关键词: 长爪沙鼠, 标志重捕, 季节出生群, 性成熟率, 生活史对策

Abstract: The Mongolian gerbil (Meriones unguiculatus)widely distributed in semi-arid,typical steppes,and desert grasslands in the north of China and is one of dominate rodents. We studied reproduction and population dynamics of Mongolian gerbils under semi-natural conditions in south-central Inner Mongolia using monthly capture-recapture methods from
October 2000 to 2004. In this study,we analyzed seasonal changes in reproductive parameters such as cohort-specific age of sexual maturity,proportion of sexually mature gerbils, proportion of reproducing gerbils,and the ratio of recruits to reproductive females. Mongolian gerbils displayed significant seasonal fluctuations in reproductive performance. We found that age at the sexual maturity of females born in winter (4.6 ± 0. 2 month)and spring (4.4 ±0.8 month)was younger than that of gerbils born in summer (7.7 ± 0.4 month). Reproduction primarily occurred in spring and ceased in autumn. We also found that increased temperature and precipitation from spring to summer negatively affected maturation proportion. Mongolian gerbils prefer habitats with short,sparse vegetation and dry,loose,sandy soil. Increases in temperature and rainfall enhance vegetation growth;consequently, tall,dense,moist vegetation might reduce the suitability of habitats and retard reproduction of Mongolian gerbils. Therefore,pronounced seasonal dynamics of reproduction may reflect a vital feature of life-history strategies of Mongolian gerbils:adaption to seasonal changes in climate and food abundance in northern high latitudes.

Key words: Capture-mark-recapture method, Life-history strategy, Mongolian gerbil (Meriones unguiculatus ), Sexual maturation proportion, Seasonal-specific cohort