Sexual Differences in the Behavioral Response of Túngara Frogs, Physalaemus pustulosus, to Cues Associated with Increased Predation Risk

In most species, engaging in mating behaviors entails high risks for both males and females. Advertizing has long been recognized as a hazardous activity since Darwin acknowledged the dangers males undertake when displaying to attract females (Darwin 1859). Searching for a mate, however, has only recently been considered a risky behavior (reviewed in Lima & Dill 1990). Females navigating breeding areas in search of a mate are vulnerable to opportunistic predators attracted by signaling males and may be even more susceptible to predation than males themselves (Hedrick & Dill 1993; Pocklington & Dill 1995; Godin & Briggs 1996; Gong & Gibson 1996; Dill et al. 1999). In the case of decorated crickets, for instance, Mediterranean house geckos localize burrows of calling males but cannot reach the cricket inside. Thus, they wait for approaching females also attracted to the calls of the male (Sakaluk & Belwood 1984). In situations like this, selection may act on females to reduce predation-related costs. There is increasing empirical evidence that susceptibility to predation affects female mating behavior in invertebrates, fish, birds and mammals (Gibson & Bachman 1992; Wilson et al. 1994; Gong & Gibson 1996; Johnson & Basolo 2003; Su & Li 2006). While dangers to males have been investigated, and recent Correspondence Ximena E. Bernal, Section of Integrative Biology C0930, University of Texas, Austin, TX 78712, USA. E-mail: [email protected]