Abstract: Few mammals feed on eucalyptus and wild white-headed langurs (Trachypithecus leucocephalus) have been found eating parts of this poisonous trees. From August 2021 to July 2022, data on the feeding on cultivated eucalyptus (Eucalyptus urophylla×E. grandis) were collected systematically from one free-ranging group of white-headed langurs in the Chongzuo White-headed Langur National Nature Reserve, Guangxi. We explored possible reasons why the whiteheaded langur feeds on eucalyptus by nutritional analysis. The results showed that white-headed langurs fed on barks, mature leaves, and young leaves of eucalyptus, accounting for 70. 4%, 28. 1% and 1. 4% of the total foraging time of eu-calyptus respectively. The mean durations of feeding bouts on barks and mature leaves were significant longer than that for young leaves. The frequencies of feeding bouts on bark and mature leaves were significantly higher in the rainy season than those in the dry season. The frequencies and mean duration of feeding bouts on barks, mature leaves, and young leaves of eucalyptus did not differ among ages of individuals. Compared to the young leaves of eucalyptus and the other major food plant species consumed by white-headed langurs, eucalyptus barks contain higher content of calcium, which indicates that the acquisition of mineral elements may be one of reasons to select eucalyptus as food.

Key words: White-headed langur, Eucalyptus urophylla×E. grandis, Nutrition, Mineral element

摘要： 自然界中很少有哺乳动物以桉树为食源植物。野外观察发现白头叶猴(Trachypithecus leucocephalus)常年取食人工种植的尾巨桉(Eucalyptus urophylla×E.grandis)，这是否是一种反常现象？2021年8月至2022年7月，以广西崇左白头叶猴国家级自然保护区内的一群白头叶猴为研究对象，系统收集其相关的取食人工种植尾巨桉的数据，通过对桉树被取食部位的营养分析，探讨影响白头叶猴取食桉树的因素。结果表明：白头叶猴取食桉树的部位包括树皮、成熟叶和嫩叶，分别占白头叶猴桉树总取食时间的70.4%、28.1%和1.4%，对树皮和成熟叶的取食行为回合平均持续时间明显长于嫩叶。雨季白头叶猴取食树皮和成熟叶的取食行为回合次数明显高于旱季。白头叶猴不同年龄组个体对桉树各部位的取食行为回合频次和平均持续时间均不存在显著性差异。与白头叶猴其他主要采食植物的嫩叶相比，桉树树皮中含有更多的钙元素，这提示钙质的获取可能是吸引白头叶猴取食桉树树皮的原因之一。

关键词: 白头叶猴, 尾巨桉, 营养, 矿质元素