Miller Reilly L, Kaser Francesca V E, Belmont Ryan E, Ennis Michael, Voss Kristofor A, Bolt Laura M, Schreier Amy L
Department of Biology, Regis University, Denver, CO, USA.
Department of Anthropology, University of Toronto Mississauga, Mississauga, ON, Canada.
Primates. 2025 Jan;66(1):117-127. doi: 10.1007/s10329-024-01160-6. Epub 2024 Oct 1.
Habitat loss due to deforestation is a primary threat to global biodiversity. Clearing tropical rainforests for agriculture or development leads to forest fragmentation. Forest fragments contain fewer large trees and provide lower food availability for primates compared to continuous forests. Mantled howler monkeys (Alouatta palliata) inhabit fragmented rainforests and may need to alter their activity budgets and spatial cohesion to mitigate competition and conserve energy in fragments where food quality is lower. We compared howler monkey activity and spatial cohesion across a small forest fragment (La Suerte Biological Research Station, LSBRS) and a large, continuous forest (La Selva Research Station) in Costa Rica. We predicted that monkeys at LSBRS would rest more, feed more, travel less, and be less spatially cohesive compared to La Selva to contend with fewer resources in the small fragment. Using instantaneous scan sampling at 2-min intervals during 30-min focal samples, we recorded activity and the number of individuals within 5 m of the focal animal. We collected 1505 h of data from 2017-2024. Monkey activity and spatial cohesion differed significantly across sites. As predicted, monkeys at LSBRS spent more time feeding than at La Selva, but contrary to our predictions, they rested less and traveled more. The mean number of individuals within 5 m was significantly lower at LSBRS compared to La Selva. The ability to modify their activity and spatial cohesion in response to fragmentation provides insight into how primates can contend with fewer resources and higher competition in changing ecosystems worldwide.
森林砍伐导致的栖息地丧失是对全球生物多样性的主要威胁。为了农业或发展而砍伐热带雨林会导致森林碎片化。与连续森林相比，森林碎片中的大树较少，为灵长类动物提供的食物也较少。披毛吼猴（Alouatta palliata）栖息在碎片化的雨林中，可能需要改变它们的活动预算和空间凝聚力，以减轻竞争并在食物质量较低的碎片中保存能量。我们比较了哥斯达黎加一个小森林碎片（拉苏埃拉生物研究站，LSBRS）和一个大的连续森林（拉塞尔瓦研究站）中吼猴的活动和空间凝聚力。我们预测，与拉塞尔瓦相比，LSBRS的猴子会更多地休息、更多地进食、更少地移动，并且空间凝聚力更低，以应对小碎片中较少的资源。在30分钟的焦点样本期间，每隔2分钟使用瞬时扫描抽样，我们记录了活动以及焦点动物5米范围内的个体数量。我们从2017年至2024年收集了1505小时的数据。不同地点的猴子活动和空间凝聚力存在显著差异。正如预测的那样，LSBRS的猴子进食时间比拉塞尔瓦的猴子更多，但与我们的预测相反，它们休息时间更少，移动更多。与拉塞尔瓦相比，LSBRS在5米范围内的个体平均数量显著更低。它们根据碎片化情况调整活动和空间凝聚力的能力，为了解灵长类动物如何在全球不断变化的生态系统中应对较少的资源和更高的竞争提供了思路。
