title: Temperature dependence of auditory thresholds in two Central European anurans, Bombina variegata variegata (L.) and Rana ridibunda ridibunda Pall. (Amphibia), and its relation to calling.
abstract: We recorded multi-unit activity from the torus semicircularis in two European anurans, to test for temperature dependence of the auditory thresholds. In Rana r. ridibunda the entire threshold-vs.-frequency curve shifts downward for a temperature increase from 5° to 15° C; the average increase in sensitivity is 14 dB. In Bombina v. variegata the increase in sensitivity averages 8 dB for a rise in temperature from 12° to 20° C; in addition, the best frequency is shifted by about 150 Hz by this increase in temperature, from 350-400 Hz to 550 Hz. The audiogram of Rana r. ridibunda differs from that of Bombina v. variegata in that it is markedly trimodal; the sensitivity maxima for Rana fall at 300-500 Hz, 750-1000 Hz and 1250-1700 Hz.
authors.affiliation: Zoologisches Institut der Universität Bonn, D-5300 Bonn, Federal Republic of Germany.
authors.forename: L
authors.initials: L
authors.lastname: Hubl
authors.forename: R
authors.initials: R
authors.lastname: Mohneke
authors.forename: H
authors.initials: H
authors.lastname: Schneider