Population ecology of the Australian frog Crinia signifera: larvae

Abstract

There are few published studies of the population ecology of the larvae of Australian native anurans. In this study we report on the population dynamics of the larvae of the Australian frog Crinia signifera at a study site near Bridgewater in the Adelaide Hills, South Australia. The predator community was also monitored to provide an indication of the importance of predation in influencing the population dynamics of C. signifera larvae. Pool drying meant larvae failed to metamorphose from temporary pools in all years of the study. In a permanent pond, mortality was high and variable, with an average of 10% survival over the three years of the study. There was a complete failure to recruit to the terrestrial phase in one year. Predation pressure was thought to be the most important source of mortality in the permanent pond, although predator numbers varied considerably between and within years. When combined with information on the population ecology of the embryonic (Williamson and Bull 1994) and terrestrial (Williamson and Bull 1996) stages, the data suggest that the aquatic phase is the key phase in the population dynamics of this species.