Natural growth rates of Ambystoma maculatum in Alabama

The Spotted Salamander (Ambystoma maculatum) is widespread throughout the eastern United States and southern Canada. In 1997, we initiated a long-term study of A. maculatum at a breeding pond in Calhoun County, Alabama. Each winter, we captured salamanders as they returned to breed and inserted passive integrated transponders to permit positive identification of recaptures. We fit the von Bertalanffy growth-interval equation to data on snout-vent length taken from individuals captured and recaptured in different years and estimated intrinsic growth rates for both males and females. Males displayed rapid juvenile growth, which slowed as they neared estimated maximum size. Females, however, displayed relatively constant growth until nearing their estimated maximum size. The intrinsic growth rate of females was lower than that estimated for males. We hypothesize that sex-specific growth patterns maximize reproductive efforts of A. maculatum.