Short Answer 1 (10 pts. total) Bird species such as pelicans…
Short Answer 1 (10 pts. total) Bird species such as pelicans, black eagles, and cattle egrets practice siblicide, in which an older, larger chick will attack, and often eventually kill, its younger sibling. A question central to the understanding of siblicide is why parents lay extra eggs in the first place, if these ‘marginal’ chicks are unlikely to survive. a. Describe one adaptive benefit that parents can gain from producing additional chicks, if the species is obligately siblicidal. (3 pts.) b. Mock et al. (1990) conducted an experiment in which size disparities between junior and senior cattle egret chicks were manipulated by switching eggs across nests. Briefly describe the experimental results from the Figure, below, comparing the ‘synchronous’ and the ‘normal’ conditions, and how they make sense in light of the ‘rules’ for the escalation of contests. (7 pts.). PLEASE LABEL YOUR ANSWERS WITH (a) and (b).