科创中国

Age of maturation and behavioral tactics in male yellow ground squirrel Spermophilus fulvus during mating season

原文链接：万方

• 作者：

  Nina A. VASILIEVA Ekaterina V. PAVLOVA Sergey V. NAIDENKO Andrey V.TCHABOVSKY

• 摘要：

  Life-history theory predicts that in hibemators age of maturation is related positively to body size and negatively to the duration of active season aboveground. Yellow souslik is a large-sized ground squirrel with long hibernation, which suggests late maturation. We used four-year field observations of marked individuals to determine the age of maturation in males through analysis of age-dependent variation in body size, mass, androgen status, timing of spring emergence, ranging patterns and social behavior during the mating season. Yearling males were smaller, lighter, had lower level of fecal testosterone, emerged later and had smaller home ranges than older males. Social activity and the number of females encountered did not differ between age classes. After the second hibernation none of the studied parameters varied with age. Cluster analysis revealed two behavioral tactics: "active" males (adults only) emerged earlier, ranged more widely, initiated more contacts, encountered more females and were heavier than "passive" males (both yearling and adult). Thus, males of S. fulvus reached adult size and matured after two hibernations, which is relatively fast for such a big species with short active period. Indirect evidence for copulations and high variation among yearlings in all parameters suggest that some of them might successfully compete with adults. Active tactic of wandering and searching for females is energetically costly, and probably only adult males in good physical condition can afford it, whereas passive tactic of residing is energy saving and good for adults in poor condition and for yearlings that are continuing to grow.

• 关键词：

  成熟年龄 行为策略 男性 交配 季节 黄鼠 黄色 车身尺寸

• 作者单位：

  A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, 33, Leninsky pr., Moscow, 119071, Russia

• 基金项目：

  Acknowledgements We are grateful to S.A. Shilova who encouraged and supported the study. We thank L.E. Savinetskaya, V.S. Popov, N.S. Vasiliev, I.A. Volodin, E.V. Volodina, V.A. Matrosova, A.A. Kochetkova and other members of our field team, and thank Dr. Michael Birman for polishing the revised paper. Comments and suggestions of two anonymous reviewers to a previous version of this manuscript were very helpful. The study was financially supported by the Russian Foundation for Basic Research (grants10-04-01304a and12-04-31279).

• 来源期刊：

  动物学报(英文版)

• 年，卷(期)：

  2014006