Davies, Krebs, West, An introduction to behavioral ecology
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Chapter 1
1. Starlings choose foraging sites to be in a group or not, to eat certain foods, and when to return to chicks. They also choose nest site, number of chicks to have, a mate, and how hard to work at caring for the chicks. Categorize these choices according to a sorting you devise, into two categories, not necessarily of equal size.
2. What are Tinbergen’s four questions? How do they differ? How are they similar? Give an example of each of the four that you would ask for a specific organism, perhaps the starlings.
3. What are all the ways relatedness impacts social interactions in lions? How does it vary with sex and age? Make a diagram.
4. What is the difference between proximate and ultimate causation? What is causation?
5. Why do female lions come into estrus synchronously? Think of at least two hypotheses. How might you test them?
6. Why do male lions kill cubs? Why do females mate with their cubs’ assassins? How would you test your hypothesis?
7. What are the key requirements for natural selection according to Darwin and what are they according to the genic view? What are the differences? What is the advantage of the gene-based view?
8. Why do we focus on differences when we study adaptation?
9. In Drosophila there are rovers and sitters. How do they differ? What role does the environment play and what role do genes play? What maintains the polymorphism?
10. How might understanding the pathways involved in foraging expression help understand how the gene works in flies and honeybees?
11. Why might coat color polymorphism be common?
12. Why might blackcaps vary in migratory behavior? Think of hypotheses for all four of Tinbergen’s approaches.
13. What is Wynne-Edwards hypothesis of group selection? What evidence did he think supported it? What is the problem with the idea?
14. What is Lack’s hypothesis? What did its tests at Wytham Woods near Oxford show? Why is this important?
15. What are all the factors that need to be considered in clutch size experiments? Graph it.
16. What are the tradeoffs between survival and reproduction? Graph it. What is an individual surviving for?
17. Why do some magpies produce large clutches?
18. What is a genotype? What is a phenotype? Which changes most rapidly with climate change? Give an example.
19. What is phenotypic plasticity? Why is it important? Give an example.
20. What is the story about English and Dutch great tits and breeding time? Which population might go extinct first?
Chapter 2
1. What do researchers do before they begin to generate and test hypotheses? Why might observation and hypothesis generation go together?
2. What are the three ways DKW say you can use to test hypotheses? List strengths and weaknesses of each.
3. Give the reasoning steps in the logical order that Darwin used to argue that mammal skull sutures did not originate to facilitate birth.
4. Table 2.1 compares the black-headed gull with the kittiwake for a number of traits. Use this information to generate a hypothesis. It is ok to use the one in the book. Which variables are responses and which are independent? Give the logic for a prediction for each variable. Which ones are least related to your main hypothesis? Why?
5. What is the problem with comparing black-hooded gulls and kittiwakes?
6. What is Crook’s argument about weaver birds, diet, coloration, and habitat? What are its strengths and weaknesses? How would you go about disproving it?
7. Why did Crook only consider weaver birds? Was this a good idea?
8. Compare and contrast Jarman’s study of African ungulates with Crook’s of weaver finches.
9. What are the main problems with these early comparative studies?
10. Why is it best to think of as many possible hypotheses as you can before beginning a study?
11. What if you think of a new hypothesis in the middle of a study? What should you do? What should you be careful of?
12. How might we distinguish cause and effect in any of the early comparative studies? Why is it important to do so?
13. Why were the advances in the comparative method by Clutton-Brock and Harvey so important? They are: 1 Treat variables as continuous not categorical; 2 They considered alternative hypotheses and used multivariate statistics on ecological variables; 3 They used genera as data points not species.
14. What are confounding variables and how do you reduce problems they cause?
15. What are some hypotheses for sexual dimorphism? How would you test one of them?
16. What is a phylogeny, how is it constructed, and why are phylogenies important?
17. How can you tie a phylogeny to actual time? Compare molecular clocks and fossils.
18. What are independent contrasts and why is this so important? What improvements did they make?
19. What more can we learn if we know the actual order that traits arose? Use primate sexual swellings as an example.
20. One of the biggest problems with experiments in animal behavior is that animals must be able to respond to the differences tested in the experiment. They will not evolve a new response just because you introduce a new condition. What would you do to take this into account in designing an experiment?
21. Critique the egg removal example in oyster-catchers and black-headed gulls using what you have learned in this chapter
Chapter 3
1. How many larvae should a starling carry back to the nest? What variables are important in determining this answer? Graph it.
2. What did Kacelnik’s experiment do that could not be done with natural feeding?
3. Why do bees return to the nest before they are full?
4. What is the marginal value theorem? Why is it useful? Give an example with a graph.
5. How long should male dungflies spend copulating? How do they know? Would your prediction change if the male knew he was the first, second, or subsequent mate?
6. What besides mating might a male dungfly do to increase his paternity?
7. What differences in male behavior would you expect depending on if he was in a dense patch with lots of males or in a sparse patch with few? How does this vary depending on if males or females or both are dense or scarce?
8. Compare and contrast the use of the marginal value theorem to explain starling foraging and dungfly mating. How does frequency dependence impact each?
9. What did Schmid Hempel show with weights on the backs of bees? What was the currency of measurement. Why is this a good currency and why is it a bad one?
10. Why does currency matter in cost-benefit analyses?
11. Why don’t shore crabs prefer to eat large mussels? What do you think would change if the crabs were offered two species of mussels that different differed in the relationship between size and hardness? What are all the variables needing consideration? Design an experiment to test your hypothesis.
12. Use the model from Charnov in Box 3.2 to predict how a predator should choose prey. Put in some values, draw a graph and say what you would do to test the model.
13. Describe and discuss the test of the prey handling model in great tits and worms of two different sizes. What might you do to improve the experiment?
14. What did Lima do to study learning while foraging in downy woodpeckers? What kinds of organisms are amenable to experiments like this one?
15. Foraging currencies include rate of food intake, efficiency, and risk of starvation. Can you think of others? Compare and contrast these. Which is likely to be important for any given bird species?
16. How much less food might an organism accept for a more certain delivery? What does this depend on? Why might time of day matter? How about predation risk?
17. Why did temperature change yellow-eyed junco foraging decisions? Why might bumblebees be less risk prone?
18. Why would a songbird in winter carry less fat than it could? What do you predict about changes during the day?
19. Why did great tits lose weight after sparrowhawks returned to Wytham Woods?
20. What is the argument that birds that scatter hoard seeds have to remember where their own seeds are? How was this tested in willow tits?
21. How did Sherry and colleagues show that marsh tits actually remember where seeds are stored?
22. What do London taxi drivers have in common with Clark’s nutcrackers? Why do you think hippocampus volume and the associated impact on memory is a plastic and not a fixed trait evolutionarily speaking? How would you test your hypothesis?
23. Where would you expect larger hippocampus, Alaska or California? Why? Think of some other contrasts to make predictions.
24. What is the difference between episodic memory and procedural memory?
25. What does allowing birds to hide both worms and seeds tell us that the seed only experiments did not?
26. Why does a bird care if it has been observed hiding food? What do scrub jays do when observed? What do you expect of other birds?
27. Why might dominant birds be less likely to move their caches than subordinate birds? Under what circumstances do you expect birds to share their caches?
28. Why would a scrub jay store dog food in the pine nut room and vice versa? What are the strengths and weaknesses of the food choice experiments like this done under artificial circumstances?
29. What kinds of intelligence and foresight do these learning experiments demonstrate? Why might animals be more like people, or people more like animals? What do you think a human would do with the dog food/pine nuts experiment (perhaps changed food items)?
30. What most intrigues you about bird intelligence? Design an experiment that would test a hypothesis in this area using insights from the experiments in this chapter.
31. Why don’t the squirrels of Lima’s experiment learn that you won’t hurt them and stay at the picnic table? Why should this behavior be any less plastic than some of the caching behaviors discussed earlier in the chapter?
32. Design a semester long experiment on squirrels and picnic tables. Assume you can tell the squirrels apart, perhaps with spray paint.
33. Why would a stickleback ever choose to forage where food is less dense?
34. Compare the kinds of foraging behavior experiments researchers do with birds vs. fish. What is easier with fish? What is easier with birds? What is the same and what is different.
35. Give three examples of social learning. If social learning for foraging is so effective, why is it not more universal? What does it require? What are its costs and benefits?
36. What is the difference between social learning and teaching? Give the three necessary attributes of teaching. Why does it not require a large brain? Give examples.
37. Why shouldn’t meerkats just skip eating dangerous scorpions? What risks do adults incur in teaching the pups how to eat scorpions?
38. How can we tell when animals or humans operate from simple behavioral rules rather than complex cognitive mechanisms?
39. What is an optimality model? What are its strengths and weaknesses? Give examples.
Chapter 4
DKW 4 Study Questions Predator Prey
1. How does the red queen hypothesis apply to predator interactions with prey? What exactly is the red queen hypothesis?
2. Give three predator actions and adaptations and the evolved responses of the prey. Can you think of other things than are in table 4.1?
3. Discuss the evidence the Daphnia (water flea) example gives for predator prey cycles. Design an experimental evolution study that would get at the same thing. What organisms would you use? You have only 2 years to do the study.
4. Describe the blue jay experiment on crypsis. Why do you think it was all right for the investigators to use blue jays that were simply shown photos of the prey?
5. Underwing moths have cryptic forewings and scary underwings. Why are the forewings more variable than the underwings? How would you test a hypothesis on this?
6. What is a search image? What experiment did Marian Dawkins do to show that this mattered in chickens?
7. Summarize the studies on bird predation and moths. What is looked at? What do the experiments have to be careful about? What are the big conclusions?
8. When should the great tits ignore straws with mealworms in them? How does this experiment compare to the ones Stephens and Kamil did with blue jays?
9. What is the difference between masquerade and crypsis? Which do you think is likely to be more effective? Which is more likely to lose its power over time with the same individuals? Why?
10. Why are the dendrobatid frogs that eat ants brightly colored? How would you test your hypothesis? (Don’t even think about feeding them something different and letting them “evolve” change.)
11. Come up with a theory on bird intelligence and diet, along with a test.
12. Why are gregarious locusts (grasshoppers) brightly colored, and solitary ones of the same species not?
13. How did distastefulness and bright coloration evolve? What is the problem? Why might family groups be important?
14. What are Müllerian and Batesian mimicry? Which do you expect to have tougher skin? Give examples of the two kinds of mimicry.
