Anti-brood parasite defences : the role of individual and social learning

In this chapter, we consider the ways in which learning is involved in the antibrood parasitism defences that hosts deploy across the nesting cycle. Brood parasitism varies in space and through time, and hosts have accordingly evolved plastic defences that can be tuned to local conditions. Hosts can achieve their defence plasticity by individual and social learning, as well as by experienceindependent mechanisms. While these mechanisms can profoundly affect the coevolutionary dynamics between hosts and their brood parasites, our understanding of how they feature across the host nesting cycle is far from complete. Hosts can actively defend themselves against brood parasitism via a variety of behaviours, including nest defence, egg discrimination and chick discrimination. Such anti-brood parasite defences rely on the host ’ s ability to recognise and then defend against the parasitic threat, and there is good evidence that both these components of discrimination can be in fl uenced by learning. To date, most research has focused on the function of learning in nest defence, but the learning mechanisms underlying egg discrimination are much better understood; and despite some notable exceptions, the role of learning in chick discrimination remains largely unexplored. An important challenge now is to understand the observed plasticity of anti-brood parasite defences in the context of environmental heterogeneity and speci fi cally in terms of variation in the presence, detection and reliability of parasitism cues

Anti-brood Parasite Defences: The Role of Individual and Social Learning

In this chapter, we consider the ways in which learning is involved in the antibrood parasitism defences that hosts deploy across the nesting cycle. Brood parasitism varies in space and through time, and hosts have accordingly evolved plastic defences that can be tuned to local conditions. Hosts can achieve their defence plasticity by individual and social learning, as well as by experienceindependent mechanisms. While these mechanisms can profoundly affect the coevolutionary dynamics between hosts and their brood parasites, our understanding of how they feature across the host nesting cycle is far from complete. Hosts can actively defend themselves against brood parasitism via a variety of behaviours, including nest defence, egg discrimination and chick discrimination. Such anti-brood parasite defences rely on the host’s ability to recognise and then defend against the parasitic threat, and there is good evidence that both these components of discrimination can be influenced by learning. To date, most research has focused on the function of learning in nest defence, but the learning mechanisms underlying egg discrimination are much better understood; and despite some notable exceptions, the role of learning in chick discrimination remains largely unexplored. An important challenge now is to understand the observed plasticity of anti-brood parasite defences in the context of environmental heterogeneity and specifically in terms of variation in the presence, detection and reliability of parasitism cues

Parasitic Behaviour of Interspecific Brood Parasitic Females

Interspecific avian brood parasites have to solve unique problems associated with their reproductive habit: they need to recognize potential hosts, search for and locate their nests, monitor nests progress and return to them at the appropriate time for egg-laying. In addition, parasitic females may improve the survival of their own eggs and chicks by removing or destroying part of the clutch content. Lastly, they should avoid egg-laying in nests parasitized by other females and remember the nests in which they have laid eggs to avoid laying two or more eggs in the same host nest to prevent harming their own previously laid eggs and generating competition between their own offspring. In this chapter we summarize information on the behaviour of parasitic females from the moment they start searching for host nests until they parasitize them (Fig. 1). We review the different hypotheses for explaining the recognition of hosts and the cues used to search for and locate their nests. We also review the different adaptive explanations for the removal or destruction of eggs as well as the information on competition among females for host nests and repeat parasitism.Fil: Reboreda, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; ArgentinaFil: Fiorini, Vanina Dafne. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; ArgentinaFil: Cecilia de Mársico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; ArgentinaFil: Gloag, Ros. University of Sydney; AustraliaFil: Scardamaglia, Romina Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentin