Independence of Evoked Vocal Responses from Stimulus Direction in Burrowing Frogs Eupsophus (Leptodactylidae)

Abstract

Localization of a sound source is important for animals in mating contexts: females generally orient towards signalling males, and males can estimate the position and quality of potential rivals. In anurans, the effect of sound direction on evoked vocal responses has been studied in males of Rana catesbeiana, which alter their vocal responses depending on the location of the stimulus. The current study explored the effects of sound direction in Eupsophus calcaratus, a frog that calls from inside burrows having resonance that would hinder the localization of incoming sounds. The vocal responses of 11 males to synthetic imitations of the conspecific advertisement call broadcast from loudspeakers positioned in front, to the right and left from the burrow openings were similar in terms of call rate, duration and latency. The invariance of the vocal responses indicates that for burrowing male frogs engaged in chorusing behaviour, the specific location of an opponent does not alter the persistence of vocal activity.

Contrasting Propagation of Natural Calls of Two Anuran Species from the South American Temperate Forest

“…emiliopugini call from inside small burrows along the borders of small streams or pools among vegetation composed mainly of mosses ( Rhacomytrium) , grasses, ( Scyrpus and Myrteola ) and ferns ( Blechnum ). Previous studies on the vocal behavior of both species have been carried out at this site [ 27 – 35 ].…”

Estado de conocimiento y conservación de los anfibios de Chile: una síntesis de los últimos 10 años de investigación

“…Penna & Márquez (2007) describieron cómo las vocalizaciones externas conespecífi cas se modifi can al penetrar en las cavidades ocupadas por machos de E. roseus, un fenómeno que se había observado en otras dos especies del género. Penna & Quispe (2007) mostraron que E. calcaratus no responde diferencialmente a la dirección de la emisión de cantos conespecífi cos. Una serie de estudios muestra que los patrones de propagación de los cantos en condiciones naturales y los umbrales auditivos a cantos conespecífi cos son diferentes en las especies simpátricas E. calcaratus y E. emiliopugini (Penna et al 2013, Penna & Moreno-Gómez 2014. En E. calcaratus la degradación del canto y el umbral auditivo son mayores, por lo que la comunicación en esta especie estaría restringida a distancias menores de 2 m.…”