15. What are the tradeoffs between temperature and color, and between offspring production and toxin metabolism? At some level, we could say everything is about tradeoffs. Think of some other situations in this chapter that probably involved tradeoffs and give two examples and state why you think tradeoffs are involved.
16. What is the evidence for a tradeoff between crypsis and territoriality? How might it be moderated?
17. What happened to guppy coloration with increasing predation? Why do you think the variability existed in the population to make the selection experiment so successful?
18. Describe nest parasitism by the common cuckoo, Cuculus canorus, in Europe. Why does the mother eject only one egg when she parasitizes, even though the cuckoo chick will subsequently eject the remaining host eggs?
19. Why can’t cuckoo hosts tell that the cuckoo baby is not their own?
20. Why are some cuckoo hosts better at recognizing cuckoo eggs? What do the cuckoos do about it? Are these evolved or plastic responses? How would you test your hypotheses?
21. When we say “hosts evolve to reject cuckoo eggs,” what exactly are the steps involved? List them, beginning with hosts accept cuckoo eggs.
22. What does signaling theory tell us about cuckoo egg acceptance and rejection? Think about applying signaling theory, as described in box 4.2, to a non-cuckoo example in the chapter.
23. Compare and contrast how natural selection is likely to work on predator-prey situations that evolve crypsis, those that involve warning coloration, and cuckoos.
Chapter 5
1. Frequency dependence is a very important concept in evolutionary biology. What is it and why is it so important?
2. What is an Evolutionarily Stable Strategy (ESS)? What do you have to know to formulate one? Why are they not necessarily the best for all or even on average?
3. Deascribe Hawk Dove in detail and what an ESS is under Hawk Dove.
4. In what ways is hawk dove too simplistic? How would you modify it?
5. What is the ideal free distribution between rich and poor habitat? In what ways is it unrealistic? Give examples and graphs.
6. What is natural and what is not about Manfred Malinski’s experiments on cichlid feeding?
7. Why would a male dungfly ever leave a female when he is mating? Howe does this differ from the spider example? If you came a cross a mating pair what variables would you need to collect to understand when the female and male might desire to end the relationship? Keep in mind that most arthropod males deliver sperm gradually, not all at once.
8. How might territoriality at a resource that is attractive to females, like a dung pat, or a pond, change mating time and choice variables?
9. Why is the concept of economic defendability important? What variables and what relationships among them are important?
10. What is the story on pied wagtail territory sharing? How would you rule out the hypothesis that there is no active sharing, but just different costs and benefits to chasing off intruders?
11. What is the concept “best of a bad job?” Is it useful or not? When and why? To whom does it apply?
12. What determines when producers or scroungers or any two alternative strategies have an equilibrium, as opposed to one always being worse than the other? Do the differences in strategies depend on there being differences in the individuals? Explain.
13. Discuss ruddy turnstones and spice finches.
14. What is a strategy and what is a tactic? Why are both necessary terms? Give an example.
15. Why do some natterjack toads refrain from calling/ How does this differ from the horseshoe crab?
16. Natterjack toad males, if they survive, eventually grow to be large enough to be callers. By contrast, Onthophagus beetles either have horns or don’t, fixing their strategy for life. Does this matter for understanding the two strategies? Why the difference?
17. Describe the Onthophagus story in detail. What do the Hunt and Simmons experiments add? How did Emlen show the trait had a genetic basis? Why are beetle horns a more tractable system than calling frogs for study in alternative strategies?
18. Why should genetically determined alternative strategies have, on average, equal success? Does this mean most alternative strategies are environmentally, not genetically determined.
19. What is frequency dependent selection? How does it apply to alternative strategies? What else might it apply to?
20. Discuss polymorphism in ruffs, Philomachus pugnax. What might help keep three morphs stable? Is this likely to be the same in isopods, Paracerceris sculpta? Why do the female mimic males have such huge testes? How would you test your hypothesis?
21. What are the three strategies of side blotched lizards, Uta stansburiana and why do they vary in frequency? What is a rock/paper/scissors hierarchy and how does it differ from the previous stories like ruffs or beetles?
22. What is ESS thinking? Why is it important? How does it tie to the strategy/tactic difference? How does it tie to genes?
23. What is an animal personality? Give an example. How do they relate to strategies, tactics and ESS? Why is frequency dependence likely in animal personalities? How would you test your hypothesis?
24. Why, throughout this chapter have the behaviors of others been so important?
Chapter 6
1. What is the problem with the hypothesis that groups form to benefit the population or species? How would you test this idea?
2. How does the dilution effect work in water skaters (water striders)? What would a figure showing the dilution effect look like? Are the effects similar or different in horses and monarchs?
3. How does the predator swamping hypothesis differ from the dilution effect? How do the groups differ? How would you tell which is the best explanation? Give an example of each.
4. What is a selfish herd? How are they organized? Give an example.
5. Make a chart of the hypotheses farvoing grouping as a defense from predators and what they predict. Use graphs.
6. Discuss vigilance, predation, and group size. What is the cost to vigilance and how might you measure it?
7. What keeps vigilance honest?
8. What is an information center?
9. At what life stages do animals group and how does this influence the costs and benefits of grouping?
10. Why would it ever be advantageous to attract others to a food resource you discovered?
11. What did the plastic pellets tell us about raven foraging?
12. What do schooling tradeoffs in guppies show? What is special about the Magurran study? What other studies show tradeoffs in grouping?
13. What are the costs of grouping? What impact do these costs have on grouping?
14. What is an optimal group size? Work back through some of the examples and think about what factors contribute to optimal group size. How might you test your ideas?
15. How do the interests of the group and the individual play out in optimal group size? Does this lead to larger or smaller groups?
16. What is skew? How does it apply to grouping?
17. Why would a hungry animal ever refuse food?
18. How can groups make decisions apart from those of the individuals in them? How does this behavior evolve?
19. What kinds of evidence led Couzin and Franks to conclude that army ants have three rules: 1. That they follow pheromone concentration gradients; 2. That they go away from the colony without food, towards it with food, and 3. That outbound ants move out of the path of inbound ants? Do you agree with their conclusions? Why?
20. What are the strengths and weaknesses of using computer simulations to test hypotheses?
21. In fish schools what is the difference between a swarm, a torus, and a directional group? How does school organization change in the presence of a predator?
22. How can researchers show that fish do not count in determining the size of the group they join?
23. What is opinion polling and how does it work in animals? Give two examples.
Chapter 7
1. Why did Darwin feel he needed an additional theory, sexual selection? What are its two main components?
2. What is anisogamy? How might it have evolved? How do data from Volvocales support this hypothesis?
3. Why do protists, single-celled eukaryotes, lack anisogamy?
4. Why does Trivers view parental care as an analogous investment as a large egg? How does this affect how we think about sexual selection?
5. What’s more important for natural selection, the maximum reproductive rate as shown in Table 7.1, or some other metric? What other metric and why, if this is your answer.
6. Queller has two general reasons for why females should be more likely than males to take care of the young. What are they and how do the arguments go?
7. How does sexual selection explain sexual dimorphism? What conditions explain sexual dimorphism? Give examples.
8. Describe Malte Andersson’s experiment on widowbirds and indicate how it demonstrated female choice.
9. Why should there be a tradeoff between red color and tail length considering widowbirds and red bishops?
10. What are the likely differences in physical characteristics in males that offer females good resources vs. good genes? Give examples.
11. Compare and contrast longtailed widowbirds, sedge warblers, hanging flies, bullfrogs, and satin bowerbirds. Make a table.
12. How does Zahavi’s argument for handicaps work? Why might a handicap tell a female about the genetic quality of her mate. Give examples.
13. How did Marion Petrie use peacocks to test the good genes hypothesis? What exactly is the good genes hypothesis? What controls did she use?
14. What is the Hamilton-Zuk hypothesis? Why does it predict greater parasite loads on species with more colorful males? What is the relationship between male color and female choosiness within and between species?
15. Discuss the four key assumptions of the Hamilton Zuk hypothesis: 1) that parasites reduce host fitness; 2) that parasite resistance is genetic; 3) that elaborate ornaments signal parasite resistance; and 4) that females prefer males with the most elaborate signals.
16. Describe the Milinski and Bakker experiments and indicate what elements supported which paths of the Hamilton Zuk hypothesis. How does the MHC complex play into it?
17. Discuss female ornamentation and its relation to sexual ornamentation theory. When do you expect both sexes to be ornamented and when just females?
18. How might you show that ornamented females are not just co-selected nonadaptive correlates of male characteristics, but selected in their own right?
19. What are the similarities and differences between sperm competition and precopulatory sexual selection?
20. What are all the reasons a female might copulate with multiple males? How would you test your hypothesis?
21. Critically examine the hypothesis that extrapair copulation opportunities drive coloration in male birds.
22. Why do you think the social mating system in birds was not correlated with plumage dimorphism in birds?
23. Why should mating with multiple males lead to greater offspring survivorship? Why not just pick the best guy and mate with him?
24. In what sense are relations between mating males and females an arms race and in what sense are they not?
25. What variables come into play on forced copulations? What other kinds of sexual conflict are there?
26. If females are not faithful, why do males ever care for young? How would you test your hypothesis?
27. Why would female spines and male abdomen shape ever coevolve?
28. What do males do to increase their paternity when females mate multiply?
29. What are parasperm and how do they evolve? How do they differ from accessory gland proteins?
30. What is the significance of testes size?
31. Are postmating conflicts more important to the male or the female? What are the consequences of the differences?
32. Discuss duck genitalia and arms races.
33. Diagram William Rice’s experimental evolution experiment with Drosophila and mate conflict.
34. What is antagonistic coevolution?
Chapter 8
1. Compare ad contrast conflict between male and female parents, conflict among siblings, and conflict between parents and offspring, over parental care. Consider genetic relatedness, probability of relatedness, costs and benefits to each party and other variables that might be relevant.
2. Given that parental care is so rare in organisms, including most animals, why does it ever evolve? (What is an animal?) How would you test your hypothesis?
3. What can parents do to increase the survival of their young? List as many ways as you can think of. How does this represent tradeoffs in numbers of offspring?
4. Why, when, and where do males care? Why, when, and where do females care? (By care we mean care for young.
5. List parental care types in invertebrates, fish, amphibians, reptiles (excluding birds), birds, and mammals. What are the similarities and differences and why have they evolved?
6. How does whether fertilization is internal or external to the female impact parental care? Give three hypotheses and how you would test each.
7. What is parental investment according to Trivers? What behaivors is it made up of? What is lifetime parental investment?
