Proceedings of the Royal Society B: Biological Sciences, Volume 274,
Number 1609 / February 22, 2007
Clémentine Vignal, Darcy Kelley
Significance of temporal and spectral acoustic cues for sexual
recognition in Xenopus laevis
<http://www.journals.royalsoc.ac.uk/link.asp?id=X4X7L5K007HH2788>
p. 479-488
As in many anurans, males of the totally aquatic species, Xenopus
laevis, advertise their sexual receptivity using vocalizations.
Unusually for anurans, X. laevis females also advertise producing a
fertility call that results in courtship duets between partners.
Although all X. laevis calls consist of repetitive click trains, male
and female calls exhibit sex-specific acoustic features that might
convey sexual identity. We tested the significance of the carrier
frequency and the temporal pattern of calls using underwater playback
experiments in which modified calls were used to evoke vocal responses
in males. Since males respond differently to male and female calls, the
modification of a key component of sexual identity in calls should
change the male's response. We found that a female-like slow call rhythm
triggers more vocal activity than a male-like fast rhythm. A call
containing both a female-like temporal pattern and a female-like carrier
frequency elicits higher levels of courtship display than either feature
alone. In contrast, a male-like temporal pattern is sufficient to
trigger typical male–male encounter vocalizations regardless of spectral
cues. Thus, our evidence supports a role for temporal acoustic cues in
sexual identity recognition and for spectral acoustic cues in conveying
female attractiveness in X. laevis.
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