Territorial Conflicts over Prey: Domination by Large Male Salamanders

Abstract

Evolutionary game theory suggests that the winners of intraspecific contests should possess a favorable asymmetry in either fighting ability (e.g., body size) or in prior ownership of the disputed resource, such as residency in a territory (Maynard Smith and Price, 1973; Maynard Smith and Parker, 1976; Hammerstein, 1981). The effect of body size on an individual's competitive ability has been studied in a variety of invertebrates (Crespi, 1986; Glass and Huntingford, 1988; Polak, 1994) and vertebrates (Clutton-Brock and Albon, 1979; Dugatkin and Biederman, 1991; Stamps and Krishnan, 1994). Except in a few cases (e.g., Zamudio et al., 1995), large size generally confers an advantage in pairwise contests for limited resources, such as food and mates (Austad, 1983; Otronen, 1984; Verrell, 1986). In the territorial salamander Plethodon cinereus, residents of territories possess significantly larger body sizes than individuals that do not possess territories (the socalled floaters; Mathis, 1990). On the basis of this observation, Mathis (1990) proposed the hypothesis that larger individuals gain and maintain possession of territories through superior aggression. However, her hypothesis may also be explained by the alternative that residents of territories generally have more access to prey than do floaters and thus grow at increased rates and attain relatively larger body sizes.