8. What are parental investment tradeoffs within broods according to Lack? How does this influence parental investment between broods?
9. What are the different things that go into a parent maximizing lifetime reproductive success? Be complete.
10. What is more valuable, current or future brood? Why? Does your answer vary with age or increasing or decreasing population size?
11. Figure 8.2 shows the relationship between costs to parental investment that increase linearly, and benefits to the offspring that level off. Parents should choose to invest where costs and benefits are fartherst apart. Why are benefits convex and costs linear? Under what circumstances might these curves take different shapes?
12. What did Ghalambor and Martin predict about risk taking in response to predators in the temperate and tropical regions? Was their hypothesis supported? Can you make other similar predictions based on other circumstances that might affect adult vs. brood survivorship?
13. What hypotheses did Balshine and Earn test on St. Peter’s fish? What did they find? What other variables might they have considered and why?
14. Why would a parent ever eat their young? Why might this be particularly common in fish? How would you test your hypothesis?
15. Some females lay larger, better eggs when mated with more attractive males. Under what conditions or mating systems would you expect this to evolve?
16. Sexual conflict between males and females that have mated occurs over who should provide parental care and how much to provide. Each parent’s staregy depends on what the other does. This is not necessarily highly variable. Discuss what things you would want to know to predict the outcome of this conflict in a species.
17. If one parent does not give enough care, why does the other parent not compensate fully?
18. Why do you suppose that great tit parents feed more when there was a begging speaker? Why would the other parent also increase its effort, even not hearing the speaker?
19. Diagram and discuss the role of genetic relatedness in parent offspring conflict.
20. What is siblicide? What circumstances favor its evolution? What circumstances increase its occurrence in a given year?
21. Why do chicks beg loudly? What influences their begging? Why are parents so susceptible to it? What do coot studies show?
22. What is the evidence for parent offspring conflict? How do you distinguish it from normal developmental maturation? Give examples.
23. What are the costs and benefits of synchronous vs. nonsynchronous brooding in birds? Give an example.
24. Why should it matter which parent you inherit a gene from? Explain genomic imprinting in insulin like growth factor.
25. Why should begging levels differ among nests? How did Kilner show this? Discuss co-evolution of begging in canaries and burying beetles.
26. What is a maternal effect compared to a genetic trait? Give an example.
27. What is a brood parasite? Give examples. How much should they beg?
28. Compare and contrast cowbird and cuckoo behavior. Why the difference? How would you test your hypothesis?
29. Why should parents’ interests or their own young’s interests ever differ?
Chapter 9
1. What is meant by a mating system? Explain the different kinds. What kinds of sexual reproduction are apparently left out of table 9.1?
2. Why does resource distribution (food, nesting sites) influence breeding system? Describe with a figure and two examples.
3. What is the mating sex ratio? Why does it vary? Give examples.
4. What do the grey sided voles and the blue head wrasse studies show? What do they have in common and how do they differ? How might you expand either study?
5. Compare and contrast the four kinds of mammalian mating systems: 1) females solitary:range defensible by male; 2) females solitary: range not defensible by male; 3) females social, range defensible by male; 4) females social: range not defensible by male. How would you test the hypothesis that female range determines the mating system?
6. Draw a figure or figures of male and female interests and how they come together in mating systems.
7. What is a lek? Where do they occur? Why do you think they are rare? In what ways could they benefit males? In what ways could they benefit females?
8. Compare and contrast the five hypotheses for leks (hotspots, predation reduction, increase female attraction, males aggregating around good males, and female mate choice). The book implies that different hypotheses work best for different organisms. What data would you want to collect for a comprehensive hypothesis on lekking? What do you think the most general hypothesis is? How would you test it?
9. What is phylogenetic inertia? One example is that mammals have females predisposed to care for young with milk. Do birds have anything analogous? Compare and contrast breeding systems in birds and mammals with phylogenetic intertia in mind.
10. Why are so many birds monogamous? What is the difference between social monogamy and genetic monogamy? Why do they differ in so many bird species? How would you test your hypothesis?
11. Look at part B of Fig. 9.8. that shows red winged blackbird male territories, their paternity in the brood they raised, and their extra-pair paternity. What causes the patterns? Do males mate extra-pair their closest neighbors? Are some males preferred as mates by everyone? Do males with the greatest extra-pair success also have the greatest success with their own mate. Draw a table with territory size, within pair success, extra pair success, and distance (measured in territories) of extrapair success to help with your conclusions.
12. What is resource defense polygyny? When would a female choose to be the second female on a male’s territory when she could be the first female on a different male’s territory? Use a figure and an example in your answer.
13. What are the costs and benefits of polygyny? For females? For males? Give examples.
14. What do we learn from experiments vs. comparative method on the evolution of polygyny? Give examples from each technique.
15. In what way is the polygyny threshold model like the ideal free distribution? What are the strengths and weaknesses of models like this? Give an example.
16. Why might a female pied flycatcher ever become the second female? Do you think they know there is someone else? What would you do to be sure he didn’t have another mate? How would you test your hypothesis?
17. What is the sexy son hypothesis? What are its weaknesses?
18. How would you determine whether or not it is deception or lack of single males that is involved in polygynous mating in the pied flycatcher? What clever test did Alatalo do? Apply this also to another bird species you have read about.
19. Discuss the mating system of the dunnock, Prunella modularis. Why is it so complex compared to other birds? Why do females ever mate polygynously if polyandry is a more successful strategy?
20. What kind of limitation is the clutch size of 4 in shorebirds? Why does it lead to polyandry? Give examples.
21. How important is the ability of males to desert first in some systems in determining who cares for the babies? What other reasons might males care less than females? How would you test your hypothesis?
22. Can you put the three themes of mating systems (life history constraints, ecological factors, and social conflicts) into a broad framework that will predict each system? Consider also which ones are phylogenetic constraints and which are more plastic. Is Table 9.3 helpful in your thinking, or do you have another plan?
Chapter 10
1. What does dioecious mean? What organisms are dioecious? How do their decisions regarding sex compare to those of sequential hermaphrodites?
2. How is sex determined in turtles, wasps, mice, and blackbirds? What difference does sex determination make for sex allocation?
3. What is Fisher’s theory of equal investment in the sexes? What brings a biased sex ratio, say in a small population, back to equality? Is the process likely to differ between turtles and mice? How?
4. What exactly did Alexandra Basolo in 1994 do with the southern platyfish Xiphorus maculatus to support Fisher’s theory of equal sex ratios?
5. How does the equal sex ratio argument change if males are twice as costly to produce? Costly to whom?
6. What is local resource competition? Under what circumstances does it impact sex ratios? Why do males and females sometimes disperse different distances? Towards which sex is the sex ratio biased when it is biased because of local resource competition?
7. Why are sex ratios so biased in army ants? Is the sex investment ratio also biased?
8. What is local mate competition and how is it similar or different from local resource competition? Explain the reasoning behind two arguments for local mate competition, 1) that males devalue each other, and 2) that, under inbreeding, a female-biased sex ratio provides males with more sisters as mates.
9. What precondition for equal sex ratios is generally violated under local mate competition?
10. Why do female parasitoid wasps produce a less female biased sex ratio when laying eggs in a patch in which another female has already laid eggs?
11. What is the logic behind Pen and Weissing’s argument that in species with helpers at the nest, groups with helpers should produce the non-helping sex and groups without helpers should produce the helping sex?
12. Describe in detail the experiment of Komdeur using Seychelles warblers to study local resource competition and local resource enhancement. When and why do female Seychelles warblers produce 2 eggs? What other numbers do they lay? Why the variability?
13. Under what circumstances are sex ratios less adjusted to resources, according to Griffin? What is her evidence?
14. What is a meta analysis? What are its strengths and weaknesses? How can meta analyses find significance out of a whole set of studies that are insignificant on their own?
15. What is the Trivers-Willard hypothesis? What are the assumptions? Is the hypothesis supported? Discuss red deer. How did Sheldon modify the hypothesis to apply it to blue tits? What did he find in blue tits?
16. Under what circumstances should males emerge first in species with environmental sex determination?
17. Discuss sex change. Where does it occur? What sex is likely to emerge first? Why? Give 3 examples.
18. What is sex ratio distortion? Discuss driver X and Wolbachia and give examples of their action in 2 animals.
Chapter 11
1. Explain the definition of altruism, that a behavior is altruistic if it is costly to the personal reproduction of the actor that performs it and beneficial to another individual. What exactly does it mean?
2. How does Hamilton’s classification of social behaviors into mutually beneficial, altruistic, selfish, and spiteful work in terms of gain to actor and recipient? Can you give an example of each kind of behavior?
3. Why would you count parental care as altruism? In what sense is it not?
4. What exactly is relatedness? Diagram relatedness between cousins, siblings and parents and offspring according to the method in the box on page 11.2.
5. What is inclusive fitness? Why is it tricky to define? How do you avoid double counting? Why is inclusive fitness so hard to measure, even if you are careful not to double count?
6. What is kin selection? What is its relationship to inclusive fitness?
7. Explain Hamilton’s Rule, rb-c>0 and give an example. How does this work at the level of the gene?
8. How many extra offspring would it take to favor a gene which causes you to help your mother raise your full siblings and not reproduce yourself?
9. What did Paul Sherman figure out about ground squirrels? How do males differ in whom they interact with compared to females? What is the result of this behavior? Discuss alarm calls and infanticide.
10. Describe the black-tailed prairie dog studied by John Hoogland. How do they differ from Beldings ground squirrels in social structure and altruism?
11. Why would a male turkey help another achieve matings? How does this study support Hamilton’s rule?
12. What is a greenbeard gene?
13. What is kin recognition? Why is it important? What is the armpit effect?
14. Why are social amoebae so cool? What is their social cycle? How did the researchers show they recognize kin?
15. What is the advantage to a simple kin recognition rule, like if they are in my nest, they are my relatives? What is the cost? Give an example.
16. How does kin selection explain siderophore production? What is a siderophore? Who produces them and why? Draw a picture.
17. What kinds of population structure favor siderophore production?
18. How do you measure relatedness in microbes?
19. Discuss cannibalism in tiger salamanders. What is so interesting about it?
20. What are all the hypotheses that Pfennig et al. tested for tiger salamander cannibalism? Why did they settle on kin selection?
21. What is spite and when might it evolve?
22. What color would the belly of the actor be in B11.5.1 where A is ¾ green, and B is ¼ green, and C is ½ green and the population is ½ green? Why is this figure useful in explaining relatedness?
