The Nutrient Intake Of Trachypithecus Francoisi Based On Geometric Framework

Animals need various nutrients to satisfy their nutritional requirements,and their feeding strategies are affected by nutritional requirements.We studied the relationship between nutrient contents and food choice of Fran?ois'langur Trachypithecus francoisi in limestone forest.We studied food selection of the animals using instantaneous scan sampling methods,and sampled food items for measuring nutritional contents from September 2016to August 2017 in Fusui,Chongzuo,Guangxi.Nutritional contents included water,crude lips,crude protein,acid detergent fiber(ADF),neutral detergent fiber(NDF)and minerals(Zn,Ca,K,Mg,Cu,Fe,Mn).The results indicated:1.animals used 23 species,with feeding proportion ranged from 0.02%to6.81%.In young leaves,there was significant difference in the K content between seasonal species(n=74)and rare species(n=38),so did ADF(P<0.01),there was no significant difference among other nutrient elements in young leaves(P>0.05).In fruit,there was significant difference in the Mn content between seasonal food(n=4)and rare food(n=12)(P<0.05),there was no significant difference among other nutrient elements in fruit(P>0.05).On seasonal species(n=74),there was significant difference in the Cu content between dry season(n=43)and rainy season(n=14),so did K content(P<0.05).there was no significant difference among other nutrient elements on seasonal species(P>0.05).On rare species(n=57),there was significant difference in the Cu content between dry season(n=43)and rainy season(n=14),so did NDF(P<0.05).During dry season,there was significant difference in the K content between seasonal species(n=47)and rare species(n=69),so did water and crude protein(P<0.05),there was no significant difference among other nutrient elements(P>0.05).During rainy season,there was significant difference in the ADF content between seasonal species(n=33)and rare species(n=23),so did crude protein(P<0.05),there was no significant difference among other nutrient elements(P>0.05).2.The generalized linear model(GLM)based on annual date showed that Ca(?=-2.156,P=0.012,w=20.395),Mg(?=5.374,P=0.003,w=17.472),Mn(?=18.636,P=0.010,w=20.200)and water content(?=0.238,P=0.007,w=26.028)had significant effects on the Fran?ois'langur feeding proportion.The Model averaging further indicated that the five nutritional contents,Ca(?=-2.190,P=0.005,W_ip=1.000),Mg(?=5.280,P=0.002,W_ip=1.000),Mn(?=17.207,P=0.012,W_ip=1.000),water content(?=0.222,P=0.005,W_ip=1.000)and crude protein content(?=-0.090,P=0.107,W_ip=0.800),significantly affected food choice of the animals(AIC=870.35,?AIC=0,df=7,W_i=0.27);The generalized linear model(GLM)based on rainy season date showed that Mg(?=7.415,P<0.001,w=23.737),Mn(?=19.379,P=0.006,w=18.009),Ca(?=-2.694,P=0.005,w=17.386)and water content(?=0.210,P=0.037,w=12.184)had significant effects on the Fran?ois'langur feeding proportion.The Model averaging further indicated that the four nutritional contents,NDF content(?=-0.332,P=0.015,W_ip=1.000),ADF content(?=0.179,P=0.018,W_ip=1.000)?K(?=-6.718,P=0.520,W_ip=0.410)and water content(?=0.269,p=0.381,W_ip=0.590),significantly affected food choice of the animals(AIC=271.86,?AIC=0,df=6,W_i=0.15).The generalized linear model(GLM)based on dry season date showed that NDF content(?=-0.380,P=0.021,w=25.628)and ADF content(?=0.241,P=0.011,w=25.580)had significant effects on the Fran?ois'langur feeding proportion.The Model averaging further indicated that the four nutritional contents,Mg(?=7.672,P<0.001,W_ip=1.000),Ca(?=-2.956,P<0.001,W_ip=1.000),Mn(?=17.005,P=0.011,W_ip=1.000),water content(?=0.192,P=0.032,W_ip=1.000)and crude protein content(?=-0.036,P=0.524,W_ip=0.410),significantly affected food choice of the animals(AIC=596.58,?AIC=0,df=7,W_i=0.150).3.The Geometric Framework based on annual date showed that,carbohydrates were the main nutrients in the food of Trachypithecus francoisi,and the energy contribution rate of energy supply was basically above 40%,the energy contribution rate of protein was below 40%,and the energy contribution rate of lipid was less than 40%,the rate was relatively stable between 0-20%;On seasonal species,carbohydrates were the main nutrients for energy,and the energy contribution rate was basically above 40%,the energy contribution rate of protein was below 40%,and the energy contribution rate of lipid was below40%.the energy contribution rate was basically less than 20%;On rare species,carbohydrates were the main nutrients for energy,the energy contribution rate was basically more than 40%,the protein energy contribution rate was below30%,and the lipid energy contribution rate was basically less than 20%;Linear regression results show that based on the annual food intake data of the Trachypithecus francoisi,the ratio of non-protein to protein(NPE/AP)energy intake was k=3.64,R²=0.705;During dry season,the ratio of NPE/AP energy intake was k=3.535,R²=0.709;During rainy season,the ratio of NPE/AP energy intake was k=3.781,R²=0.703.there was no significant difference in the NPE/AP between dry season and rainy season(P>0.05).The feeding strategies of Fran?ois'langur are affected by nutritional requirements.There was difference in the nutritional requirements of Fran?ois'langur between dry season an d rainy season,and ther e has seasonal variation.Like oth er primates,Trachypithecus francoisi try to maintain the ratio of NPE/AP for feeding.