Anthropogenic forest fragmentation impacts many aspects of animal behaviour, including feeding ecology. With forests increasingly fragmented in tropical regions due to human development, the proportion of forest edge (≤ 100 m from clear-cut regions) is higher relative to forest interior. Forest edges differ in vegetation from interior, making it important to better understand how anthropogenic edges impact the feeding behaviour of primates such as mantled howler monkeys (Alouatta palliata). We predicted that howler monkeys would feed on higher-quality plant resources, from a larger number of tree families, and from larger trees in forest interior compared to anthropogenic forest edge. We surveyed howler monkey feeding behaviour across forest zones in a fragmented rainforest in Costa Rica, La Suerte Biological Research Station. We observed individual monkeys for 30-minute periods, collecting data on their feeding behaviour and tree use at 2-minute intervals. We measured feeding trees and recorded the plant parts and taxonomy of resources consumed. Monkeys consumed more leaves and fewer stems and fed from a smaller number of tree families in the forest interior, while they consumed fewer leaves and more stems and fed from a larger number of tree families in the forest edge. Monkeys also fed from larger, taller trees in the forest interior than the edge. The differences in howler monkey feeding behaviour between forest zones attest to the impact of human disturbance on howler monkey feeding ecology.

人为森林破碎化影响动物行为的许多方面，包括饲养生态学。由于人类的发展，热带地区的森林日益破碎化，森林边缘（距净采区≤100 m）的比例相对于森林内部而言更高。森林边缘的植被与内部不同，因此更好地了解人为边缘如何影响灵长类动物的摄食行为非常重要，例如披风吼猴 ( Alouatta palliata）。我们预测，与人为森林边缘相比，吼猴会以更高质量的植物资源为食，这些植物资源来自更多的树科，以及森林内部较大的树木。我们在哥斯达黎加的 La Suerte 生物研究站调查了跨越森林区域的吼猴的进食行为。我们对每只猴子进行了 30 分钟的观察，每隔 2 分钟收集一次有关它们的进食行为和树木使用情况的数据。我们测量了喂养树木并记录了植物部分和消耗资源的分类。猴子消耗更多的叶子和更少的茎，并从森林内部的较少数量的树科中取食，而它们消耗的叶子和茎较少，并从森林边缘的更多树科中取食。猴子也从较大的，森林内部比边缘高的树木。林区之间吼猴觅食行为的差异证明了人类干扰对吼猴觅食生态的影响。