Mares Prefer the Voices of Highly Fertile Stallions

We investigated the possibility that stallion whinnies, known to encode caller size, also encoded information about caller arousal and fertility, and the reactions of mares in relation to type of voice. Voice acoustic features are correlated with arousal and reproduction success, the lower-pitched the stallion’s voice, the slower his heart beat and the higher his fertility. Females from three study groups preferred playbacks of low-pitched voices. Hence, females are attracted by frequencies encoding for large male size, calmness and high fertility. More work is needed to explore the relative importance of morpho-physiological features. Assortative mating may be involved as large females preferred voices of larger stallions. Our study contributes to basic and applied ongoing research on mammal reproduction, and questions the mechanisms used by females to detect males’ fertility.

我们探究了如下可能性：此前已知种公马的嘶鸣可传递发声个体的体型信息，本研究旨在明确其是否同时编码了发声者的唤醒状态与繁殖能力，以及母马对不同类型叫声的行为反应。叫声的声学特征与唤醒状态及繁殖成功率显著相关：种公马的叫声频率越低，其心率越缓，繁殖能力则越强。三个试验组的母马均更偏好低频播放的种公马嘶鸣。由此可见，母马会被传递出大型雄性体型、平静状态与高繁殖能力的声音频率所吸引。未来仍需开展更多研究，以厘清形态生理特征的相对重要性。鉴于体型较大的母马更偏好体型更大的种公马的叫声，这一现象可能涉及选型交配（assortative mating）。本研究为当前正在开展的哺乳动物繁殖基础与应用研究提供了新的支撑，并对雌性个体识别雄性繁殖能力所依赖的潜在机制提出了新的疑问。