Natural history notes of Rhinella proboscidea (Anura, Bufonidae) from a non-flooded forest in central Amazon

Abstract

Rhinella proboscidea , a toad of the Rhinella margaritifera species group, is found in terra firme (non-flooded) forests in central Amazon. This species reproduces in streamside ponds and uses small seedling plants to rest during the night. In this study, we present data on the variation in abundance, size and weight of adults and juveniles, on the relationship between body mass and size, and we characterize the resting sites and some aspects of R. proboscidea reproductive events throughout two rainy seasons. We captured 359 individuals (55 males, 81 females, 204 juveniles and19 undetermined). Highest abundance of females and juveniles was found in the fifth sampling period. We did not detected sexual dimorphism in body size and mass between males and females. Body size of males, females and juveniles varied between rainy seasons. There was a positive relationship between body size and mass considering all individuals or sexes. Reproductive events were observed from the middle to the end of the rainy season on few occasions. In conclusion, R. proboscidea is an explosive breeder, and juvenile recruitment events occurred in the end of the rainy season, probably related to the variation in water body availability for reproduction. Moreover, the absence of sexual dimorphism in body size and mass for this species disagrees with what is known for other species in the R. margaritifera group.