Female courtship calls of the litter frog (Rana curtipes) in the tropical forests of Western Ghats, South India

Abstract

AbstractWe noticed an uncommon phenomenon of female vocalization in the forest litter frog, Rana curtipes during the breeding season. We digitally recorded the male and female vocalization of the litter frogs in the tropical rain forests of the Western Ghats of South India and analyzed the call characteristics. The female call varied from the male call by being single note in composition. In contrast, the male calls were composed of seven to eight notes and longer in duration. We observed that gravid females, occupying the same location every day, emitted low volume calls when numerous males were found calling at that time. Some females arrived asynchronously and called even in the absence of males possibly to declare their receptive condition. Calling females responded agonistically to receptive conspecifics of the same sex. In addition to declaring receptivity, this calling behavior may be a response to adjacent competing females when the males are few.