (family cervidae) do not.

28. Optimality and Game Theories of anti-predatory behavior
Take into account benefit-cost, not just benefit
Both attempt to show that the behavior is better than the alternatives
Difficult to measure in nature

29. Comparing alternatives using optimality theory

30. Optimality theory applied to quail
Groups of 11 are superior in every way—survival, least movement, fastest response to predator silhouette, and maximal vigilance (watching for predators with head up)

31. Game theory of anti-predator behavior
“Winning” depends upon what strategy others are using
In a sparse population, a social mutant arises and clusters with another animal, using it as defense against predators—hide behind strategy
Social animal is successful, trait spreads
Might make herd more conspicuous
Individuals jockey for best positions

32. A selfish herd of penguins
Winners won’t be first or last into the water in case a seal is lying in wait.