NOVEL OBSERVATIONS ON Leptodactylus fuscus (ANURA: LEPTODACTYLIDAE) MATING BEHAVIOR: A COUPLE IN ACOUSTIC INTERACTION

In most anuran species, males are vocally active and females are selective, approaching to the selected males in silence. However, in some species females may call at low intensities. As observations on reproductive behavior are still incipient for several species, recordings of female calls are rare. Here, we describe for the first time an acoustic interaction between a pair of Leptodactylus fuscus, including a first observation with the male capping the nest openings with mud. We extracted the male and female calls from the video made during the opportunistic observation occurred at the municipality of Santana, State of Amapá, Brazil. We converted the video extension (mp4) to a readable sound file (wav) with 44.1 kHz and 24 bits of resolution. We analyzed 50 calls (31 emitted by the male and 19 emitted by the female) in the software Raven pro 1.4. Male calls were composed by a single note formed by one large pulse. The note present an ascendant frequency modulation. Female calls are equally composed by a single note, however formed by two pulses. The first pulse perform an ascendant frequency modulation phase, while the second perform an accentuated descendent frequency modulation at the call ending. Male calls are longer and occupy a higher band frequency than the female calls. Except by the minimum frequency, all female call properties showed higher variation than the male call properties. Such high variability on female calls may be due to its function, once female calls are a receptivity signal used in close-range interactions and not necessarily have a species recognition function. However, a general variation pattern for calls of both sexes agree with the literature regarding that they present spectral properties showing less variation than temporal properties. Our work contributes to the general knowledge about leptodactilids reproductive behavior and acoustic interaction.