Askew James A, Morrogh-Bernard Helen C
Jane Goodall Research Center, Department of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, CA, USA.
Folia Primatol (Basel). 2016;87(5):305-319. doi: 10.1159/000452304. Epub 2016 Dec 9.
Acoustic characteristics and context of the long-distance call of male orang-utans (Pongo pygmaeus wurmbii) were examined in a population of orang-utans from Central Kalimantan, Borneo. Male orang-utans produced long calls under different circumstances, including calls made spontaneously, in response to conspecifics, when accompanied by a snag crash and when travelling with a female. It was shown by acoustic analyses that there was individual discrimination between the male's calls, discrimination between the calls made under different contexts, and between calls from one individual from different years, which coincided with a change in his dominance status. We also confirm that flanged male orang-utans advertise their intended travel route, by long calling in the direction of their travel. If other orang-utans (males and females) within ear shot of the caller can identify the caller from their long call, and even obtain information about the context and status of the individual, they can then therefore choose whether to approach or avoid them. Thus, males seem to be using their long call to announce their presence, allowing them to orient themselves spatially to other orang-utans, and, potentially, to co-ordinate a network of loose associations between both males and females in the area.
在婆罗洲加里曼丹中部的一群猩猩中，对雄性苏门答腊猩猩（Pongo pygmaeus wurmbii）长途呼叫的声学特征和背景进行了研究。雄性苏门答腊猩猩在不同情况下发出长途呼叫，包括自发发出的呼叫、对同种个体做出回应时发出的呼叫、伴随断枝碰撞声时发出的呼叫以及与雌性同行时发出的呼叫。声学分析表明，雄性的呼叫之间存在个体差异，不同背景下发出的呼叫之间存在差异，同一个体不同年份发出的呼叫之间也存在差异，这与它的优势地位变化相吻合。我们还证实，有颊垫的雄性苏门答腊猩猩会朝着它们的行进方向发出长途呼叫，以此来表明它们的行进路线。如果在呼叫者听力范围内的其他猩猩（雄性和雌性）能够通过其长途呼叫识别出呼叫者，甚至获取有关该个体的背景和地位的信息，那么它们就可以据此选择是接近还是避开呼叫者。因此，雄性似乎是在利用它们的长途呼叫来宣告自己的存在，使它们能够在空间上与其他猩猩定位自己的位置，并有可能协调该地区雄性和雌性之间的松散联系网络。
