Relationship of Pond Drying to the Reproductive Success of the Salamander Ambystoma talpoideum

Abstract

The relationship of pond drying, female population size, and total egg production to the reproductive success (number of metamorphosing juveniles) of the salamRnder Ambystoma talpoideum was studied in natural and experimental populations. Breeding population size was correlated with rainfall during the migratory season but not with the production of juveniles in the previous year. Reproductive success and survival to metamorphosis were correlated with the number of days in a year that a pond had standing water but not with the number of breeding females or total number of eggs oviposited. The time of metamorphosis was correlated with the date that the pond dried. However, metamorphosing later in the season did not result in larger body size at metamorphosis, only more mptamorphs. Catastrophic mortality occurred when breeding ponds dried early, resulting from the failure of larvae to reach a threshold size or developmental stage to initiate metamorphosis. Manipulation of an experimental pond suggested that growth rate of larvae decreased as the pond dried. Desiccation was identified as a factor influencing the fluctuations in reproductive success of a species breeding in temporary ponds. .