23. What are bacteriocins? In what sense are they kin selected?
Chapter 12
1. What do they mean when they say cooperation is not just about kin selection? Does this disprove kin selection? Why or why not?
2. Compare and contrast the requirements for kin selection, by-product benefits, reciprocity, and enforcement. Give an example of each. What kinds of cooperation are not covered by any of these? What kinds overlap?
3. What is cooperation?
4. Why do they exclude a one-way benefit from cooperation? Give an example.
5. Think about the similarities and differences beteen service mutualisms like clearner fish and legume-rhizobia ones as compared to microbial secretory mutualisms. Compare and contrast.
6. What is a free rider? Give an example. What is a free rider in the human system of prisoner’s dilemma? Why does it make cooperation unstable? What is the solution?
7. What is direct fitness? What is indirect fitness? Give examples.
8. Figure 12.2 is a good breakdown of the kinds of cooperation. Return to it as you work through the chapter. The elements in the table are not all analogous. Some involve recognition. Others involve power. Others involve self-interest. Others involve ecology. Think about how you might classify these and other elements. Come up with a chart that is more clear to you on these variables. Give examples.
9. What did Ben Hatchwell show with long-tailed tits?
10. What is Hatchwell’s argument on why the tits show direct or indirect fitness, but not both? Do you agree? Why or why not?
11. A study of the superb fairy wren did not show any increase in chick mass from helpers. What instead were the benefits? What exactly did the mothers do differently and what were the consequences?
12. How does game theory apply to cooperative hunting? In what sense is it frequency dependent?
13. Why do unrelated ants cooperate? Why do they have fights to the death when the cooperative hunters in the ESS example keep cooperating?
14. Use group hunting as an ESS, cooperative nest founding in ants, OR group augmentation by meerkats to explain by product benefits. What are some other by product benefits? Is this cooperation? How does it compare to other kinds of cooperation?
15. Why be a meerkat baby sitter? What are the costs, benefits, and alternatives? How does it differ between the sexes?
16. Why in meerkats is it hard to separate direct and indirect fitness effects? Discuss this issue for two other animals that have some form of cooperative breeding.
17. What is reciprocity? What are the requirements for it to happen, cognitive and otherwise.
18. Give some examples of reciprocity in humans. Why don’t people cheat more often? When do they cheat?
19. Discuss blood sharing in vampire bats. Give a hypothesis and a test of it to best explain blood sharing. What data would disprove your hypothesis?
20. Explain mating in olive baboons. How has this behavior evolved?
21. What are the problems with animal examples that claim to support reciprocity?
22. Discuss all forms of infanticide in meerkats.
23. When is punishment effective and when is it not effective? How do the cognitive abilities required for punishment differ from those required for reciprocal altruism?
24. Why stick around and help if you are only going to be punished? Give an example and a hypothesis. How would you test your hypothesis?
25. How do sanctions work in soybeans?
26. Bshary and colleagues designed an elegant device for testing clearner fish behavior. Think of something to test with this apparatus that is biologically meaningful. What is your hypothesis and what is the test?
27. Compare and contrast cooperative breeding in Seychelles warblers, long-tailed tits and superb fairy wrens. What variables are important? Make a table with variables down the side and species across the top and fill in the cells.
28. What is territory saturation and how does it relate to cooperative breeding?
29. What changed Komdeur’s mind about cooperative breeding in Seychelles warblers?
30. What are the advantages and disadvantages of working on an island population?
31. Why are Seychelles warblers so drab when most North American warblers have colorful males? How would you test your hypothesis?
32. How can you tell if a behavior is voluntary helping, helping due to punishment, or manipulative deception? Give examples with your explanation.
Chapter 13
1. How does kin selection explain the evolution of exaggerated traits like those of soldier ants?
2. What is eusociality? How does it relate to sterile castes and totipotency?
3. Give three examples of why ants are so amazing.
4. What sex are worker ants? Worker bees? Worker termites? Worker wasps?
5. What is the life cycle of the ant Lasius niger?
6. What is the argument against genetic determination of the worker caste? How are workers determined?
7. What is the most likely evolutionary pathway for the evolution of eusociality, subsocial or parasocial? Describe them.
8. What is haplodiploidy? Diagram relatedness under haplodiploidy. What role does it have in eusociality? What complications come with considering male production?
9. Why and when do workers prefer a female-biased sex ratio? What ends up determining the sex ratio?
10. What is the monogamy hypothesis for eusociality? How would you disprove it?
11. What social insects are not monogamous? Do they disprove the monogamy hypothesis? Why or why not? What explains polyandry in social insects?
12. How do polyandrous social insects differ from monogamous social insects?
13. What is the life insurance hypothesis for eusociality? Give an example.
14. What is the fortress defense hypothesis for eusociality? Give an example.
15. If you encounter an unknown eusocial species, what data would you want to collect to determine if it is more likely to be a life insurer or a fortress defender?
16. What are social shrimp? Describe their life cycle. Why are they social?
17. Discuss sociality in aphids. Which ones are social? When does fortress defense occur? What other kinds of sociality do they exhibit?
18. Compare and contrast fortress defenders and life insurers along the lines of table 13.2. Do these traits all have to go together? Can you think of another way of organizing natural selection on social traits?
19. Thoroughly discuss food issues and sociality. Come up with a hypothesis and a test for it. The hypothesis need not be comprehensive to all foods and social behaviors.
20. How does food distribution impact sociality in naked mole rats? What is the evidence? Might this hypothesis also work for social insects? Why or why not?
21. Why is there conflict between workers and queen(s) and among workers?
22. What sex ratio are queens favored evolutionarily to prefer? What does this include?
23. If males and females are of equal size, what sex ratio are workers expected to prefer? Why?
24. What sex ratio are males expected to prefer? Why is there so little attention paid to male preferences in social insects?
25. What is the Trivers Hare hypothesis for sex ratios? What problems are there with the argument?
26. What is a split sex ratio? If a species has a split sex ratio, who is likely to be in charge, the workers or the queen?
27. Why and when does natural selection favor specializing on one sex or the other instead of producing a certain mixed sex ratio?
28. What does Sundstrom consider to be the factors driving sex ratio in Formica truncorum?
29. How can workers tell how many times their queen mated? What is the evidence for this hypothesis?
30. How could the workers change the sex ratio? How could the queen change the sex ratio?
31. What is the evidence that queens control the sex ratio in fire ants?
32. What is the tie between all these studies of sex ratios and kin selection?
33. Relate sex ratio conflict to who produces the males, the workers, or the queen.
34. What is worker policing? When does it occur?
35. Give a numerical example of worker policing, when it is favored and when not, assuming the queen mates once in some colonies and an infinite number of times in the other kind of colony.
36. When do workers agree with the queen on male production and why? Give an example.
37. Why would a worker or a queen lay an egg if another worker or the queen was just going to eat it?
38. How did Wenseleers and Ratnieks use the comparative method to examine the relationship between mating and policing predicted by kin selection?
39. What is a superorganism? What are the pros and cons of viewing the colony as a superorganism?
40. What are the differences in sociality between social insects and social vertebrates?
41. Why is lifetime monogamy important in insects and why does it not occur in vertebrates?
42. What are the ecological differences in sociality in insects and vertebrates? Might fortress defense or life insurance be more important in vertebrates? Give an example.
Chapter 14
1. Signals pervade animal behavior. DKW follow the definition that a signal is a feature of one individual that changes the behavior of another, the receiver. Give an example of a signal and use Tinbergen’s four approaches to show how you might understand the signal.
2. How does potential conflict between sender and receiver differ?
3. How could potential conflict between sender and receiver lead to an arms race? Why can’t senders win the arms race?
4. How do highly cooperative signals differ from more competitive ones? Consider both honesty and exaggeration.
5. What is the difference between a cue and a signal? Give an example of each.
6. What are the strengths and weaknesses of Susan Riechert’s study on spiders to explore signaling?
7. There are three hypotheses for how signals are kept honest: 1. An index signal is hooked to the trait it measures; 2. A handicap is a signal that is costly to fake, more costly for weaker condition individuals. 3. Honesty could be maintained by common interest, making faking unlikely. Compare and contrast these hypotheses and suggest ways of testing them.
8. How do animals assess each other’s size? In what way is this related to signaling? Give a hypothesis and think of a way to test it.
9. Why in an experiment might a frog try to displace a male it thinks is smaller because of his croak even though he can see him? Is this a flaw or an advantage of the experiment and why?
10. Why in figure 14.5 on page 403 do you think the researchers use vocal tract length in centimeters as the response variable, but show body weight as a log and reproductive success as a relative measure?
11. Under what mating system would you predict signals by males to be most honest? Why? How would you test your hypothesis?
12. Why are signaling traits likely to evolve rapidly?
13. What is the handicap principle for signal evolution? Why might ornaments be cheaper for high quality individuals?
14. What is a status badge? How do they compare with things like call pitch as signals of quality?
15. What is the difference between an index and a handicap in stalk-eyed flies? How did Cotton test the difference?
16. What is quorum sensing? Why release different molecules at high density? Why is it likely to evolve only in cell groups of close relatives? What did Diggle’s experiment show?
17. Why and why do non-relatives cooperate?
18. When is a signal dishonest? How do they evolve? Why should their evolution be common? What keeps signals honest?
19. What are alarm calls? What are their costs and benefits and to whom do the costs and benefits accrue?
20. Make a chart categorizing signaling according to a system you devise. Include examples.
Chapter 15
1. Give three advantages and disadvantages of the gene-centered view of natural selection and do the same for the individual-centered view. Give an example of a problem best approached by each view.
2. What is evolution by natural selection?
3. When do genes conflict with their carriers? Give an example.
4. What is a major evolutionary transition? What factors favor them? Give 3 examples.
5. How are optimality and ESS models used in behavioral ecology? Why is this approach robust to common criticisms?
6. What is the phenotypic gambit and why is it useful? Give an example.
7. Are organisms optimally adapted to their environment? Why not?
8. What are the similarities and differences between the new group selection and kin selection? Give an example.
9. If some kinds of group selection are similar to kin selection and therefore can happen, how about species selection? What is it and what must be shown for it to work?
