We examined the energetics of calling by male Crinia georgiana because other studies have shown that the costs of attracting a mate for male frogs can limit chorus participation, which in turn can explain significant variation in male mating success. The metabolic cost of producing a single note for C georgiana (0.0006 +/- 0.0001 ml O-2 g(-1) min movement(-1) note(-1)) was similar to the cost for other species, but males called at a comparatively low rate (mean = 136.0 +/- 21.5 calls per hour). The production of multiple-note calls by C georgiana is not an energy-saving mechanism because it is not more expensive to produce the same number of notes with single-note calls. Most males were found at the breeding site on one or two nights only during the breeding season, and peak calling activity occurred for approximately nine hours per day. Further, there were only two nights of peak chorus activity during the breeding season (82 days). These data suggest that the overall reproductive effort of male C georgiana is low. We also show that female mate choice preferences for call rate might allow males to call at a low rate. We discuss the possibility that a positive relationship between male mating success and chorus attendance may not hold for all males in a species because the costs and benefits of attending the chorus can vary considerably among individuals.
|Publication status||Published - 2003|