Potential competitive interactions between larvae of Pseudophryne bibroni and P. semimarmorata (Anura : Leptodactylidae)

Abstract

The two frog species Pseudophryne bibroni and P. semimarmorata are known to have allopatric distributions which meet in narrow hybrid zones in south-eastern Australia. A preliminary test is described of the hypothesis that interspecific competition plays a part in maintaining the narrow zones. Tadpoles from allopatric populations of each species were raised in single-species and mixed-species groups in experimental enclosures in a pool in the range of P. bibroni. Competitive superiority of P. bibroni was shown both in survival to metamorphosis and in size achieved at this stage. It is suggested that competition may be an important ecological component of the interactions taking place between the two taxa where their distributions meet.