Phonotactic responses and selectivity of barking treefrogs (Hyla gratiosa) to chorus sounds
- 69 Downloads
We tested the long-standing hypothesis that female frogs are attracted to the sound of a chorus of conspecific males from a distance. We studied the barking treefrog (Hyla gratiosa) because the location of choruses is unpredictable; thus, chorus sound indicates the presence of conspecific males as well as the location of a suitable breeding site.
We measured the sound pressure level (SPL in dB re 20 μPa) in the 500 Hz octave band at various distances from choruses. The primary spectral peak in the advertisement call of this species is 400–500 Hz.
The pattern of chorus sound attenuation in the 500 Hz band at two different sites was very similar and generally followed the pattern expected from geometrical spreading from a point source (Fig. 3). At one of the sites the SPL measured near ground level was always higher than that at a point 1 m above the ground (Fig. 3).
Spectral analyses of the chorus sound at different distances showed that the low-frequency spectral peak in the range of 400–500 Hz was a prominent component, especially at 80–160 m (Figs. 1, 4). Amplitude peaks that corresponded to individual calls ofH. gratiosa and other species were also evident in oscillograms of recordings made at 160 m (Fig. 1).
Gravid females oriented and moved toward a source of conspecific chorus sounds (originally recorded at 160 m from the pond) played back at 38–40 dB SPL in the 500 Hz octave band (Fig. 1, Table 1). Background noise levels were 43–47 dB SPL (C-weighted) and 24–25 dB SPL in the 500 Hz octave band.
In a two-stimulus, choice experiment, females ofH. gratiosa always chose the source of a mixed chorus (H. gratiosa andH. cinerea) sound with conspecific males to a source of a pure chorus sound ofH. cinerea (Fig. 2, Table 2).
KeywordsBark Sound Pressure Sound Pressure Level Spectral Peak Gravid Female
Unable to display preview. Download preview PDF.
- Broch JT (1971) The application of Brüel and Kjaer measuring systems to acoustic noise measurements, 2nd edn. K Larsen & Son, Sobog, DenmarkGoogle Scholar
- Capranica RR, Moffat AJM (1983) Neurobehavioral correlates of sound communication in anurans. In: Ewert JP, Capranica RR, Ingle DJ (eds) Advances in vertebrate neuroethology. Plenum Press, New YorkGoogle Scholar
- Ehret G, Gerhardt HC (1980) Auditory masking and effects of noise on responses of the green treefrog (Hyla cinerea) to synthetic mating calls. J Comp Physiol 141:13–18Google Scholar
- Embleton TFW, Piercy JE, Olson N (1976) Outdoor sound propagation over ground of finite impedance. J Acoust Soc Am 59:267–277Google Scholar
- Ferguson DE, Landreth HF (1966) Celestial orientation of Fowler's toad,Bufo fowerli. Behaviour 26:105–123Google Scholar
- Gerhardt HC (1981) Mating call recognition in the barking treefrog (Hyla gratiosa): responses to synthetic calls and comparisons with the green treefrog (Hyla cinerea). J Comp Physiol 144:17–25Google Scholar
- Griffin DR, Hopkins CD (1974) Sounds audible to migrating birds. Anim Behav 22:672–678Google Scholar
- Heusser H (1958) Über die Beziehungen der Erdkröte (Bufo bufo L) zu ihrem Laichplatz. I. Behaviour 12:93–109Google Scholar
- Landreth HF, Christensen MT (1971) Orientation of the plains spadefoot toad,Scaphiopus bombifrons, to solar cues. Herpetologica 27:454–461Google Scholar
- Landreth HF, Ferguson DE (1966) Evidence of sun-compass orientation in the chorus frog,Pseudacris triseriata. Herpetologica 22:106–112Google Scholar
- Moss CF, Simmons AM (1986) Frequency selectivity of hearing in the green treefrog,Hyla cinerea. J Comp Physiol A 159:257–266Google Scholar
- Oldham RS (1966) Spring movements in the American toad,Bufo americanus. Can J Zool 44:63–100Google Scholar
- Oldham RS (1967) Orienting mechanisms of the green frog,Rana clamitans. Ecology 48:477–491Google Scholar
- Oldham RS, Gerhardt HC (1975) Behavioral isolation of the treefrogsHyla cinerea andHyla gratiosa. Copeia 1975:223–231Google Scholar
- Perrill SA, Daniel RE (1983) Multiple egg clutches inHyla regilla, H. cinerea, andH. gratiosa. Copeia 1983:513–516Google Scholar
- Rheinlaender J, Gerhardt HC, Yager D, Capranica RR (1979) Accuracy of phonotaxis in the green treefrog (Hyla cinerea). J Comp Physiol 133:247–255Google Scholar
- Salthe SN, Mecham JS (1974) Reproductive and courtship patterns. In: Lofts B (ed) Physiology of the Amphibia, vol 3. Academic Press, New York, pp 309–521Google Scholar
- Savage RM (1961) The ecology and life history of the common frog. Pitman & Sons, LondonGoogle Scholar
- Wells KD (1977) The social behaviour of anuran amphibians. Anim Behav 25:666–693Google Scholar
- Wiley RH, Richards DG (1978) Physical constraints on acoustic communication in the atmosphere: implications for the evolution of animal vocalizations. Behav Ecol Sociobiol 3:69–94Google Scholar