Population biology of the frog Leptodactylus pentadactylus in a central Amazonian rainforest

Abstract

At Manaus, Amazonas, Brazil, reproduction occurred only in September and October. Population demography was therefore characterized by the presence of discrete annual generations and a sudden increase in population density following the reproductive season. Individuals were nearly two years old at first reproduction. Survival rate was unrelated to age and relatively constant throughout the year. Food availability was highest in the late dry season and in the wet season. Mean volume of stomach contents was used to index rates of food consumption, which generally varied in concert with food availability. Size-independent, individual growth rates also varied throughout the year and were significantly correlated with rainfall, food consumption, and food availability. Seasonality in reproductive behaviour may allow recently metamorphosed juveniles to profit from predictable peaks in food availability. Prey availability, through its effect on food consumption and hence individual growth rates may influence the time that individuals take to reach sexual maturity. -from Author