Chapter 10 Questions:
Male honey bees (Apismellifera) die when they mate for the first and only time, achieving suicidal monogamy when their genitalia are donated to the female. Try to explain the male’s suicidal mating behavior in light of the alternative hypotheses for male monogamy. What predictions follow from the different explanations you have considered? What data are required to resolve the issue?
2 In the European starling (Sturnus vulgaris), some males acquire several mates but do not assist them, whereas other males are monogamous and work together with their sole partners to rear their broods. Sometimes when there are two females nesting on a male’s territory, the first female to settle pierces her companion’s eggs with her beak (Reid et al. 2002). Why might she do so, and what kind of monogamy could result from her actions? Under what circumstances would the female’s behavior actually qualify as a form of parental investment?
3. The mimic poison frog (Ranitomeya imitator) of Peru is a truly monogamous animal, as revealed by genetic tests of offspring that are cared for by both parents (Brown et al. 2008). The male fertilizes the eggs of a female after these are laid on a leaf. He then remains by the fertilized eggs until they hatch into tadpoles, after which he carries each tadpole on his back to its own small pool of water in vegetation high in a tree. His partner remains nearby so that when he calls to her, she comes to lay an unfertilized, edible egg in each pool for her tadpole to eat. What kind of mating system is exhibited by this species?
Chapter 11 Questions:
1.McCracken found that although female Mexican free-tailed bats (Tadarida brasiliensis) usually feed their own pups, they do make occasional “mistakes,” which they could avoid if each pup were left in a spot by itself instead of in a crèche with hundreds of other babies (McCracken 1984). Does this mean that the parental behavior of this species is not adaptive? Use a cost–benefit approach to develop alternative hypotheses to account for these “mistakes.”
2. In some cases, males or females do care for young of their own species that are not their own, as when certain male fish take over and protect egg masses being brooded by other males or when female ducks acquire ducklings that have just left someone else’s nest. Propose alternative hypotheses to explain this phenomenon. Under what circumstances might adoptions actually raise the caregiver’s reproductive success? Under what other circumstances might adopters help nongenetic offspring as a cost of achieving some other goal?