On Alternative Reproductive Tactics in Anurans: Dynamic Games with Density and Frequency Dependence

Abstract

Intense mating competition and mate choice has favored the evolution of alternative mating tactics in many species. We developed a stochastic dynamic game to evaluate the choice among three alternative mating tactics by male anurans: call, satellite, or leave the chorus to forage or hide. The strategies were assumed to differ in mating success (call > satellite forage = hide), predation risk (call > satellite > forage > hide), and energetic expense (call > satellite = hide > forage). Six major predictions were derived. First, in relatively stable environments, males should enter a chorus in a synchronous pulsed pattern, with first-year males primarily choosing to be satellites on older calling males. The pulsed pattern is caused by the relatively high energetic cost of calling and the dependence of female arrival rates on chorus size (which promotes synchronization). In unstable environments, energetic constraints are reduced because favorable conditions are rare, so most males should call on favorable ni...