VOCAL REPERTORY OF TWO SPECIES OF THE LEPTODACTYLUS PENTADACTYLUS GROUP (ANURA, LEPTODACTYLIDAE)

Abstract

Among frogs, vocalizations play important roles in their social interactions. Herein we describe
fi ve new types of vocalizations for two foam-nesting species of the Leptodactylus pentadactylus
group, L. syphax and L. labyrinthicus. Behavioral observations and recordings were done in four
localities within the Cerrado biome, at southeast and central Brazil. Before emitting advertisement
calls, males of L. syphax often started producing a sequence of notes, which gradually turned into the
advertisement call. These different notes may be an introductory call, which would serve to prepare
the vocal structures for the emission of the high-frequency/amplitude advertisement calls. A male of
L. syphax was emitting advertisement calls when a female approached and started to emit brief and
low-amplitude calls; these vocalizations probably are reciprocation calls. Males of L. labyrinthicus
involved in agonistic interactions can emit vocal cracks (encounter call) and deep rough sounds (territorial
calls). Five courting males of L. labyrinthicus released screams with their mouth slightly opened
in response to the approach of human observers. We conclude that these screams do not represent
distress or territorial calls.