高密度种群的社会条件对大沙鼠幼年雄鼠形态生理特征的影响:一个实例研究

在非繁殖期高密度大沙鼠(RhombomysopimusLicht)种群中,我们研究了胁迫以及幼年雄鼠的性激素浓度、腹中腺大小和体重对社群中成体(≥1年龄)存在的依赖性。用无损伤放射免疫方法,测定了于1999年秋天在野外采集的幼年雄鼠粪便样品的皮质酮和睾酮。有成体社群中的个体大于无成体社群的个体。因此,成体对幼体的影响不能独立于社群大小本身。成体的存在促进粪便睾酮的浓度和抑制了幼年雄鼠的性成熟(由雄激素依赖的较小的腹中腺来估计),但是同时促进了其生长。因此,自然存在的社群环境能影响幼年雄鼠的形态生理特征发育。

Social influences on the morpho-physiological characteristics of young males in groups of great gerbils Rhombomys opimus in a high density population: a case study

In a non-breeding, high density population of great gerbil (Rhombomys opimus Licht) (Bukhara region, Uzbekistan) we studied the dependence of stress and sex hormone concentrations, size of the mid-ventral gland and body mass of young males on presence of adult gerbils (≥1 year old) in social groups. Corticosterone and testosterone in fecal samples collected in the field from young males in fall 1999 were analyzed by non-invasive radioimmunoassay. Gerbil groups with adults were larger in size than groups without adults, so the effect of adults on juveniles can not be considered independently from the group size effect per se. Presence of adults positively affected concentration of fecal corticosterone and suppressed maturation of juvenile males estimated by the smaller size of the mid-ventral gland as an androgen-dependent organ, but at the same time accelerated their growth. Thus a naturally occurring social environment can influence development of morpho-physiological characteristics of young malesActa Zoologica Sinica 52(3):454-461,2006].