Abstract: The study of of the effect of food energy content on non-human primate food choice has been an important component of nutritional ecology. We studied the relationship between food energy content and food choice of François’ langur Trachypithecus francoisi in limestone habitat. We surveyed langurs with focal animal sampling and continuous recording techniques. We analyzed food energy content by calorimeter. The results showed that immature leaves were the dominant food item (58.5%), with fruits, mature leaves, seeds, flowers, and bark comprising the rest of the diet (12.4% ,12.1%, 10.6%, 4.3%, 2.4%, respectively). Diet varied among the plant types, with arborial sources accounting for 48.5% of the diet, followed by those from shrubs 34.6%, lianas 19.4% and herbs 17.2%. The total average food energy content was 17.09 kJ/g, with monthly mean energy content ranging from 16.52 kJ/g to 17.61 kJ/g. Energy content varied among plant parts: seeds contained the largest energy content (19.52 kJ/g) whilst mature leaves had the lowest (16.84 kJ/g). Energy content varied among plant types, with shrubs having the largest energy content (17.52 kJ/g) and herbs having the lowest (15.73 kJ/g). Energy content varied significantly among food samplesand plants, as well as between the fifteen most preferred food species and the fifteen least preferred ones (P < 0.001); but such variations were not found between months, or between rainy seasons and drought seasons (P > 0.05). There was no significant relationship between species energy content and feeding time of langurs (P >0.05). This suggests food energy content was not the main factor influencing food choice of the langur. Food choice strategy of the François’ langur requires more rigorous testing.

Key words: Adaptation, Energy content, Energy strategy, Food choice, Trachypithecus francoisi

摘要： 能量对灵长类食物选择的影响是营养生态学中重要的组成部分。为了研究黑叶猴食物能量及其对食物选择的影响，采用焦点动物取样法和连续记录法在广西扶绥观察记录野生黑叶猴的觅食行为；每月观察结束后采集被取食的植物部位样本，利用全自动氧弹热量计测定其能量。结果表明，黑叶猴食物中嫩叶最高（58.5%），其次为果实（12.4%），其他种类依次为成熟叶（12.1%）、种子（10.6%）、花（4.3%）和树皮（2.4%）。在不同的生活型食物中，乔木占48.5%，灌木占34.6%，藤本和草本分别占19.4%和17.2%。各种食物平均能量为17.09 kJ/g，月平均能量在16.52 -17.61 kJ/g之间变化。种子的能量最高，达19.52 kJ/g，最低为成熟叶，仅为16.84 kJ/g。不同生活型植物中，灌木能量最高，达17.52 kJ/g，草本植物最低，仅为15.73 kJ/g。不同植物种类之间能量有显著的差异（P < 0.001）。取食量最多的15种和最少的15种植物之间平均能量有显著差异（P < 0.001），但在月份间、雨季和旱季间则无显著差异（P > 0.05）。取食不同种类的时间与其平均能量之间无显著相关关系（P = 0.40），食物能量含量并非影响黑叶猴食物选择的主要原因，其觅食策略需要进一步的研究。

关键词: 黑叶猴, 食物选择, 能量, 适应性, 能量对策