Breeding behaviour and reproduction in the Pampa de Achala toad, Bufo achalensis

Abstract

AbstractDuring 1999 and 2000 the reproductive behaviour, breeding site characteristics and reproduction of Bufo achalensis were studied mainly at La Ciénaga stream, Pampa de Achala, Argentina, using capture-recapture and skeletochronology methods. Breeding activity occurred from mid-August to mid-September and was explosive. Males and females congregated at night at selected, but scarce, breeding sites, resulting in a patchy distribution of small breeding populations near to the stream source. The sex ratio (♂ : ♀) of the breeding population ranged between 0.65 : 1 and 1.16 : 1. On average, breeding males were larger and older than breeding females. Although most females and males reached sexual maturity at four and five years of age, some bred for the first time at the ages of three and four years respectively. Neither size dependent nor size assortative pairings were found. Male reproductive success was not related to body size (SVL) but was related to the number of nights spent at a breeding site. Females laid between 700-2,390 eggs. Eggs hatched approximately nine days after deposition and larval development was completed in about two months.