Nutritional Contents Of Dry Season And Its Influences On Food Choice Of White-headed Langur And Francois’ Langur

Food is the source of the life energy, and is the basic condition for the survival of animals. Nutritional factor is one of the most important influences on primate food choice. The white-headed langur (Trachypitheucs leucocephalus) and the francois langur (T. francoisi) are two of the few primates inhabiting in karst habitast. Karst habitat has some unique features, such as lack surface water, and low vegetation coverage. Because of the lack of the plant resources in the dry season, Do the feeding behaviors of white-headed langurs and francois langurs influcenced by nutritional components of foods? In this study, we explore the relationship between the nutritional components of white-headed langurs and francois langurs’foods with their food choices in the dry season. The main results are as follows:1. The relationships between the nutritional components of white-headed la’gurs’ foods with their food choice in the dry seasonWe collected samples of14major food species in the dry season and5lesser-used food species of white-headed langurs at Fusui Nature Reserve, Guangxi, China, between October2010and March2011. We determined the nutrient content of water, crude fat, crude protein (CP), crude fiber(CF), minerals (Ca、Zn、Fe、Mn), and calculated the ratio of crude protein and crude fiber (CP/CF) of each sample, and compared nutritional components and the CP/CF ration of major food species versus lesser-used food species using Mann-Whitey U tests. The results indicated that no difference was found for water, crude fat, crude protein, crude fiber, minerals (Ca、Zn、Fe、Mn) and the CP/CF ration between major food species and the lesser-used food species. We also used Spearman Rank correlations to examine the relationship between nutritional data of sampled food species and their proportion in the diet. The results indicated that there was no significant correlation between the content of water, crude fat, crude protein, crude fiber, minerals(Ca、Zn、Fe、Mn), the CP/CF ration of the major and lesser food species and their proportion in the diet. These suggested that food choice of white-headed langurs in the dry season was not influenced by the content of water, crude fat, crude protein, crude fiber, minerals (Ca、Zn、Fe、Mn) and the CP/CF ration in the foods.2. The relationships between the nutritional components of francois langurs’food with their food choice in the dry seasonWe collected samples of12major food species and26lesser-used food species of Francois’ langurs in the dry season at Nonggang Nature Reserve, Guangxi, China, on November2005. We determined the nutrient content of water, crude fat, crude protein (CP), crude fiber(CF), acid detergent fiber (ADF), neutral detergent fiber (NDF), minerals (Ca, Mg、Cu、Zn、Fe、Mn), and calculated the ratio of crude protein and acid detergent (PROT/ADF) of each sample, and tested differences between major food species and lesser-used food species in nutritional data and the PROT/ADF ration via One-way ANOVA. The results indicated that there was no significant difference between the major and lesser-used species in nutritional contents and the PROT/ADF ration, except for the water content. The water content of the major food species was significant higher than that of the lesser-used species. We also tested the correlations between nutritional data of sampled food species and their proportion in the diet. The results indicated that there was no significant correlation between the nutritional contents and the PROT/ADF ration of major and lesser-used species and their feeding proportion, except for the water content. A significant and positive correlation was found between water content of food species and their feeding proportion. these suggested that the water content in the foods influenced the food choice of Francois’ langurs at Nonggang Nature Reserve in the dry season.