On the reproductive energetics of chorusing males: Energy depletion profiles, restoration and growth in two sympatric species of Ranidella (Anura)

The reproductive activity of males of two species of Ranidella was recorded for four years. Linear densities and vocal activity were monitored, and correlated with rainfall. Energy and ash content of somatic tissue were examined during the course of breeding seasons. Depletions of energy reserves in somatic tissue, fat-bodies and livers were charted through each breeding season. Allometric equations linking these energetic quantities with snout-vent length were used to estimate the growth between breeding seasons of soma, fat-bodies and livers. Males invest heavily in current reproduction and relatively little in growth. Virtually all of a male's reproductive expenditure is directed to mechanisms of intrasexual competition for matings rather than investment in gonads, gametes or parental behavior.