Social stress and reproductive success in the female Syrian hamster: Endocrine and behavioral correlates

PHYSIOLOGY & BEHAVIOR

卷:104

Article

Chelini, Marie Odile Monier¹  Palme, Rupert²  Otta, Emma¹ 

[1] Univ Sao Paulo, Dept Expt Psychol, Inst Psychol, BR-05508030 Sao Paulo, Brazil

[2] Univ Vet Med, Dept Biomed Sci Biochem, A-1210 Vienna, Austria

关键词: Hamster;    Social stress;    Reproductive success;    Sociobiology;    Cortisol;    Estrogens;    Progesterone;    Fecal metabolites;    Non-invasive monitoring;    Endocrinology;   

DOI  :  10.1016/j.physbeh.2011.06.006

来源: Elsevier

【 摘 要 】

In many mammal species, reproduction is not shared equally among the members of a social unit. Even though reproductive skew seems unlikely in females of solitary species, this phenomenon could result from environmental factors. Although solitary in the wild, captive Syrian hamsters (Mesocricetus auratus) are generally housed in groups. We investigated whether social stress produces some degree of reproductive skew in this solitary species and whether female reproductive success varies as a function of social rank. To assess the physiological relationship between social stress and fertility, we monitored reproductive hormones and glucocorticoids of solitary and pair-housed females during pregnancy by means of recently established non-invasive methods for measuring hormone metabolites in the feces. The patterns of fecal progesterone, estrogen and glucocorticoid metabolites were similar to those found in blood and reported in the literature for pregnant hamsters. As expected, dominant females had higher breeding success than subordinate females. However the rate of reproductive failure was also very high among the singly housed females of our control group. The number of pups per litter, the average sex-ratio in each group, and the mean weight of pups did not differ significantly among groups. Glucocorticoid concentrations were unaffected by housing and social rank and the few differences between the endocrine profiles of singly- and pair-housed females are not sufficient to explain the observed difference in breeding success. It is likely that social isolation impairs reproduction in the same manner as subordination. Our findings suggest that social isolation of animals accustomed to group living was equally as disturbing as cohabitation with an unknown conspecific. (C) 2011 Elsevier Inc. All rights reserved.

【 授权许可】

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