Interdisciplinary Program of EcoCreative, Ewha Womans University, Seoul, 03760, Republic of Korea.
Laboratory of Animal Behaviour and Conservation, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China.
Sci Rep. 2023 May 22;13(1):8285. doi: 10.1038/s41598-023-34913-2.
Natal dispersal is an important life-history trait in all animal taxa. In pair-living species, parent-offspring competition derived from the offspring's maturity can motivate the natal dispersal of offspring. However, not much has been known about the dispersal mechanisms of pair-living gibbons. To test food and mate competition as potential reasons for dispersal, we investigated the effect of the offspring age and sex on relationships between parents and offspring in wild Javan gibbon (Hylobates moloch) in Gunung Halimun-Salak National Park, Indonesia. We collected behavioral data for two years between 2016 and 2019. We found that aggression from parents toward offspring increased in both feeding and non-feeding context as the offspring got older. Offspring received more aggression from the parent of the same sex in the general context. While offspring decreased co-feeding and grooming time with parents as they got older, there was no change in the proximity and approach to parents. The results imply the presence of both intra-group food and mate competition which increase with the offspring's age. We highlight that increased competition between maturing offspring and parents changes their social relationships and peripheralizes offspring from the natal group which will eventually motivate offspring to disperse in Javan gibbons.
自然扩散是所有动物类群的一个重要生活史特征。在对偶居物种中，由于后代的成熟而产生的亲代-后代竞争，可以促使后代进行自然扩散。然而，对于对偶居长臂猿的扩散机制，我们知之甚少。为了检验食物和配偶竞争是否可能是扩散的原因，我们在印度尼西亚的 Gunung Halimun-Salak 国家公园研究了野生爪哇猩猩（Hylobates moloch）中后代的年龄和性别对亲代和后代关系的影响。我们在 2016 年至 2019 年之间收集了两年的行为数据。我们发现，随着后代年龄的增长，父母对后代的攻击在喂食和非喂食环境中都有所增加。在一般情况下，同性别的父母对后代的攻击性更大。虽然后代与父母的共同进食和梳理时间随着年龄的增长而减少，但与父母的接近和接近程度没有变化。结果表明，随着后代年龄的增长，种内食物和配偶竞争都在增加。我们强调，成熟后代与父母之间竞争的加剧，改变了他们的社会关系，并使后代与出生地群体疏远，这最终将促使爪哇猩猩的后代进行扩散。
