Wildlife Conservation Research Unit, Department of Zoology, University of Oxford, The Recanati-Kaplan Centre, Tubney House, Tubney OX13 5QL, UK; Ethiopian Wolf Conservation Programme, PO Box 215, Robe, Bale, Ethiopia; Institute for Breeding Rare and Endangered African Mammals (IBREAM), Mammal Research Institute, University of Pretoria, Lynnwood Road, Pretoria 0028, South Africa.
Physiol Behav. 2013 Oct 2;122:39-45. doi: 10.1016/j.physbeh.2013.08.016. Epub 2013 Aug 29.
Ethiopian wolves, Canis simensis, differ from other cooperatively breeding canids in that they combine intense sociality with solitary foraging, making them a suitable species in which to study the physiology of cooperative breeding. The reproductive physiology of twenty wild female Ethiopian wolves (eleven dominant and nine subordinate) in Ethiopia's Bale Mountains National Park was studied non-invasively through the extraction and assaying of estradiol, progesterone and glucocorticoids in collected fecal samples using enzyme and radioimmunoassays. All dominant females showed increased estradiol concentrations and/or mating behavior during the annual mating season. In contrast, none of the subordinate females showed increased estradiol concentrations or mating behavior during the mating season. However, two subordinate females came into estrus outside of the mating season. Both dominant and subordinate females had higher average progesterone concentrations during the dominant female's pregnancy than at other times of the year, and two subordinate females allosuckled the dominant female's pups. No statistically significant differences in glucocorticoid concentrations were found between dominant and subordinate females. These results suggest that subordinate females are reproductively suppressed during the annual mating season, but may ovulate outside of the mating season and become pseudopregnant. No evidence was found to suggest that reproductive suppression in subordinate females was regulated through aggressive behaviors, and no relationship was found between fecal glucocorticoids and dominance status.
埃塞俄比亚狼（Canis simensis）与其他具有合作繁殖行为的犬科动物不同，它们将强烈的社会性与独居觅食结合在一起，使它们成为研究合作繁殖生理的合适物种。本研究通过采集埃塞俄比亚 Bale 山国家公园的 20 只野生雌性埃塞俄比亚狼（11 只优势个体和 9 只从属个体）的粪便样本，运用酶联免疫吸附测定法和放射免疫测定法，对其粪便中的雌二醇、孕酮和皮质酮进行提取和检测，从而对其非侵入性的生殖生理学进行了研究。所有优势个体在每年的繁殖季节都表现出雌二醇浓度升高和/或交配行为。相比之下，从属个体在繁殖季节都没有表现出雌二醇浓度升高或交配行为。然而，有两只从属个体在繁殖季节之外进入发情期。在优势个体怀孕期间，优势个体和从属个体的平均孕酮浓度都高于一年中的其他时间，并且有两只从属个体为优势个体的幼崽提供了代乳行为。在优势个体和从属个体之间没有发现皮质酮浓度的统计学显著差异。这些结果表明，从属个体在每年的繁殖季节中受到生殖抑制，但可能在繁殖季节之外排卵并出现假性怀孕。没有证据表明从属个体的生殖抑制是通过攻击性行为来调节的，也没有发现粪便皮质酮与优势地位之间存在关系。
