Seasonal Variation Of Main Nutrients In Food Of Fran?ois' Langur And White-headed Langur In Fusui County,Guangxi

Fran?ois' langur(Trachypithecus francoisi)and White-headed langur(T.leucocephalus)are unique primates inhabiting in the limestone habitat in Fusui County,Guangxi.White-headed langur and Fran?ois' Langurs are close relatives,but the habitat of them are divided by rivers.Their physiological structure is similar,and t heir plant parts and food types are highly similar.In order to provide the necessary data and the theoretical basis for the protection of these two rare primates,it is important to analyze seasonal variation and similarity of nutrients and the influences on feeding patterns between the two langur using the same method during the same period.From September 2016 to August 2017,the food of two langurs was collected systematically,and the nutrient composition of their food was determined.The results are as follows:1.Crude protein content(rainy season: 19.82±5.07 % VS dry season: 17.82±5.67%)?neutral detergent fiber content(rainy season: 15.64±6.58% VS dry season: 14.38%±6.01%)?acid detergent fiber content(rainy season: 15.36±5.61% VS dry season: 13.01±5.16%)?ash content(rainy season:10.14±3.41% VS dry season: 10.71±4.06%)in the diet of the white-headed langurs did not differ(p > 0.05)between the dry and rainy seasons,but there are significant differences in water content(rainy season: 77.43±6.35% VS dry season: 72.43±7.33%)(p < 0.05)and crude fat conten(rainy season: 10.55±2.50% VS dry seasons: 12.52±2.10%)(p < 0.01).Crude protein content(spring:19.50±6.58%;summer: 19.60±5.79%;autumn: 18.24±6.87%;winter: 16.15±5.69%)?water content(spring: 75.28±6.8%;summer: 76.76±7.12%;autumn: 74.64±7.85%;winter: 72.23±8.06%)?neutral detergent fiber conten(spring: 15.75±7.29%;summer: 15.94±6.39%;autumn: 16.81±6.57%;winter: 14.05±8.09%)?acid detergent fiber content(spring: 12.04±5.43%;summer: 14.94±5.13%;autumn: 15.33±7.29%;winter: 14.58±5.35%)?ash content(spring: 10.74±6.48%;summer: 11.23±6.07%;autumn: 9.92±3.97%;winter: 10.48±4.41%)did not significantly different(p > 0.05)among four seasons.There was a difference(p < 0.05)in the crude fat content of the feeding plants of the white-head langurs,and the crude fat content in summer(8.76±3.2%)was lower than that in spring(12.17±3.17%),autumn(13.46±3.13%)and winter(12.6±2.81%).Crude protein content(rainy season: 18.88±5.18% VS dry season: 16.25±5.38%)?water content(rainy season: 74.37±7.26% VS dry season: 72.53±8.04%)?crude fat conten(rainy season:12.01±2% VS dry seasons: 12.16±3.04%)and ash content(rainy season: 9.62±2.98 VS dry season:9.68± 3.63%)in the diet of the fran?ois' langur did not differ(p > 0.05)between the dry and rainy seasons,but there is significant differences(p < 0.05)in neutral detergent fiber content(rainy season: 17.83± 7.69% VS dry season: 14±6.81%)and acid detergent fiber content(rainy season:17.01± 6.05% VS dry season: 12.75±7.09%).crude fat content neutral(spring: 13.14±3.13%;summer: 12.10±4.8%;autumn:12.41±1.83%;winter: 12.2±3%)?neutral detergent fiber conten(spring: 18.07±6.91%;summer: 16.36±6.73%;autumn: 16.29±8.09%;winter: 16.47±9.54%)?acid detergent fiber content(spring: 13.97±7.10%;summer: 17.41±8.96%;autumn: 15.4±6.29%;winter: 15.43±9.1%)?ash content(spring: 10.27±3.25%;summer: 10.58±2.77;autumn: 9.54± 3.5%;winter: 11.06±4.38%)did not significantly different(p > 0.05)among four seasons,but Crude protein content(spring: 19.07±6.36%;summer: 19.03±4.65%;autumn: 18.22±6.3%;winter: 13.92±3.89%)and water content(spring: 76.48±6.87%;summer: 76.08±7.74%;autumn: 73.26±7.36%;winter: 70.04±7.69%)with seasonal variation(p < 0.05).2.The contents of nutrients in the food of fran?ois' langur and white-headed langur were similar.Except for the difference in crude fat content between summer and autumn(Z =-2.32,p = 0.02),there was no difference in the contents of crude protein,water,crude fat,neutral detergent fiber,acid detergent fiber and ash.3.The Generalized linear model was used to analyze the relationship between the nutrition components(crude protein,water,crude fat,neutral detergent fiber,acid detergent fiber and ash content)and the feeding ratio of white-headed langurs and fran?ois' langurs.It was found that water did not affect the food selection of fran?ois' langurs and white-headed langurs(p > 0.05).Crude protein will affect the fran?ois' langurs on the choice of food(p < 0.05)in spring and winter,did not affect the white-headed langurs on the choice of food(p > 0.05).Crude fat did not influence the food selection of fran?ois' langurs and white-headed langurs(p > 0.05).Neutral washing fiber did not affected the food selection of fran?ois' langurs and white-headed langurs(p > 0.05),while acid washing fiber did not affected the food selection of white-headed langurs(p > 0.05)but affected the food selection of fran?ois' langurs(p < 0.05)in winter.Ash content did not affect the food selection of the fran?ois' langurs and white-headed langurs(p > 0.05),indicating that there was a high similarity between the influence of food nutrients on the food selection of the white-headed langurs and that of the fran?ois' langurs,that is the food selection strategies were similar.