10. What is the difference between a how question and a why question? Give an example of a problem approached by each.
11. Discuss the historical steps in the dung fly example. How have they changed?
12. Why does behavioral ecology matter? Give two examples in more detail than the list on page 439.
13. If you should remember one important thing from the course, what do you think it should be and why?
Davies, Krebs, West, An introduction to behavioral ecology
Get back to course page
Chapter 1
1. Starlings choose foraging sites to be in a group or not, to eat certain foods, and when to return to chicks. They also choose nest site, number of chicks to have, a mate, and how hard to work at caring for the chicks. Categorize these choices according to a sorting you devise, into two categories, not necessarily of equal size.
2. What are Tinbergen’s four questions? How do they differ? How are they similar? Give an example of each of the four that you would ask for a specific organism, perhaps the starlings.
3. What are all the ways relatedness impacts social interactions in lions? How does it vary with sex and age? Make a diagram.
4. What is the difference between proximate and ultimate causation? What is causation?
5. Why do female lions come into estrus synchronously? Think of at least two hypotheses. How might you test them?
6. Why do male lions kill cubs? Why do females mate with their cubs’ assassins? How would you test your hypothesis?
7. What are the key requirements for natural selection according to Darwin and what are they according to the genic view? What are the differences? What is the advantage of the gene-based view?
8. Why do we focus on differences when we study adaptation?
9. In Drosophila there are rovers and sitters. How do they differ? What role does the environment play and what role do genes play? What maintains the polymorphism?
10. How might understanding the pathways involved in foraging expression help understand how the gene works in flies and honeybees?
11. Why might coat color polymorphism be common?
12. Why might blackcaps vary in migratory behavior? Think of hypotheses for all four of Tinbergen’s approaches.
13. What is Wynne-Edwards hypothesis of group selection? What evidence did he think supported it? What is the problem with the idea?
14. What is Lack’s hypothesis? What did its tests at Wytham Woods near Oxford show? Why is this important?
15. What are all the factors that need to be considered in clutch size experiments? Graph it.
16. What are the tradeoffs between survival and reproduction? Graph it. What is an individual surviving for?
17. Why do some magpies produce large clutches?
18. What is a genotype? What is a phenotype? Which changes most rapidly with climate change? Give an example.
19. What is phenotypic plasticity? Why is it important? Give an example.
20. What is the story about English and Dutch great tits and breeding time? Which population might go extinct first?
Chapter 2
1. What do researchers do before they begin to generate and test hypotheses? Why might observation and hypothesis generation go together?
2. What are the three ways DKW say you can use to test hypotheses? List strengths and weaknesses of each.
3. Give the reasoning steps in the logical order that Darwin used to argue that mammal skull sutures did not originate to facilitate birth.
4. Table 2.1 compares the black-headed gull with the kittiwake for a number of traits. Use this information to generate a hypothesis. It is ok to use the one in the book. Which variables are responses and which are independent? Give the logic for a prediction for each variable. Which ones are least related to your main hypothesis? Why?
5. What is the problem with comparing black-hooded gulls and kittiwakes?
6. What is Crook’s argument about weaver birds, diet, coloration, and habitat? What are its strengths and weaknesses? How would you go about disproving it?
7. Why did Crook only consider weaver birds? Was this a good idea?
8. Compare and contrast Jarman’s study of African ungulates with Crook’s of weaver finches.
9. What are the main problems with these early comparative studies?
10. Why is it best to think of as many possible hypotheses as you can before beginning a study?
11. What if you think of a new hypothesis in the middle of a study? What should you do? What should you be careful of?
12. How might we distinguish cause and effect in any of the early comparative studies? Why is it important to do so?
13. Why were the advances in the comparative method by Clutton-Brock and Harvey so important? They are: 1 Treat variables as continuous not categorical; 2 They considered alternative hypotheses and used multivariate statistics on ecological variables; 3 They used genera as data points not species.
14. What are confounding variables and how do you reduce problems they cause?
15. What are some hypotheses for sexual dimorphism? How would you test one of them?
16. What is a phylogeny, how is it constructed, and why are phylogenies important?
17. How can you tie a phylogeny to actual time? Compare molecular clocks and fossils.
18. What are independent contrasts and why is this so important? What improvements did they make?
19. What more can we learn if we know the actual order that traits arose? Use primate sexual swellings as an example.
20. One of the biggest problems with experiments in animal behavior is that animals must be able to respond to the differences tested in the experiment. They will not evolve a new response just because you introduce a new condition. What would you do to take this into account in designing an experiment?
21. Critique the egg removal example in oyster-catchers and black-headed gulls using what you have learned in this chapter
Chapter 3
1. How many larvae should a starling carry back to the nest? What variables are important in determining this answer? Graph it.
2. What did Kacelnik’s experiment do that could not be done with natural feeding?
3. Why do bees return to the nest before they are full?
4. What is the marginal value theorem? Why is it useful? Give an example with a graph.
5. How long should male dungflies spend copulating? How do they know? Would your prediction change if the male knew he was the first, second, or subsequent mate?
6. What besides mating might a male dungfly do to increase his paternity?
7. What differences in male behavior would you expect depending on if he was in a dense patch with lots of males or in a sparse patch with few? How does this vary depending on if males or females or both are dense or scarce?
8. Compare and contrast the use of the marginal value theorem to explain starling foraging and dungfly mating. How does frequency dependence impact each?
9. What did Schmid Hempel show with weights on the backs of bees? What was the currency of measurement. Why is this a good currency and why is it a bad one?
10. Why does currency matter in cost-benefit analyses?
11. Why don’t shore crabs prefer to eat large mussels? What do you think would change if the crabs were offered two species of mussels that different differed in the relationship between size and hardness? What are all the variables needing consideration? Design an experiment to test your hypothesis.
12. Use the model from Charnov in Box 3.2 to predict how a predator should choose prey. Put in some values, draw a graph and say what you would do to test the model.
13. Describe and discuss the test of the prey handling model in great tits and worms of two different sizes. What might you do to improve the experiment?
14. What did Lima do to study learning while foraging in downy woodpeckers? What kinds of organisms are amenable to experiments like this one?
15. Foraging currencies include rate of food intake, efficiency, and risk of starvation. Can you think of others? Compare and contrast these. Which is likely to be important for any given bird species?
16. How much less food might an organism accept for a more certain delivery? What does this depend on? Why might time of day matter? How about predation risk?
17. Why did temperature change yellow-eyed junco foraging decisions? Why might bumblebees be less risk prone?
18. Why would a songbird in winter carry less fat than it could? What do you predict about changes during the day?
19. Why did great tits lose weight after sparrowhawks returned to Wytham Woods?
20. What is the argument that birds that scatter hoard seeds have to remember where their own seeds are? How was this tested in willow tits?
21. How did Sherry and colleagues show that marsh tits actually remember where seeds are stored?
22. What do London taxi drivers have in common with Clark’s nutcrackers? Why do you think hippocampus volume and the associated impact on memory is a plastic and not a fixed trait evolutionarily speaking? How would you test your hypothesis?
23. Where would you expect larger hippocampus, Alaska or California? Why? Think of some other contrasts to make predictions.
24. What is the difference between episodic memory and procedural memory?
25. What does allowing birds to hide both worms and seeds tell us that the seed only experiments did not?
26. Why does a bird care if it has been observed hiding food? What do scrub jays do when observed? What do you expect of other birds?
27. Why might dominant birds be less likely to move their caches than subordinate birds? Under what circumstances do you expect birds to share their caches?
28. Why would a scrub jay store dog food in the pine nut room and vice versa? What are the strengths and weaknesses of the food choice experiments like this done under artificial circumstances?
29. What kinds of intelligence and foresight do these learning experiments demonstrate? Why might animals be more like people, or people more like animals? What do you think a human would do with the dog food/pine nuts experiment (perhaps changed food items)?
30. What most intrigues you about bird intelligence? Design an experiment that would test a hypothesis in this area using insights from the experiments in this chapter.
31. Why don’t the squirrels of Lima’s experiment learn that you won’t hurt them and stay at the picnic table? Why should this behavior be any less plastic than some of the caching behaviors discussed earlier in the chapter?
32. Design a semester long experiment on squirrels and picnic tables. Assume you can tell the squirrels apart, perhaps with spray paint.
33. Why would a stickleback ever choose to forage where food is less dense?
34. Compare the kinds of foraging behavior experiments researchers do with birds vs. fish. What is easier with fish? What is easier with birds? What is the same and what is different.
35. Give three examples of social learning. If social learning for foraging is so effective, why is it not more universal? What does it require? What are its costs and benefits?
36. What is the difference between social learning and teaching? Give the three necessary attributes of teaching. Why does it not require a large brain? Give examples.
37. Why shouldn’t meerkats just skip eating dangerous scorpions? What risks do adults incur in teaching the pups how to eat scorpions?
38. How can we tell when animals or humans operate from simple behavioral rules rather than complex cognitive mechanisms?
39. What is an optimality model? What are its strengths and weaknesses? Give examples.
Chapter 4
DKW 4 Study Questions Predator Prey
1. How does the red queen hypothesis apply to predator interactions with prey? What exactly is the red queen hypothesis?
2. Give three predator actions and adaptations and the evolved responses of the prey. Can you think of other things than are in table 4.1?
3. Discuss the evidence the Daphnia (water flea) example gives for predator prey cycles. Design an experimental evolution study that would get at the same thing. What organisms would you use? You have only 2 years to do the study.
4. Describe the blue jay experiment on crypsis. Why do you think it was all right for the investigators to use blue jays that were simply shown photos of the prey?
5. Underwing moths have cryptic forewings and scary underwings. Why are the forewings more variable than the underwings? How would you test a hypothesis on this?
6. What is a search image? What experiment did Marian Dawkins do to show that this mattered in chickens?
7. Summarize the studies on bird predation and moths. What is looked at? What do the experiments have to be careful about? What are the big conclusions?
8. When should the great tits ignore straws with mealworms in them? How does this experiment compare to the ones Stephens and Kamil did with blue jays?
9. What is the difference between masquerade and crypsis? Which do you think is likely to be more effective? Which is more likely to lose its power over time with the same individuals? Why?
10. Why are the dendrobatid frogs that eat ants brightly colored? How would you test your hypothesis? (Don’t even think about feeding them something different and letting them “evolve” change.)
11. Come up with a theory on bird intelligence and diet, along with a test.
12. Why are gregarious locusts (grasshoppers) brightly colored, and solitary ones of the same species not?
13. How did distastefulness and bright coloration evolve? What is the problem? Why might family groups be important?
14. What are Müllerian and Batesian mimicry? Which do you expect to have tougher skin? Give examples of the two kinds of mimicry.
