© 1994 International Society for Behavioral Ecology
research-article |
Net costs of group living in a solitary forager, the Eurasian badger (Meles meles)
Wildlife Conservation Research Unit, Department of Zoology South Parks Road, Oxford, OXI 3PS UK
ABSTRACT
Group living is expected to evolve under two extreme conditions: when there are net benefits to the individual of living in a group and when there are net costs to living in a group together with strong ecological constraints on dispersal and independent breeding. A third condition may facilitate group formation: when the territorial defense of resources that are dispersed widely or renewed at high rates allows groups to form at no cost to group members. Eurasian badgers are solitary over a large part of their geographic distribution and forage alone even where diey live in territorial groups. To determine which of the three conditions best explains group living in badgers, we analyzed dispersal and breeding patterns. Using these data we describe the mechanism of group formation and the net costs or benefits of group living in 16 badger groups in one population. Groups form primarily by the retention of young on their natal territory. Typically, groups contain one or more sexually mature but nonbreeding females in addition to one or more breeding females. Females do not benefit from group living as indicated by the lack of relationships, or perhaps negative relationships, between the proportion of adult females that bred in a group and mean reproductive success, on the one hand, and group size and components of group size, on the other. A high reproductive failure rate among females in this and other populations of social badgers, as compared with a population of solitary badgers, suggests that there is a cost of group living to females. We propose that if badgers defend resources whose spatial distribution or high renewal rates allow groups to form on a territory at litde or no cost to group members, weak ecological constraints on dispersal and independent breeding are sufficient to explain the formation of groups. Badgers appear to have not evolved cooperative breeding in response to these ecological conditions, perhaps because badger groups represent an early stage in the evolution of carnivore sociality.
Key words: dispersal, Eurasian badger, European badger, group breeding, group living, Meles meles, social evolution.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  A. L. Engh, S. M. Funk, R. C. V. Horn, K. T. Scribner, M. W. Bruford, S. Libants, M. Szykman, L. Smale, and K. E. Holekamp Reproductive skew among males in a female-dominated mammalian society Behav. Ecol., March 1, 2002; 13(2): 193 - 200. [Abstract] [Full Text] [PDF]
|
|