High Diversity of Brood Parasites in China and Coevolution Between Cuckoos and Their Hosts

Abstract

Ecosystems consisting of multiple cuckoo species and their hosts constitute interesting examples of complex coevolutionary interactions. Competition among cuckoo species may increase the intensity of selection for adaptation to specialization but also for specific host species to evolve particular defenses against a specific species of cuckoo. Such specialization is further exacerbated by the evolution of different color morphs of the plumage of cuckoos but also by the evolution of different color morphs of cuckoo eggs. Here we review host use by sympatric brood parasitic cuckoos and coevolution in such communities of cuckoos and hosts in China. There was intense competition and overlap in host use among cuckoo species in China, and competitive exclusion may play an important role in the evolution of these patterns. In addition, parasitic cuckoos of median body size showed a particularly strong flexibility in exploiting hosts differing in body sizes because cuckoos of intermediate body size are particularly widespread. We hypothesize that such sympatric assemblages of multiple species of cuckoo may serve as model systems for the study of frequency-dependent selection and its evolutionary consequences.