15. What are the tradeoffs between temperature and color, and between offspring production and toxin metabolism? At some level, we could say everything is about tradeoffs. Think of some other situations in this chapter that probably involved tradeoffs and give two examples and state why you think tradeoffs are involved.
16. What is the evidence for a tradeoff between crypsis and territoriality? How might it be moderated?
17. What happened to guppy coloration with increasing predation? Why do you think the variability existed in the population to make the selection experiment so successful?
18. Describe nest parasitism by the common cuckoo, Cuculus canorus, in Europe. Why does the mother eject only one egg when she parasitizes, even though the cuckoo chick will subsequently eject the remaining host eggs?
19. Why can’t cuckoo hosts tell that the cuckoo baby is not their own?
20. Why are some cuckoo hosts better at recognizing cuckoo eggs? What do the cuckoos do about it? Are these evolved or plastic responses? How would you test your hypotheses?
21. When we say “hosts evolve to reject cuckoo eggs,” what exactly are the steps involved? List them, beginning with hosts accept cuckoo eggs.
22. What does signaling theory tell us about cuckoo egg acceptance and rejection? Think about applying signaling theory, as described in box 4.2, to a non-cuckoo example in the chapter.
23. Compare and contrast how natural selection is likely to work on predator-prey situations that evolve crypsis, those that involve warning coloration, and cuckoos.
Chapter 5
1. Frequency dependence is a very important concept in evolutionary biology. What is it and why is it so important?
2. What is an Evolutionarily Stable Strategy (ESS)? What do you have to know to formulate one? Why are they not necessarily the best for all or even on average?
3. Deascribe Hawk Dove in detail and what an ESS is under Hawk Dove.
4. In what ways is hawk dove too simplistic? How would you modify it?
5. What is the ideal free distribution between rich and poor habitat? In what ways is it unrealistic? Give examples and graphs.
6. What is natural and what is not about Manfred Malinski’s experiments on cichlid feeding?
7. Why would a male dungfly ever leave a female when he is mating? Howe does this differ from the spider example? If you came a cross a mating pair what variables would you need to collect to understand when the female and male might desire to end the relationship? Keep in mind that most arthropod males deliver sperm gradually, not all at once.
8. How might territoriality at a resource that is attractive to females, like a dung pat, or a pond, change mating time and choice variables?
9. Why is the concept of economic defendability important? What variables and what relationships among them are important?
10. What is the story on pied wagtail territory sharing? How would you rule out the hypothesis that there is no active sharing, but just different costs and benefits to chasing off intruders?
11. What is the concept “best of a bad job?” Is it useful or not? When and why? To whom does it apply?
12. What determines when producers or scroungers or any two alternative strategies have an equilibrium, as opposed to one always being worse than the other? Do the differences in strategies depend on there being differences in the individuals? Explain.
13. Discuss ruddy turnstones and spice finches.
14. What is a strategy and what is a tactic? Why are both necessary terms? Give an example.
15. Why do some natterjack toads refrain from calling/ How does this differ from the horseshoe crab?
16. Natterjack toad males, if they survive, eventually grow to be large enough to be callers. By contrast, Onthophagus beetles either have horns or don’t, fixing their strategy for life. Does this matter for understanding the two strategies? Why the difference?
17. Describe the Onthophagus story in detail. What do the Hunt and Simmons experiments add? How did Emlen show the trait had a genetic basis? Why are beetle horns a more tractable system than calling frogs for study in alternative strategies?
18. Why should genetically determined alternative strategies have, on average, equal success? Does this mean most alternative strategies are environmentally, not genetically determined.
19. What is frequency dependent selection? How does it apply to alternative strategies? What else might it apply to?
20. Discuss polymorphism in ruffs, Philomachus pugnax. What might help keep three morphs stable? Is this likely to be the same in isopods, Paracerceris sculpta? Why do the female mimic males have such huge testes? How would you test your hypothesis?
21. What are the three strategies of side blotched lizards, Uta stansburiana and why do they vary in frequency? What is a rock/paper/scissors hierarchy and how does it differ from the previous stories like ruffs or beetles?
22. What is ESS thinking? Why is it important? How does it tie to the strategy/tactic difference? How does it tie to genes?
23. What is an animal personality? Give an example. How do they relate to strategies, tactics and ESS? Why is frequency dependence likely in animal personalities? How would you test your hypothesis?
24. Why, throughout this chapter have the behaviors of others been so important?
Chapter 6
1. What is the problem with the hypothesis that groups form to benefit the population or species? How would you test this idea?
2. How does the dilution effect work in water skaters (water striders)? What would a figure showing the dilution effect look like? Are the effects similar or different in horses and monarchs?
3. How does the predator swamping hypothesis differ from the dilution effect? How do the groups differ? How would you tell which is the best explanation? Give an example of each.
4. What is a selfish herd? How are they organized? Give an example.
5. Make a chart of the hypotheses farvoing grouping as a defense from predators and what they predict. Use graphs.
6. Discuss vigilance, predation, and group size. What is the cost to vigilance and how might you measure it?
7. What keeps vigilance honest?
8. What is an information center?
9. At what life stages do animals group and how does this influence the costs and benefits of grouping?
10. Why would it ever be advantageous to attract others to a food resource you discovered?
11. What did the plastic pellets tell us about raven foraging?
12. What do schooling tradeoffs in guppies show? What is special about the Magurran study? What other studies show tradeoffs in grouping?
13. What are the costs of grouping? What impact do these costs have on grouping?
14. What is an optimal group size? Work back through some of the examples and think about what factors contribute to optimal group size. How might you test your ideas?
15. How do the interests of the group and the individual play out in optimal group size? Does this lead to larger or smaller groups?
16. What is skew? How does it apply to grouping?
17. Why would a hungry animal ever refuse food?
18. How can groups make decisions apart from those of the individuals in them? How does this behavior evolve?
19. What kinds of evidence led Couzin and Franks to conclude that army ants have three rules: 1. That they follow pheromone concentration gradients; 2. That they go away from the colony without food, towards it with food, and 3. That outbound ants move out of the path of inbound ants? Do you agree with their conclusions? Why?
20. What are the strengths and weaknesses of using computer simulations to test hypotheses?
21. In fish schools what is the difference between a swarm, a torus, and a directional group? How does school organization change in the presence of a predator?
22. How can researchers show that fish do not count in determining the size of the group they join?
23. What is opinion polling and how does it work in animals? Give two examples.
Chapter 7
1. Why did Darwin feel he needed an additional theory, sexual selection? What are its two main components?
2. What is anisogamy? How might it have evolved? How do data from Volvocales support this hypothesis?
3. Why do protists, single-celled eukaryotes, lack anisogamy?
4. Why does Trivers view parental care as an analogous investment as a large egg? How does this affect how we think about sexual selection?
5. What’s more important for natural selection, the maximum reproductive rate as shown in Table 7.1, or some other metric? What other metric and why, if this is your answer.
6. Queller has two general reasons for why females should be more likely than males to take care of the young. What are they and how do the arguments go?
7. How does sexual selection explain sexual dimorphism? What conditions explain sexual dimorphism? Give examples.
8. Describe Malte Andersson’s experiment on widowbirds and indicate how it demonstrated female choice.
9. Why should there be a tradeoff between red color and tail length considering widowbirds and red bishops?
10. What are the likely differences in physical characteristics in males that offer females good resources vs. good genes? Give examples.
11. Compare and contrast longtailed widowbirds, sedge warblers, hanging flies, bullfrogs, and satin bowerbirds. Make a table.
12. How does Zahavi’s argument for handicaps work? Why might a handicap tell a female about the genetic quality of her mate. Give examples.
13. How did Marion Petrie use peacocks to test the good genes hypothesis? What exactly is the good genes hypothesis? What controls did she use?
14. What is the Hamilton-Zuk hypothesis? Why does it predict greater parasite loads on species with more colorful males? What is the relationship between male color and female choosiness within and between species?
15. Discuss the four key assumptions of the Hamilton Zuk hypothesis: 1) that parasites reduce host fitness; 2) that parasite resistance is genetic; 3) that elaborate ornaments signal parasite resistance; and 4) that females prefer males with the most elaborate signals.
16. Describe the Milinski and Bakker experiments and indicate what elements supported which paths of the Hamilton Zuk hypothesis. How does the MHC complex play into it?
17. Discuss female ornamentation and its relation to sexual ornamentation theory. When do you expect both sexes to be ornamented and when just females?
18. How might you show that ornamented females are not just co-selected nonadaptive correlates of male characteristics, but selected in their own right?
19. What are the similarities and differences between sperm competition and precopulatory sexual selection?
20. What are all the reasons a female might copulate with multiple males? How would you test your hypothesis?
21. Critically examine the hypothesis that extrapair copulation opportunities drive coloration in male birds.
22. Why do you think the social mating system in birds was not correlated with plumage dimorphism in birds?
23. Why should mating with multiple males lead to greater offspring survivorship? Why not just pick the best guy and mate with him?
24. In what sense are relations between mating males and females an arms race and in what sense are they not?
25. What variables come into play on forced copulations? What other kinds of sexual conflict are there?
26. If females are not faithful, why do males ever care for young? How would you test your hypothesis?
27. Why would female spines and male abdomen shape ever coevolve?
28. What do males do to increase their paternity when females mate multiply?
29. What are parasperm and how do they evolve? How do they differ from accessory gland proteins?
30. What is the significance of testes size?
31. Are postmating conflicts more important to the male or the female? What are the consequences of the differences?
32. Discuss duck genitalia and arms races.
33. Diagram William Rice’s experimental evolution experiment with Drosophila and mate conflict.
34. What is antagonistic coevolution?
Chapter 8
1. Compare ad contrast conflict between male and female parents, conflict among siblings, and conflict between parents and offspring, over parental care. Consider genetic relatedness, probability of relatedness, costs and benefits to each party and other variables that might be relevant.
2. Given that parental care is so rare in organisms, including most animals, why does it ever evolve? (What is an animal?) How would you test your hypothesis?
3. What can parents do to increase the survival of their young? List as many ways as you can think of. How does this represent tradeoffs in numbers of offspring?
4. Why, when, and where do males care? Why, when, and where do females care? (By care we mean care for young.
5. List parental care types in invertebrates, fish, amphibians, reptiles (excluding birds), birds, and mammals. What are the similarities and differences and why have they evolved?
6. How does whether fertilization is internal or external to the female impact parental care? Give three hypotheses and how you would test each.
7. What is parental investment according to Trivers? What behaivors is it made up of? What is lifetime parental investment?
