Dietary responses to the habitat heterogeneity resulting from anthropogenic disturbance vary among primates. Some species alter their foraging strategy and continue to thrive in human-modified habitats while others are unable to modify their diets sufficiently to cope with such disturbance. Over a 12-mo period, we investigated the feeding ecology of the Omo River guereza (Colobus guereza guereza), a subspecies of black-and-white colobus monkeys endemic to Ethiopia, in a large continuous forest (Munessa: LC group), a smaller modified continuous forest (Wondo Genet: SC group), and a tiny forest fragment (Aregash: F group). We found that the forest fragment had higher tree stem densities but lower overall tree basal area than the continuous forests. In all three forests, guerezas were mostly folivorous (LC group: 83%; SC group: 65%; F group: 62%) and consumed young leaves in accordance with their availability. However, in addition to these broad dietary similarities, there were several differences between forests suggesting strategies guerezas may use to cope with habitat heterogeneity in southern Ethiopia. We found that guerezas in anthropogenically altered forests relied less on mature leaves and more on whole fruits (F group) or flowers (SC group) than guerezas in large continuous forest (LC group). Guerezas also devoted large percentages of their feeding time to exotic species in disturbed forests (SC group: 49.0%; F group: 20.6%) but not in the large continuous forest (LC group: 0.0%). Lastly, guerezas in disturbed forests had richer diets (F group, N = 37 species, SC group, N = 32) than those in the large continuous forest (LC group, N = 27). Thus, our study found that within the folivorous dietary strategy of guerezas, there is considerable dietary variability among even neighboring populations experiencing different degrees of habitat fragmentation and degradation. This dietary flexibility may explain the relatively high tolerance of guerezas to human disturbance across their geographic distribution.

饮食对人为干扰引起的栖息地异质性的反应在灵长类动物之间有所不同。一些物种改变了它们的觅食策略，并在人类改良的栖息地中继续繁衍生息，而另一些物种则无法充分改变其饮食结构以应对这种干扰。在12个月的时间内，我们调查了Omo河guereza（Colobus guereza guereza），埃塞俄比亚特有的黑白疣猴属的一个亚种，在一个大型的连续森林（Munessa：LC组），一个较小的改良型连续森林（Wondo Genet：SC组）和一个很小的森林碎片（Aregash：F组）。我们发现，与连续森林相比，森林碎片具有较高的树茎密度，但总的树木基础面积却较低。在这三个森林中，guerezas大多是有叶的（LC组：83％； SC组：65％； F组：62％），并根据其可用性消耗了幼叶。但是，除了这些广泛的饮食相似性之外，森林之间还存在一些差异，这表明guerezas可以用来应对埃塞俄比亚南部的生境异质性。我们发现，人为改变的森林中的guerezas与大型连续森林（LC组）相比，对成熟叶子（F组）或花朵（SC组）的依赖更少，而对整个果实（F组）或花朵（SC组）的依赖更大。游击队还把大部分的采食时间用于受干扰的森林中的外来物种（SC组：49.0％； F组：20.6％），而不是大型连续林（LC组：0.0％）。最后，动乱的森林中的guerezas饮食丰富（F组，N = 37种，SC组，N = 32），比大型连续林（LC组，N = 27）。因此，我们的研究发现，在guerezas的叶面饮食策略中，即使是经历不同程度生境破碎和退化的邻近人群，其饮食也存在很大差异。这种饮食上的灵活性可能解释了游击球在其地理分布范围内对人类干扰的相对较高的耐受性。