Spatio Temporal Variability Of Relative Fatness And Sex Ratio Of Microtus Fortis In Dongting Lake

Relative fatness is one of the most commonly physiological indexes to measure the adaptation of animals to the ecological environment.The sex ratio of population is an important characteristic of rodent population.In order to further understand the community characteristics of small mammals and factors that affect the relative fatness and sex ratio of them,the characteristics of various populations of small mammals were analyzed,based on censuses of small mammal communities in Dongting Lake for a period of 14 years.Particularly with regard to Microtus fortis,it was analyzed that the population density in different habitats and their population fluctuation,and the effect of meteorological factors and NDVI on the relative fatness and sex ratio.The result was as follows: 1.There were some seasonal differences in the species composition according captured small mammals among different habitat;Microtus fortis had a relatively high proportion in lake beach habitat.2.For beach habitat,there was a significant difference in population density of Microtus fortis among different seasons.And specifically,the density was highest in summer,while it was lowest in autumn and winter.3.There was a significant difference in relative fatness of Microtus fortis among different seasons in two kinds of beaches which were covered mainly by Phragmites spp.or by Carex +Phragmites +Populus spp.In spring and winter,there was a significant difference in relative fatness among different habitats.There was a significant positive correlation between female relative fatness and seasonal average rainfall,NDVI of farmland habitat,respectively.And there was no significant correlation between male relative fatness and seasonal average rainfall,air temperature,NDVI of habitat,respectively.4.The seasonal variation of sex ratio of Microtus fortis was not significant in all habitats,except for significant difference in spring among different habitats.5.There was no significant correlation between sex ratio of Microtus fortis with seasonal average rainfall,air temperature,NDVI of habitat,respectively.