8. What are parental investment tradeoffs within broods according to Lack? How does this influence parental investment between broods?
9. What are the different things that go into a parent maximizing lifetime reproductive success? Be complete.
10. What is more valuable, current or future brood? Why? Does your answer vary with age or increasing or decreasing population size?
11. Figure 8.2 shows the relationship between costs to parental investment that increase linearly, and benefits to the offspring that level off. Parents should choose to invest where costs and benefits are fartherst apart. Why are benefits convex and costs linear? Under what circumstances might these curves take different shapes?
12. What did Ghalambor and Martin predict about risk taking in response to predators in the temperate and tropical regions? Was their hypothesis supported? Can you make other similar predictions based on other circumstances that might affect adult vs. brood survivorship?
13. What hypotheses did Balshine and Earn test on St. Peter’s fish? What did they find? What other variables might they have considered and why?
14. Why would a parent ever eat their young? Why might this be particularly common in fish? How would you test your hypothesis?
15. Some females lay larger, better eggs when mated with more attractive males. Under what conditions or mating systems would you expect this to evolve?
16. Sexual conflict between males and females that have mated occurs over who should provide parental care and how much to provide. Each parent’s staregy depends on what the other does. This is not necessarily highly variable. Discuss what things you would want to know to predict the outcome of this conflict in a species.
17. If one parent does not give enough care, why does the other parent not compensate fully?
18. Why do you suppose that great tit parents feed more when there was a begging speaker? Why would the other parent also increase its effort, even not hearing the speaker?
19. Diagram and discuss the role of genetic relatedness in parent offspring conflict.
20. What is siblicide? What circumstances favor its evolution? What circumstances increase its occurrence in a given year?
21. Why do chicks beg loudly? What influences their begging? Why are parents so susceptible to it? What do coot studies show?
22. What is the evidence for parent offspring conflict? How do you distinguish it from normal developmental maturation? Give examples.
23. What are the costs and benefits of synchronous vs. nonsynchronous brooding in birds? Give an example.
24. Why should it matter which parent you inherit a gene from? Explain genomic imprinting in insulin like growth factor.
25. Why should begging levels differ among nests? How did Kilner show this? Discuss co-evolution of begging in canaries and burying beetles.
26. What is a maternal effect compared to a genetic trait? Give an example.
27. What is a brood parasite? Give examples. How much should they beg?
28. Compare and contrast cowbird and cuckoo behavior. Why the difference? How would you test your hypothesis?
29. Why should parents’ interests or their own young’s interests ever differ?
Chapter 9
1. What is meant by a mating system? Explain the different kinds. What kinds of sexual reproduction are apparently left out of table 9.1?
2. Why does resource distribution (food, nesting sites) influence breeding system? Describe with a figure and two examples.
3. What is the mating sex ratio? Why does it vary? Give examples.
4. What do the grey sided voles and the blue head wrasse studies show? What do they have in common and how do they differ? How might you expand either study?
5. Compare and contrast the four kinds of mammalian mating systems: 1) females solitary:range defensible by male; 2) females solitary: range not defensible by male; 3) females social, range defensible by male; 4) females social: range not defensible by male. How would you test the hypothesis that female range determines the mating system?
6. Draw a figure or figures of male and female interests and how they come together in mating systems.
7. What is a lek? Where do they occur? Why do you think they are rare? In what ways could they benefit males? In what ways could they benefit females?
8. Compare and contrast the five hypotheses for leks (hotspots, predation reduction, increase female attraction, males aggregating around good males, and female mate choice). The book implies that different hypotheses work best for different organisms. What data would you want to collect for a comprehensive hypothesis on lekking? What do you think the most general hypothesis is? How would you test it?
9. What is phylogenetic inertia? One example is that mammals have females predisposed to care for young with milk. Do birds have anything analogous? Compare and contrast breeding systems in birds and mammals with phylogenetic intertia in mind.
10. Why are so many birds monogamous? What is the difference between social monogamy and genetic monogamy? Why do they differ in so many bird species? How would you test your hypothesis?
11. Look at part B of Fig. 9.8. that shows red winged blackbird male territories, their paternity in the brood they raised, and their extra-pair paternity. What causes the patterns? Do males mate extra-pair their closest neighbors? Are some males preferred as mates by everyone? Do males with the greatest extra-pair success also have the greatest success with their own mate. Draw a table with territory size, within pair success, extra pair success, and distance (measured in territories) of extrapair success to help with your conclusions.
12. What is resource defense polygyny? When would a female choose to be the second female on a male’s territory when she could be the first female on a different male’s territory? Use a figure and an example in your answer.
13. What are the costs and benefits of polygyny? For females? For males? Give examples.
14. What do we learn from experiments vs. comparative method on the evolution of polygyny? Give examples from each technique.
15. In what way is the polygyny threshold model like the ideal free distribution? What are the strengths and weaknesses of models like this? Give an example.
16. Why might a female pied flycatcher ever become the second female? Do you think they know there is someone else? What would you do to be sure he didn’t have another mate? How would you test your hypothesis?
17. What is the sexy son hypothesis? What are its weaknesses?
18. How would you determine whether or not it is deception or lack of single males that is involved in polygynous mating in the pied flycatcher? What clever test did Alatalo do? Apply this also to another bird species you have read about.
19. Discuss the mating system of the dunnock, Prunella modularis. Why is it so complex compared to other birds? Why do females ever mate polygynously if polyandry is a more successful strategy?
20. What kind of limitation is the clutch size of 4 in shorebirds? Why does it lead to polyandry? Give examples.
21. How important is the ability of males to desert first in some systems in determining who cares for the babies? What other reasons might males care less than females? How would you test your hypothesis?
22. Can you put the three themes of mating systems (life history constraints, ecological factors, and social conflicts) into a broad framework that will predict each system? Consider also which ones are phylogenetic constraints and which are more plastic. Is Table 9.3 helpful in your thinking, or do you have another plan?
Chapter 10
1. What does dioecious mean? What organisms are dioecious? How do their decisions regarding sex compare to those of sequential hermaphrodites?
2. How is sex determined in turtles, wasps, mice, and blackbirds? What difference does sex determination make for sex allocation?
3. What is Fisher’s theory of equal investment in the sexes? What brings a biased sex ratio, say in a small population, back to equality? Is the process likely to differ between turtles and mice? How?
4. What exactly did Alexandra Basolo in 1994 do with the southern platyfish Xiphorus maculatus to support Fisher’s theory of equal sex ratios?
5. How does the equal sex ratio argument change if males are twice as costly to produce? Costly to whom?
6. What is local resource competition? Under what circumstances does it impact sex ratios? Why do males and females sometimes disperse different distances? Towards which sex is the sex ratio biased when it is biased because of local resource competition?
7. Why are sex ratios so biased in army ants? Is the sex investment ratio also biased?
8. What is local mate competition and how is it similar or different from local resource competition? Explain the reasoning behind two arguments for local mate competition, 1) that males devalue each other, and 2) that, under inbreeding, a female-biased sex ratio provides males with more sisters as mates.
9. What precondition for equal sex ratios is generally violated under local mate competition?
10. Why do female parasitoid wasps produce a less female biased sex ratio when laying eggs in a patch in which another female has already laid eggs?
11. What is the logic behind Pen and Weissing’s argument that in species with helpers at the nest, groups with helpers should produce the non-helping sex and groups without helpers should produce the helping sex?
12. Describe in detail the experiment of Komdeur using Seychelles warblers to study local resource competition and local resource enhancement. When and why do female Seychelles warblers produce 2 eggs? What other numbers do they lay? Why the variability?
13. Under what circumstances are sex ratios less adjusted to resources, according to Griffin? What is her evidence?
14. What is a meta analysis? What are its strengths and weaknesses? How can meta analyses find significance out of a whole set of studies that are insignificant on their own?
15. What is the Trivers-Willard hypothesis? What are the assumptions? Is the hypothesis supported? Discuss red deer. How did Sheldon modify the hypothesis to apply it to blue tits? What did he find in blue tits?
16. Under what circumstances should males emerge first in species with environmental sex determination?
17. Discuss sex change. Where does it occur? What sex is likely to emerge first? Why? Give 3 examples.
18. What is sex ratio distortion? Discuss driver X and Wolbachia and give examples of their action in 2 animals.
Chapter 11
1. Explain the definition of altruism, that a behavior is altruistic if it is costly to the personal reproduction of the actor that performs it and beneficial to another individual. What exactly does it mean?
2. How does Hamilton’s classification of social behaviors into mutually beneficial, altruistic, selfish, and spiteful work in terms of gain to actor and recipient? Can you give an example of each kind of behavior?
3. Why would you count parental care as altruism? In what sense is it not?
4. What exactly is relatedness? Diagram relatedness between cousins, siblings and parents and offspring according to the method in the box on page 11.2.
5. What is inclusive fitness? Why is it tricky to define? How do you avoid double counting? Why is inclusive fitness so hard to measure, even if you are careful not to double count?
6. What is kin selection? What is its relationship to inclusive fitness?
7. Explain Hamilton’s Rule, rb-c>0 and give an example. How does this work at the level of the gene?
8. How many extra offspring would it take to favor a gene which causes you to help your mother raise your full siblings and not reproduce yourself?
9. What did Paul Sherman figure out about ground squirrels? How do males differ in whom they interact with compared to females? What is the result of this behavior? Discuss alarm calls and infanticide.
10. Describe the black-tailed prairie dog studied by John Hoogland. How do they differ from Beldings ground squirrels in social structure and altruism?
11. Why would a male turkey help another achieve matings? How does this study support Hamilton’s rule?
12. What is a greenbeard gene?
13. What is kin recognition? Why is it important? What is the armpit effect?
14. Why are social amoebae so cool? What is their social cycle? How did the researchers show they recognize kin?
15. What is the advantage to a simple kin recognition rule, like if they are in my nest, they are my relatives? What is the cost? Give an example.
16. How does kin selection explain siderophore production? What is a siderophore? Who produces them and why? Draw a picture.
17. What kinds of population structure favor siderophore production?
18. How do you measure relatedness in microbes?
19. Discuss cannibalism in tiger salamanders. What is so interesting about it?
20. What are all the hypotheses that Pfennig et al. tested for tiger salamander cannibalism? Why did they settle on kin selection?
21. What is spite and when might it evolve?
22. What color would the belly of the actor be in B11.5.1 where A is ¾ green, and B is ¼ green, and C is ½ green and the population is ½ green? Why is this figure useful in explaining relatedness?
