| The size and variation of home range is an important parameter which can measure the quality and bearing capacity of zootope and estimate the habitat area for the minimum viable population.Habitat selection is the emphasis and hot point for ecological study,reflecting the response of animals to heterogeneous environments.16 Milu individuals(Elaphurus davidianus)from Dafeng Milu National Nature Reserve,Jiangsu province,were released in East Dongting Lake National Nature Reserve,Hunan province in March 3rd,2016.Study on home range and autumn-winter habitat selection of Milu at the early stage of reintroduction in Dongting lake area will promote the in-situ conservation and habitat monitoring for reintroduced Milu population.Moreover,it is beneficial to long-term selfmainte nance of natural re-wild Milu populations and is of great theoretical value and practical significance for the successful introduction of the other endangered animals under the background of high intensity human activities.Research subjects in this research were the first long-distance released Milu populations in China,however,study about initial home range and habitat selection of long-distance released Milu hasn't been reported yet.GPS satellite tracking technology,combined with ground tracking method were used to observe the released Milu population in Dongting lake area from March 3rd,2016 to February 28th,2017.According to the coordinate information transmitted from GPS satellite tracking collars,activity location data of 11 collared Milu(one male;ten females)was got to calculate the home range area by using MCP.Whether in autumn or winter,33 habitat utilization quadrats and 33 compared quadrats were surveyed from October 2016 to January 2017.The main results of this study are as follows:1.Home range of released Milu at the early stage of reintroduction(1)The initial home range of Milu released in Dongting lake area can be divided into four types,and the MCP home range size is 25.45-228.67 km2.There were extremely significant differences in the home range size among different individuals(t=3.767,P<0.01).(2)The variation of home range in different seasons of released Milu conforms to winter>autumn>spring>summer,and it varied greatly among different seasons(df=3,P<0.01).The seasonal variation of the home range size of released Milu was closely related to the seasonal changes of habitat.The primary influence factors may be the seasonal variation about the richness and availability of food resources,the variation of water lever of Dongting Lake and the human disturbance.(3)The home range size of released Milu had extremely significant difference among different months(df=11,P<0.01),so did females(df=11,P<0.01).Home area size was the largest in November,and the smallest in October for released Milu;For females,home area size was the largest in November,and the smallest in June.(4)There were significant difference between breeding season and non breeding season for the home range size of released Milu(t=-3.589;df=4;P<0.05).The home range size in non breeding seasons(104.69 ±25.64 km2)is greater than that in breeding season(10.05±0.85 km2)obviously.The primary reason is that in the breeding seasons,Milu consume a large amount of energy for estrus,which lead to a poor athletic ability and a small home range.(5)There were significant difference between dry season and wet season for the home range size of released Milu(P<0.01).The home range size in dry season(93.46 ± 23.30 km2)is greater than that in wet season(27.69 ± 0.97 km2)obviously.Thus,the correlation between the home range size and water level of Dongting Lake is proved indirectly,and the flood influences the migration of released Milu.2.Characteristic of habitat selection in autumn and winter(1)There were extremely significant difference between autumn and winter of the selection of vegetation types for released Milu(?2=55.123,df=5,P<0.01).In autumn,released Milu select the vegetation by random without any direction(?2=6.616,df=5,P>0.05).But in winter,they prefer the type near pools,use the herbaceous swamp randomly,avoiding shrub grass(?2=10.071,df=2,P<0.01).(2)There were extremely significant difference between autumn and winter on the 7 factors including food abundance,herbage coverage,arbor coverage,distance to road,distance to human settlement,distance to shelter,and the hidden level for released Milu(P<0.01).There was no significant difference in distance to water only(P>0.05).Canonical discriminant function including "distance to human settlement"as ecological factors can be used to distinguish the habitat selection of released Milu in autumn and winter.In autumn,released Milu prefer the habitat that of lower hidden lever,higher food abundance,higher herbage coverage,closer to shelter.There were extremely significant difference between utilization quadrats and compared quadrats on hidden level(P<0.01).There were significant difference on food abundance,herbage coverage,distance to shelter(P<0.01).There were no significant difference on distance to water,arbor coverage,distance to road,distance to human settlement(P>0.05).The typical discriminant functions(composed of 2 ecological factors:arbor coverage and hidden level)can be used to distinguish the utilization quadrats and compared quadrats in autumn.In winter,released Milu prefer the habitat which is closer to water,higher food abundance,higher herbage coverage.There were extremely significant difference between utilization quadrats and compared quadrats on food abundance,herbage coverage,distance to water(P<0.01).There were no significant difference on distance to road,distance human settlement,distance to shelter,hidden level(P>0.05).The typical discriminant functions(composed of 2 ecological factors:herbage coverage and distance to water)can be used to distinguish the utilization quadrats and compared quadrats in winter. |
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