The breeding biologies of three species of treefrogs with hyperextended vocal repertoires (Gracixalus; Anura: Rhacophoridae)

Abstract

Gracixalus gracilipes, G. quangi, and G. supercornutus are small, morphologically and molecularly similar treefrogs with green blood from Vietnam, Laos and southern China. The breeding biologies, eggs, embryos and larvae of these three species are poorly known, and the male advertisement call of only G. quangi is known; this species has a hyperextended vocal repertoire. We provide new information on the breeding habitats, eggs, embryos and tadpoles of these three species and describe the calls of G. gracilipes and G. supercornutus. All three species deposit egg clumps on leaves overhanging shallow pools and puddles in forests. Like G. quangi, the calls of G. gracilipes and G. supercornutus are non-stereotypical, with individual calls highly variable in structure, duration, amplitude and frequency. Both calls are frequency modulated and have a dominant frequency of 4.1-4.7 kHz and many harmonics. The functional significance of these variations is unknown, and it is not known how common hyperextended call repertoires are within the genus.