3 results
1 - Evolutionary origins
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- By J. David Ligon, University of New Mexico, D. Brent Burt, Stephen F. Austin State University
- Edited by Walter D. Koenig, University of California, Berkeley, Janis L. Dickinson, University of California, Berkeley
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- Book:
- Ecology and Evolution of Cooperative Breeding in Birds
- Published online:
- 02 December 2009
- Print publication:
- 22 April 2004, pp 5-34
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Summary
Cooperative breeding (hereafter often abbreviated as CB) is an umbrella label that includes a diverse array of mating and social systems (Ligon 1999). For example, Brown (1987) lists 13 separate categories of CB (see also Chapter 5). The variability in the forms of CB is due to differences in both the strength and the forms of selection on helping behaviors, mating strategies, and other aspects of group living. Here we follow the commonly employed definition of avian cooperative breeding, which is that it involves the existence of social units composed of two or more breeding birds, plus one or more (often presumed) non-breeding “helpers-at-the-nest” (Brown 1987; Edwards and Naeem 1993). It is the feeding of young birds by the helpers – also referred to as alloparental behavior – that characterizes cooperative breeding and that has made it of singular interest.
For most of the history of CB studies, researchers have sought ecological factors that might have promoted the evolutionary development of CB. This search has met with limited success, in part because ecological and climatic considerations, in themselves, offer little predictive power beyond the fact that north-temperate-zone species are unlikely to be cooperative breeders (Heinsohn et al. 1990; Mumme 1992a; Cockburn 1996). Even in tropical and subtropical areas, where cooperative breeders occur most frequently, one typically cannot offer a good guess, based solely on environmental conditions, as to whether or not a given species will prove to exhibit CB.
2 - Co-operation and reciprocity in birds and mammals
- Edited by Peter G. Hepper, Queen's University Belfast
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- Book:
- Kin Recognition
- Published online:
- 06 January 2010
- Print publication:
- 28 June 1991, pp 30-59
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Summary
Co-operation can be defined as any mutually beneficial interaction between two or more individuals. By this standard definition, many, probably most, birds and mammals exhibit co-operation in one or more contexts. Cooperation can range from a simple apparently incidental group effect, such as the simultaneous mobbing of an owl by individuals of two species of songbirds, to complex mutual dependence, such as the rotating sentinel systems of some group-living animals (e.g. McGowan, 1987). Virtually all researchers recognize co-operation when they see it and its widespread occurrence is not a matter of controversy (Axelrod & Hamilton, 1981).
The phenomenon of co-operative behaviour is a fascinating one, for several reasons. First, co-operation is a universal human trait and the vast majority of interactions among individual humans are co-operative to a greater or lesser degree. Thus, it is easy for people to empathize with the cooperative behaviours they observe in animals.
Second, highly developed intra-group co-operation is often seen in species also characterized by high levels of inter-group competition. Our own species is the prime example of this relationship. Killing of conspecifics may be viewed as indicative of extreme intraspecific competition, and human warfare, the searching out and killing of male chimpanzees (Pan troglodytes) by groups of males (Goodall, 1986), the expulsion or killing of male prideholding lions, (Panthera leo) by invading coalitions of males (e.g. Packer & Pusey, 1982) and the running down and killing of a lone wolf (Canis lupis) by a pack (Mech, 1970), illustrate this relationship between co-operation and competition.
4 - Cooperative breeding strategies among birds
- Edited by Alan H. Brush, George A. Clark, Jr.
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- Book:
- Perspectives in Ornithology
- Published online:
- 04 August 2010
- Print publication:
- 31 August 1983, pp 93-134
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Summary
The cooperative rearing of young is a topic of considerable interest to both biological and social scientists. Such behavior reaches its extreme development in many eusocial insect societies, where vast numbers of individuals live their entire lives as sterile workers, rearing young but never themselves becoming reproductives (Wilson 1971). Such sterile castes have not yet been reported among vertebrates. However, there are numerous instances in which individuals of vertebrate species (most of them avian) forego breeding for a significant portion of their adult lives and spend such time helping to rear offspring that are not genetically their own.
There are three fundamental questions surrounding the topic of cooperative breeding in animals. First, what role have ecological factors played in promoting the development of such aid-giving societies? Second, how can such seemingly altruistic behavior be explained in terms of natural selection theory? Third, what behavioral tactics will members of such societies adopt to maximize their own fitness when interacting with others?
In this chapter, we will attempt to address each of these three topics. Before doing so, however, it is necessary for us to define our terms. We use “group” to describe any long-lasting association of more than two individuals (Rowley et al. 1979). An “auxiliary” is any mature, nonbreeding member of a reproducing group. It may or may not provide aid in the rearing of young. “Cooperative breeding” refers to any case where more than two birds provide care in the rearing of young.