ABSTRACT

Previous research has shown that African lions (Panthera leo) have the ability to discriminate between conspecific vocalisations, but little is known about how individual identity is conveyed in the spectral structure of roars. Using acoustic – accelerometer biologgers that allow vocalisations to be reliably associated with individual identity, we test for vocal individuality in the fundamental frequency (f0) of roars from 5 male lions, firstly by comparing simple f0 summary features and secondly by modelling the temporal pattern of the f0 contour. We then assess the application of this method for discriminating between individuals using passive acoustic monitoring. Results indicate that f0 summary features only allow for vocal discrimination with 70.7% accuracy. By comparison, vocal discrimination can be achieved with an accuracy of 91.5% based on individual differences in the temporal pattern of the f0 sequence. We further demonstrate that passively recorded lion roars can be localised and differentiated with similar accuracy. The existence of individually unique f0 contours in lion roars and their relatively lower attenuation indicates a likely mechanism enabling individual lions to identify conspecifics over long distances. These differences can be exploited by researchers to track individuals across the landscape and thereby supplement conventional lion monitoring approaches.

摘要

先前的研究表明，非洲狮（Panthera leo）具有区分同种发声的能力，但人们对吼声的光谱结构如何传达个体身份知之甚少。使用声学 - 加速度计生物记录器，允许发声与个体身份可靠地相关联，我们测试了5 只雄狮咆哮的基本频率 ( f 0) 的声音个性，首先通过比较简单的f 0 摘要特征，其次通过对时间建模f 0 轮廓的图案。然后，我们评估了这种方法在使用被动声学监测区分个体方面的应用。结果表明f0 摘要特征仅允许以 70.7% 的准确率进行语音识别。相比之下，基于f 0 序列的时间模式的个体差异，可以以 91.5% 的准确度实现声音识别。我们进一步证明，被动记录的狮子吼声可以以相似的精度进行定位和区分。狮子吼声中存在个体独特的f 0 轮廓及其相对较低的衰减表明一种可能的机制使个体狮子能够长距离识别同种。研究人员可以利用这些差异来跟踪整个景观中的个体，从而补充传统的狮子监测方法。