ABSTRACT
Rana tigrina and Tomopterna breviceps occur as sympatric species at Dharwad, India. Sexually mature males produce advertisement calls. The advertisement call of both the species consist of a number of calls produced in series forming a call group· Each call group of Rana tigrina comprises 10-40 calls, whereas that of Tomopterna breviceps consists 13-141 calls. Each call consists of a pulse group with variable number of pulses which lack pulse interval. Calls of both the species exhibit similarities in (i) call consisting of series of calls with a pulse group in each call, (ii) absence of pulse interval within the pulse group, (iii) the amplitude of the first pulse being always small, and (iv) the frequency spectrum beginning from 200 Hz. Based on the similarities in the spectral features of the calls, it is suggested that the two species may be closely related to each other.
ABSTRACT
The period of calling activity of Polypedates maculatus lies between April and October. Males possess an indistinct subgular vocal sac which turns yellow during the breeding season. Mating calls type I, type II and distress calls have been identified. Mating calls type I and type II consist of a single pulse group. Type I call comprises of 7-22 pulses, whereas type II call consists of 4-6 pulses. Pulses are short. The frequency spectrum is broad and continuous. Distress calls, with 6 hormonics, are given by the females with their mouth open.