Charlton Benjamin D, Reby David, McComb Karen
Department of Psychology, School of Life Sciences, University of Sussex, BN1 9QH, United Kingdom.
J Acoust Soc Am. 2008 May;123(5):2936-43. doi: 10.1121/1.2896758.
Studying female response to variation in single acoustic components has provided important insights into how sexual selection operates on male acoustic signals. However, since vocal signals are typically composed of independent components, it is important to account for possible interactions between the studied parameter and other relevant acoustic features of vocal signals. Here, two key components of the male red deer roar, the fundamental frequency and the formant frequencies (an acoustic cue to body size), are independently manipulated in order to examine female response to calls characterized by different combinations of these acoustic components. The results revealed that red deer hinds showed greater overall attention and had lower response latencies to playbacks of roars where lower formants simulated larger males. Furthermore, female response to male roars simulating different size callers was unaffected by the fundamental frequency of the male roar when it was varied within the natural range. Finally, the fundamental frequency of the male roar had no significant separate effect on any of the female behavioral response categories. Taken together these findings indicate that directional intersexual selection pressures have contributed to the evolution of the highly mobile and descended larynx of red deer stags and suggest that the fundamental frequency of the male roar does not affect female perception of size-related formant information.
研究雌性对单一声学成分变化的反应，为性选择如何作用于雄性声学信号提供了重要见解。然而，由于声音信号通常由独立成分组成，考虑所研究参数与声音信号其他相关声学特征之间可能的相互作用很重要。在此，雄性马鹿吼声的两个关键成分，即基频和共振峰频率（身体大小的声学线索），被独立操控，以检验雌性对以这些声学成分不同组合为特征的叫声的反应。结果显示，当较低共振峰模拟较大雄性时，母马鹿对吼声回放表现出更高的总体关注度且反应潜伏期更短。此外，当雄性吼声的基频在自然范围内变化时，雌性对模拟不同大小雄性的吼声的反应不受影响。最后，雄性吼声的基频对任何雌性行为反应类别均无显著单独影响。综合这些发现表明，定向的两性间选择压力促成了雄性马鹿高度灵活且位置较低的喉部的进化，并表明雄性吼声的基频不会影响雌性对与大小相关的共振峰信息的感知。