23. What are bacteriocins? In what sense are they kin selected?
Chapter 12
1. What do they mean when they say cooperation is not just about kin selection? Does this disprove kin selection? Why or why not?
2. Compare and contrast the requirements for kin selection, by-product benefits, reciprocity, and enforcement. Give an example of each. What kinds of cooperation are not covered by any of these? What kinds overlap?
3. What is cooperation?
4. Why do they exclude a one-way benefit from cooperation? Give an example.
5. Think about the similarities and differences beteen service mutualisms like clearner fish and legume-rhizobia ones as compared to microbial secretory mutualisms. Compare and contrast.
6. What is a free rider? Give an example. What is a free rider in the human system of prisoner’s dilemma? Why does it make cooperation unstable? What is the solution?
7. What is direct fitness? What is indirect fitness? Give examples.
8. Figure 12.2 is a good breakdown of the kinds of cooperation. Return to it as you work through the chapter. The elements in the table are not all analogous. Some involve recognition. Others involve power. Others involve self-interest. Others involve ecology. Think about how you might classify these and other elements. Come up with a chart that is more clear to you on these variables. Give examples.
9. What did Ben Hatchwell show with long-tailed tits?
10. What is Hatchwell’s argument on why the tits show direct or indirect fitness, but not both? Do you agree? Why or why not?
11. A study of the superb fairy wren did not show any increase in chick mass from helpers. What instead were the benefits? What exactly did the mothers do differently and what were the consequences?
12. How does game theory apply to cooperative hunting? In what sense is it frequency dependent?
13. Why do unrelated ants cooperate? Why do they have fights to the death when the cooperative hunters in the ESS example keep cooperating?
14. Use group hunting as an ESS, cooperative nest founding in ants, OR group augmentation by meerkats to explain by product benefits. What are some other by product benefits? Is this cooperation? How does it compare to other kinds of cooperation?
15. Why be a meerkat baby sitter? What are the costs, benefits, and alternatives? How does it differ between the sexes?
16. Why in meerkats is it hard to separate direct and indirect fitness effects? Discuss this issue for two other animals that have some form of cooperative breeding.
17. What is reciprocity? What are the requirements for it to happen, cognitive and otherwise.
18. Give some examples of reciprocity in humans. Why don’t people cheat more often? When do they cheat?
19. Discuss blood sharing in vampire bats. Give a hypothesis and a test of it to best explain blood sharing. What data would disprove your hypothesis?
20. Explain mating in olive baboons. How has this behavior evolved?
21. What are the problems with animal examples that claim to support reciprocity?
22. Discuss all forms of infanticide in meerkats.
23. When is punishment effective and when is it not effective? How do the cognitive abilities required for punishment differ from those required for reciprocal altruism?
24. Why stick around and help if you are only going to be punished? Give an example and a hypothesis. How would you test your hypothesis?
25. How do sanctions work in soybeans?
26. Bshary and colleagues designed an elegant device for testing clearner fish behavior. Think of something to test with this apparatus that is biologically meaningful. What is your hypothesis and what is the test?
27. Compare and contrast cooperative breeding in Seychelles warblers, long-tailed tits and superb fairy wrens. What variables are important? Make a table with variables down the side and species across the top and fill in the cells.
28. What is territory saturation and how does it relate to cooperative breeding?
29. What changed Komdeur’s mind about cooperative breeding in Seychelles warblers?
30. What are the advantages and disadvantages of working on an island population?
31. Why are Seychelles warblers so drab when most North American warblers have colorful males? How would you test your hypothesis?
32. How can you tell if a behavior is voluntary helping, helping due to punishment, or manipulative deception? Give examples with your explanation.
Chapter 13
1. How does kin selection explain the evolution of exaggerated traits like those of soldier ants?
2. What is eusociality? How does it relate to sterile castes and totipotency?
3. Give three examples of why ants are so amazing.
4. What sex are worker ants? Worker bees? Worker termites? Worker wasps?
5. What is the life cycle of the ant Lasius niger?
6. What is the argument against genetic determination of the worker caste? How are workers determined?
7. What is the most likely evolutionary pathway for the evolution of eusociality, subsocial or parasocial? Describe them.
8. What is haplodiploidy? Diagram relatedness under haplodiploidy. What role does it have in eusociality? What complications come with considering male production?
9. Why and when do workers prefer a female-biased sex ratio? What ends up determining the sex ratio?
10. What is the monogamy hypothesis for eusociality? How would you disprove it?
11. What social insects are not monogamous? Do they disprove the monogamy hypothesis? Why or why not? What explains polyandry in social insects?
12. How do polyandrous social insects differ from monogamous social insects?
13. What is the life insurance hypothesis for eusociality? Give an example.
14. What is the fortress defense hypothesis for eusociality? Give an example.
15. If you encounter an unknown eusocial species, what data would you want to collect to determine if it is more likely to be a life insurer or a fortress defender?
16. What are social shrimp? Describe their life cycle. Why are they social?
17. Discuss sociality in aphids. Which ones are social? When does fortress defense occur? What other kinds of sociality do they exhibit?
18. Compare and contrast fortress defenders and life insurers along the lines of table 13.2. Do these traits all have to go together? Can you think of another way of organizing natural selection on social traits?
19. Thoroughly discuss food issues and sociality. Come up with a hypothesis and a test for it. The hypothesis need not be comprehensive to all foods and social behaviors.
20. How does food distribution impact sociality in naked mole rats? What is the evidence? Might this hypothesis also work for social insects? Why or why not?
21. Why is there conflict between workers and queen(s) and among workers?
22. What sex ratio are queens favored evolutionarily to prefer? What does this include?
23. If males and females are of equal size, what sex ratio are workers expected to prefer? Why?
24. What sex ratio are males expected to prefer? Why is there so little attention paid to male preferences in social insects?
25. What is the Trivers Hare hypothesis for sex ratios? What problems are there with the argument?
26. What is a split sex ratio? If a species has a split sex ratio, who is likely to be in charge, the workers or the queen?
27. Why and when does natural selection favor specializing on one sex or the other instead of producing a certain mixed sex ratio?
28. What does Sundstrom consider to be the factors driving sex ratio in Formica truncorum?
29. How can workers tell how many times their queen mated? What is the evidence for this hypothesis?
30. How could the workers change the sex ratio? How could the queen change the sex ratio?
31. What is the evidence that queens control the sex ratio in fire ants?
32. What is the tie between all these studies of sex ratios and kin selection?
33. Relate sex ratio conflict to who produces the males, the workers, or the queen.
34. What is worker policing? When does it occur?
35. Give a numerical example of worker policing, when it is favored and when not, assuming the queen mates once in some colonies and an infinite number of times in the other kind of colony.
36. When do workers agree with the queen on male production and why? Give an example.
37. Why would a worker or a queen lay an egg if another worker or the queen was just going to eat it?
38. How did Wenseleers and Ratnieks use the comparative method to examine the relationship between mating and policing predicted by kin selection?
39. What is a superorganism? What are the pros and cons of viewing the colony as a superorganism?
40. What are the differences in sociality between social insects and social vertebrates?
41. Why is lifetime monogamy important in insects and why does it not occur in vertebrates?
42. What are the ecological differences in sociality in insects and vertebrates? Might fortress defense or life insurance be more important in vertebrates? Give an example.
Chapter 14
1. Signals pervade animal behavior. DKW follow the definition that a signal is a feature of one individual that changes the behavior of another, the receiver. Give an example of a signal and use Tinbergen’s four approaches to show how you might understand the signal.
2. How does potential conflict between sender and receiver differ?
3. How could potential conflict between sender and receiver lead to an arms race? Why can’t senders win the arms race?
4. How do highly cooperative signals differ from more competitive ones? Consider both honesty and exaggeration.
5. What is the difference between a cue and a signal? Give an example of each.
6. What are the strengths and weaknesses of Susan Riechert’s study on spiders to explore signaling?
7. There are three hypotheses for how signals are kept honest: 1. An index signal is hooked to the trait it measures; 2. A handicap is a signal that is costly to fake, more costly for weaker condition individuals. 3. Honesty could be maintained by common interest, making faking unlikely. Compare and contrast these hypotheses and suggest ways of testing them.
8. How do animals assess each other’s size? In what way is this related to signaling? Give a hypothesis and think of a way to test it.
9. Why in an experiment might a frog try to displace a male it thinks is smaller because of his croak even though he can see him? Is this a flaw or an advantage of the experiment and why?
10. Why in figure 14.5 on page 403 do you think the researchers use vocal tract length in centimeters as the response variable, but show body weight as a log and reproductive success as a relative measure?
11. Under what mating system would you predict signals by males to be most honest? Why? How would you test your hypothesis?
12. Why are signaling traits likely to evolve rapidly?
13. What is the handicap principle for signal evolution? Why might ornaments be cheaper for high quality individuals?
14. What is a status badge? How do they compare with things like call pitch as signals of quality?
15. What is the difference between an index and a handicap in stalk-eyed flies? How did Cotton test the difference?
16. What is quorum sensing? Why release different molecules at high density? Why is it likely to evolve only in cell groups of close relatives? What did Diggle’s experiment show?
17. Why and why do non-relatives cooperate?
18. When is a signal dishonest? How do they evolve? Why should their evolution be common? What keeps signals honest?
19. What are alarm calls? What are their costs and benefits and to whom do the costs and benefits accrue?
20. Make a chart categorizing signaling according to a system you devise. Include examples.
Chapter 15
1. Give three advantages and disadvantages of the gene-centered view of natural selection and do the same for the individual-centered view. Give an example of a problem best approached by each view.
2. What is evolution by natural selection?
3. When do genes conflict with their carriers? Give an example.
4. What is a major evolutionary transition? What factors favor them? Give 3 examples.
5. How are optimality and ESS models used in behavioral ecology? Why is this approach robust to common criticisms?
6. What is the phenotypic gambit and why is it useful? Give an example.
7. Are organisms optimally adapted to their environment? Why not?
8. What are the similarities and differences between the new group selection and kin selection? Give an example.
9. If some kinds of group selection are similar to kin selection and therefore can happen, how about species selection? What is it and what must be shown for it to work?
10. What is the difference between a how question and a why question? Give an example of a problem approached by each.
11. Discuss the historical steps in the dung fly example. How have they changed?
12. Why does behavioral ecology matter? Give two examples in more detail than the list on page 439.
13. If you should remember one important thing from the course, what do you think it should be and why?