Mammal Communication Lab, Department of Cognitive Biology, Althanstrasse 14, 1090, University of Vienna, Austria.
Sci Rep. 2017 Apr 19;7:46414. doi: 10.1038/srep46414.
Gaining information about conspecifics via long-distance vocalizations is crucial for social and spatially flexible species such as the African elephant (Loxodonta africana). Female elephants are known to discriminate individuals and kin based on acoustic cues. Specifically, females approached the loudspeaker exclusively with playbacks of familiar individuals with high association indexes, intentionally fusing with their affiliates. For males, which are less bonded, gathering social information via vocalizations could still have important implications, but little is known about their vocal discrimination skills. We experimentally tested the ability of male African elephants to discriminate the social rumbles of familiar (from the same population) versus unfamiliar females. Male elephants discriminated and preferentially moved towards the rumbles of unfamiliar females, showing longer attentive reactions and significantly more orientating (facing and approaching the speaker) behavior. The increased orientating response of males towards playbacks of unfamiliar females is converse to the reaction of female subjects. Our results provide evidence that male elephants extract social information from vocalizations, yet with a different intention than females. Accordingly, males might use social cues in vocalizations to assess mating opportunities, which may involve selection to identify individuals or kin in order to avoid inbreeding.
通过远距离的声音来获取同类的信息，对社会性强且空间分布灵活的物种来说至关重要，比如非洲象（Loxodonta africana）。众所周知，雌象可以根据声音线索来辨别个体和亲属。具体来说，雌象会专门用与高关联指数的熟悉个体的回放声来接近扩音器，有意与自己的亲属融合。而对于联系较少的雄性来说，通过声音获取社交信息可能仍然具有重要意义，但我们对它们的声音辨别能力知之甚少。我们通过实验测试了雄性非洲象辨别熟悉（来自同一群体）和陌生雌性的社交隆隆声的能力。雄性大象能够辨别并优先向陌生雌性的隆隆声移动，表现出更长的注意力反应和明显更多的定向（面对和接近扬声器）行为。雄性对陌生雌性回放的定向反应与雌性主体的反应相反。我们的研究结果表明，雄性大象从声音中提取社交信息，但目的与雌性不同。因此，雄性可能会利用声音中的社交线索来评估交配机会，这可能涉及到识别个体或亲属以避免近亲繁殖的选择。
