「首发」沃邦名师3月10日亚太SAT考试考情速递(10)

The same unpredictable environments thatfavor cooperation could also favor alternative breeding strategies such asparasitism. However, the authors go on to show that even within geographicalregions rich in both parasites and cooperators—Australia and southern Africa—cooperativebreeders are much more likely than noncooperative species to be targeted bybrood parasites. To determine the reasons for this correlation, Feeney et al.studied cooperative breeding in superb fairy-wrens (Malurus cyaneus) inAustralia. Horsfield’s bronze-cuckoos (Chalcites basalis) should bene? t fromtargeting larger groups of fairy-wrens because more helpers mean faster chickgrowth. Yet, data from a 6-year field study show that in practice, cuckoosrarely experience this advantage, because larger groups of fairywrens much moreeffectively detect and repel egg-laying intrusions by cuckoo females,mobilizing group defenses with a cuckoospeci? c alarm call. Thus, cooperationand parasitism could reciprocally in? uence one another: Cooperators might bemore attractive targets because they make better foster parents, but once