Section 7
Chapter 6,584

Temperature and auditory thresholds bio acoustic studies of the frogs rana ridibunda ridibunda hyla arborea arborea and hyla arborea savignyi anura amphibia

Hubl, L.; Schneider, H.

Journal of Comparative Physiology A Sensory Neural and Behavioral Physiology 130(1): 17-28


Accession: 006583676

Download citation:  

The auditory thresholds of 3 frogs, 2 spp. of the genus Hyla (H. arborea arborea, H. a. savignyi) and one of the genus Rana (R. ridibunda ridibunda), were measured at 5.degree., 12.degree., 20.degree. and 28.degree. C, by recording multi-unit activity from the torus semicircularis. In the tree frogs, the upper limit of the audible range is 7000 Hz. At 5.degree. C the best frequency is 3000 Hz; the threshold (expressed in dB SPL [sound pressure level] in all cases) at this frequency is 49 dB (males) and 43 dB (females) for H. a. arborea and 42 dB (males) and 48 dB (females) for H. a. savignyi. At 12.degree. C the thresholds are lower, and they are lower still at 20.degree., reaching a minimum, at 3000 Hz, of 42 dB (males) and 38 dB (females) for H. a. arborea and 41 dB (males) and 40 dB (females) for H. a. savignyi. At frequencies of 1000 Hz and lower, thresholds are high at 5.degree. C; in part of this they are considerably lowered at 20.degree. C; at 28.degree. C there is a reduction in sensitivity to most frequencies in H. a. arborea, amounting to more than 10 dB in the males. H. a. savignyi differs in this regard; at 28.degree. sensitivity is no less than at lower temperatures, and in fact is greater in the range 1000-1400 Hz. The audible range of R. r. ridibunda is more restricted than that of the tree frogs, but it is more sensitive within this range. The highest frequency is 4500 Hz. At 5.degree. C the thresholds of the males are lowest at 500-600 Hz (42 dB) and 1400-1900 Hz (approximately 39 dB). The best frequencies of the females are 700 Hz (38 dB) and 1400 Hz (36 dB). At 12.degree. C the thresholds at 300 Hz and 1000 Hz are markedly lowered, by 10-18 dB. The thresholds of the females at 20.degree. C are still lower over almost the entire audible range; in the males only part of the range is affected. This difference persists at 28.degree. C, the threshold curve of the males being slightly raised, while that of the females is unchanged. Latencies are dependent upon temperature and sound pressure. With a rise in temperature from 5.degree.-20.degree. C the latency falls by approximately 8 ms. An increase in sound pressure from 5-30 dB SPL shortens the latency by approximately 10 ms. These changes were found in all the frogs studied.

PDF emailed within 1 workday: $29.90