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长爪沙鼠种群繁殖的季节性特征

刘伟 宛新荣 钟文勤 王建青   

  1. 中国科学院动物研究所
  • 出版日期:2013-02-27 发布日期:2013-02-20

Characteristics of seasonal reproduction in Mongolian gerbils (Meriones unguiculatus)

LIU Wei,WAN Xinrong,ZHONG Wenqin,WANG Jianqing   

  • Online:2013-02-27 Published:2013-02-20

摘要: 长爪沙鼠是分布于我国北方典型和荒漠草原及农牧交错区的优势鼠种之一。2000 年10 月至2004 年10 月通过标志重捕法研究了栖息于内蒙古农牧交错区草地生境的种群动态。对其不同季节出生群性成熟特征和种群性成熟比率、繁殖个体比例、个体月补充率等繁殖参数的季节特征研究显示:冬季和春季出生的个体性成熟较夏季出生的个体快,尤雌鼠表现突出,其3 个季节出生群的性成熟时间分别为4. 6 ± 0.2、4. 4 ± 0.8 和7.7 ± 0.4月龄。种群性成熟比率、繁殖个体比例和个体补充率月间差异显著,季节消长明显,即春季最高,秋季(9 ~10月间)最低。结果还显示,种群性成熟比率与气温和降水负相关。长爪沙鼠喜栖于植被稀疏、低矮的干燥沙质土壤环境。从初春到夏末,随降水和气温增加其栖息生境的植被由低矮稀疏变得高而稠密,土壤湿度和粘性亦随之提高,地面种子库因发芽贮量减少,适宜生境的减少可能加剧了社群竞争,抑制了种群的繁殖表现。长爪沙鼠种群繁殖的季节变化反映了其生活史对策中适应高纬度气候和食物的季节波动的重要特征。

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