Shimozuru Michito, Kikusui Takefumi, Takeuchi Yukari, Mori Yuji
Laboratory of Veterinary Ethology, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Physiol Behav. 2006 Dec 30;89(5):644-9. doi: 10.1016/j.physbeh.2006.08.001. Epub 2006 Sep 7.
Social hierarchy plays an important role in the lives of gregarious species. We investigated how social hierarchy between male Mongolian gerbils (Meriones unguiculatus) housed together before sexual maturity affected their scent-marking behavior, endocrine status and physical traits as adults. The social rank between paired males was assessed based on sexual activity in adulthood at 18 and 20 weeks of age. In most cases, the male that showed higher sexual activity at 18 weeks also exhibited greater sexual performance at 20 weeks, suggesting a precedence relationship between paired males regarding reproductive opportunity. Sexually active males scent-marked more often than their cage mate, particularly after a sexual experience. No significant differences in physical traits (e.g., the weight of the ventral gland, testes and adrenal glands) or endocrine status (e.g., fecal testosterone and corticosterone levels) were found between the two males. These findings suggest that social rank between familiar males formed during cohabitation, and rank was closely correlated with scent-marking activity, but not with endocrine status.
社会等级制度在群居物种的生活中起着重要作用。我们研究了性成熟前一起饲养的雄性蒙古沙鼠（长爪沙鼠）之间的社会等级制度如何影响它们成年后的气味标记行为、内分泌状态和身体特征。根据18周和20周龄成年期的性活动来评估配对雄性之间的社会等级。在大多数情况下，18周时性活动较高的雄性在20周时也表现出更强的性能力，这表明配对雄性在生殖机会方面存在先后顺序关系。性活跃的雄性比其笼伴更频繁地进行气味标记，尤其是在有性经历之后。在这两只雄性之间，未发现身体特征（如腹腺、睾丸和肾上腺的重量）或内分泌状态（如粪便睾酮和皮质酮水平）有显著差异。这些发现表明，同居期间熟悉的雄性之间形成了社会等级，且等级与气味标记活动密切相关，但与内分泌状态无关。
