Moser, C. F. & R. Lingnau

Vocalization of the Sullen toad, Scythrophrys sawayae (Anura: Leptodactylidae: Paratelmatobiinae), from near its type locality, Paraná, Brazil. pp. 167-170 plus Supplementary document

Abstract. Scythrophrys sawayae is a small leaf litter frog that vocalizes at night, usually under leaf litter, in choruses of 10 to more than 30 individuals. The advertisement call of this species consists of a single note with pulses, with an average duration of 0.24 s, a pulse duration of 0.007 s, and an inter-pulse interval of 0.04 s. Advertisement calls have a high call rate and a high pitch, with a dominant frequency around 4000 Hz and a maximum frequency of 5500 Hz. Aggressive calls consist of a multipulsed note with frequencies that are similar to the advertisement call.