蜂桶寨自然保护区中华姬鼠及社鼠肥满度的年龄和季节变化

Comparison of Relative Fatness for Apodemus draco and Niviventer confucianus across Age Classes and Seasons in Fengtongzhai Nature Reserve,China

肥满度被广泛用于动物生长状况与环境、生存、繁殖等方面的研究。为揭示横断山脉森林环境中中华姬鼠（Apodemus draco）和社鼠（Niviventer confucianus）肥满度的变化规律及影响原因，我们于2008年4～11月对四川省蜂桶寨国家级自然保护区内中华姬鼠和社鼠肥满度在各年龄组及不同季节中的变化进行了研究。结果显示，中华姬鼠肥满度在各年龄组间的差异显著，其变化趋势为老年组〉成年组〉亚成年组〉幼年组；亚成年组及老年组肥满度在各季节间无显著差异，而在成年组则差异明显，以春季中最高。社鼠肥满度在各年龄组间无显著性差异；亚成年组肥满度在各季节间差异显著，在夏秋季中最低，同时成年组及老年组肥满度在季节间无显著差异。中华姬鼠和社鼠亚成年组、成年组及老年组肥满度与海拔无显著的线性关系。分析认为，中华姬鼠老年组个体可能在应对外界环境方面要强于幼年个体而具有最高的肥满度，成年个体肥满度的季节变化可能受食物资源季节差异和繁殖能量需求的影响；社鼠成年及老年个体能通过相应的季节性调节维持肥满度的稳定，而亚成年个体在调节方面较弱，故其肥满度在夏秋季最低。

Relative fatness index is widely used to uncover the relationship between environment factors and animal individual＇ s survival and reproduction. Changes in relative fatness of Apodemus draco and Niviventer confucianus across age classes and seasons were investigated from April to December 2008 in Fengtongzhai Nature Reserve, Sichuan province, China. The results showed that differences of the relative fatness between males and females for A. draco across age groups were not significant. However, it was significantly different among seasons for their relative fatness, and changed from the highest in olds, higher in adults, lower in subadults and then the lowest in juveniles. The relative fatness in sub-adults was not significantly different among seasons, contrary for adults which was highest in spring while lower in summer-autumn and winter. For N. confucianus, its fatness was not significantly different across age groups. However, for N. confucianus sub- adults, their relative fatness was significantly different among seasons. The relative fatness for the two species was not significantly correlated with elevations. Higher relative fatness of A. draco in old classes than those in juvenile classes probably implied that the old individual possessed high ability to adapted to changing environment conditions. Meanwhile, the relative fatness of seasonal changes in adults may be affected by availability of food resources and breeding energy demand across seasons. Adult and old individuals of N. confucianus can maintain stable relative fatness through some measures. However, regulating ability of N. confucianus sub-aduh ones is relative weaker, which results in the lowest fatness in summer-autumn.