Association between Breeding Cycle and Male Body Condition in Hyla labialis

Abstract

During four consecutive years, I used a mark-recapture method to study the relationship between breeding cycle and changes in male body condition in an Andean population of Hyla labialis. The annual weather pattern consisted of a long unimodal rainy season from February to November and a short dry season in December and January. A pronounced unimodal annual pattern in body condition was positively correlated with the amount of local rainfall. The annual reproductive cycle began during the rainy season in August or September, when males had high body energy reserves. Breeding activity ended in April or May of the following year, when males were in poor body condition. Reproductive activity was divided into two breeding periods by a short reproductive recess during the dry season. The annual cycle ended with a recovery period during the wettest months, when males regained their body condition while breeding activity ceased. Abundance of males and mated pairs was bimodal, with a high peak in October during the first breeding period and a lower peak in February during the second breeding period. Abundance was low during the driest and wettest months of the year. Individually marked males participated in up to seven consecutive breeding periods. Males found repeatedly in the same breeding period had the lowest body condition. A male's body condition declined as his time at the breeding aggregation increased and improved during recovery periods. Although rainfall pattern seemed to influence the amount of breeding activity, body condition seemed to determine the onset and end of the annual breeding cycle.