Call intensity and female preferences in the European green toad

Citation
S. Castellano et al., Call intensity and female preferences in the European green toad, ETHOLOGY, 106(12), 2000, pp. 1129-1141
Citations number
34
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Animal Sciences","Neurosciences & Behavoir
Journal title
ETHOLOGY
ISSN journal
0179-1613 → ACNP
Volume
106
Issue
12
Year of publication
2000
Pages
1129 - 1141
Database
ISI
SICI code
0179-1613(200012)106:12<1129:CIAFPI>2.0.ZU;2-K
Abstract
In the present paper we study the pattern of variation in call intensity in a natural population of the European green toad (Bufo viridis), and we ana lyse females preferences for this property by means of playback experiments . Although call sound pressure level (SPL) shows little within-bout variati on, we found significant positive correlation between call SPL and fundamen tal frequency: on average, an increase of 6 dB SPL produces a 100-Hz increa se in fundamental frequency. When females were given a choice between two c alls differing by 10 and 6 dB SPL, they significantly preferred the loudest call, whereas they did not discriminate between calls differing by 3 dB. T o test whether a 3-dB difference reflects a sensory or behavioural limit, w e carried out three experiments where females were given a choice between t wo calls differing in both duration (4 s and 6 s, respectively) and SPL (3 dB). In all three experiments, the longer call attracted a larger number of females, but the 3-dB difference did not show any significant effect. Fina lly, we investigated the relationships between call intensity and frequency on female preferences. Previous experiments showed size-dependent preferen ces for calls with lower-than-average frequencies (1.3 kHz) over calls with higher-than-average frequencies (1.6 kHz). Here, we show that this weak pr eference is abruptly reversed when the highest-pitched call is broadcast at an intensity 6 dB higher than the alternative.