Research On The Feeding Habits Of Wild Elk In Dafeng And The Nutritional Analysis Of Their Staple Food Plants

In this study,we want to uncover the diet of wild-release Pere Davids deer Elaphurus davidianus compared with that of quasi-wild Pere David's deer(in the first and second core area)in Dafeng Milu National Nature Reserve and other regions from November,2011 to December,2014.1.Field observation,evidence of feeding on forage,fecal microhistology and stable isotope analysis of carbon and nitrogen were used to analyze the staple diet composition and dynamics of Pere David's deer,and the results revealed that Spartina alterniflora,Phragmites australis,Imperata cylindrica var.major,Pennisetum alopecuroides,Erigeron annuus,Suaeda glauca,etc.were the staples of wild-release Pere David's deer.They were all herbage plants belonging to Gramineae,Compositae and Chenopodiaceae and percentage of gramineous plants was 66.7%.Gramineous plants were staples of wild-release Pere David's deer throughout the year.Spartina alterniflora made a lower proportion(46.13%)in diet composition of wild-release Pere David's deer in spring,and the proportion(55.33%)began to rise in summer,and was highest(74.12%,54.34%)in autumn and winter;Phragmites australis made a higher proportion(46.72%)in diet composition of wild-release Pere David's deer in spring,then reduced(28.12%)in summer,and was lowest(19.41%,29.76%)in autumn and winter,which was just the opposite.There was no significant difference in plant species consumed by wild-release Pere David's deer in different seasons,but the proportion of staples were significantly different throughout the year.The distribution of stable carbon and nitrogen isotope values revealed that there were C3 plants and C4 plants in diet of wild-release Pere David's deer.C4 plants made a higher proportion(e.g.,70.36%in summer).The changing trend of proportion of C3 plants and C4 plants was basically same as that of Phragmites australis(C3 plant)and Spartina alterniflora(C4 plant).2.Compared to diets of the Pere David's deer in other regions,Pennisetum alopecuroides and Imperata cylindrica var.major were staples of quasi-wild Pere David's deer in Dafeng Milu National Nature Reserve in summer,they were all belonging to C4 plants.The percentages of Pennisetum alopecuroides in the first and second core area were 40.56%?28.67%and that of Imperata cylindrica var.major were 43.46%?49.60%.Staples of wild-release Pere David's deer were different from that of quasi-wild Pere David's deer and the former had a higher proportion of C3 plants(Mann-Whitney U-test,Z=-6.751,P<0.001).In winter,dicotyledonous plants made a higher proportion in supplementary feeding of quasi-wild Pere David's deer in the first and second core area of Dafeng Milu National Nature Reserve and in Beijing Milu Park Museum,the percentages of above items were 50.87%,52.58%,47.18%respectively.But Pere David's deer in Shishou Milu National Nature Reserve,Hubei Province,China with abundant food plants in diet had no need for supplementary feeding,staples of Pere David's deer here were Phragmites australis,Cynodon dactylon,Carex,Carpesium abrotanoides,Polygonum lapathifolium,Oenanthe javanica and other gramineous plants.Among them,gramineous plants made a higher proportion(59.95%)in diet.3.Moreover,according to nutritional analysis of staples and non-staples of Pere David's deer distributed mainly in Dafeng Milu National Nature Reserve,the result showed that:(1)Staples of wild-release Pere David's deer had lower crude protein,salinity and crude fat level(Mann-Whitney U-test,Z=-3.225,P=0.001;Z=-3.706,P<0.001;t-test,t=-2.719,df=67,P=0.008)and higher soluble saccharides,hemicellulose and cellulose level(Mann-Whitney U-test,Z=-2.869,P=0.004;Z=-3.385,P=0.001;Z=-4.811,P<0.001)than non-staples.(2)The upper leaves of Spartina alterniflora,Phragmites australis and Erigeron annuus had higher crude protein level(Wilcoxon test,Z=-3.920,P<0.001;Paired t-test,t=11.156,df=5,P<0.001;t=30.552,df=3,P<0.001),and upper leaves of Spartina alterniflora and Phragmites australis had higher crude fat level(Paired t-test,t=4.896,df=19,P<0.001;t=3.401,df=5,P=0.019),and upper leaves of Spartina alterniflora had lower hemicellulose and cellulose level(Wilcoxon test,Z=-2.203,P=0.028;Paired t=est,t=-3.779,df=19,P=0.001)than stems.Overall,the upper leaves had higher crude protein and crude fat level and lower hemicellulose and cellulose level than stems of staples of wild-release Pere David's deer.(3)Staples of wild-release Pere David's deer had lower crude fat,hemicellulose and cellulose level(Mann-Whitney U-test,Z=-5.289,P<0.001;Z=-2.989,P=0.003;Z=-4.878,P<0.001),but only higher soluble saccharides and salinity level(Mann-Whitney U-test,Z=-4.789,P<0.001;Z=-4.139,P<0.001 Mann-Whitney U-test,Z=-4.789,P<0.001;Z=-4.139,P<0.001)than that of quasi-wild Pere David's deer.(4)Spartina alterniflora had higher salinity level than Phragmites australis and Erigeron annuus(One-way ANOVA,F2,57=15.647,P<0.001).