Begging Call Mimicry by Brood Parasite Nestlings: Adaptation, Manipulation and Development

Begging calls provide nestling brood parasites with a powerful and flexible tool for avoiding rejection, altering parental provisioning and competing with host nestmates. Despite much research into the topic, no synthesis of parasite vocal strategies for host manipulation has yet been made. In this chapter, we begin by reviewing the literature on reported similarity between the begging calls of avian brood parasites and their hosts. We show that such similarity is a more widespread phenomenon than previously appreciated. Secondly, we examine the selection pressures that drive the evolution of begging call mimicry by avian brood parasites, assess their importance and illustrate them with empirical examples. Finally, we propose a theoretical framework to explain variation in the ways that brood parasite begging calls develop. We suggest that the mode of development can be predicted from a consideration of the accuracy of genetic cues (as mediated by parasite specialisation levels) and the benefits to the young parasite of using environmental cues to modulate their begging call (as influenced by levels of discrimination shown by host parents). Perhaps the main contribution of this chapter is to highlight how little we know about brood parasitic begging calls. This points the way for future work on this topic.