雄性弯角长角羚和普通大羚羊激素分泌模式与社会等级和季节的关系

为了确定羚羊类固醇激素分泌模式与行为和社群等级的关系,我们检测了成年雄性弯角长角羚(n=15)和普通大羚羊(n=11)的粪样皮质酮和睾酮浓度.采用随意取样和目标取样法记录了共650 h的行为.结果发现,两种羚羊的睾酮水平在雌性的发情时段里都是最高的.两种羚羊皮质激素水平有季节性变化,表现为雨季皮质酮水平高于干旱季节.优势胁迫作用明显存在于普通大羚羊,而在弯角长角羚不明显.没有证据表明从属个体压力的存在,一只弯角长角羚曾经是优势个体,但是后来有两年不是优势个体,与其他雄羚相比,这只雄羚在雌性发情期的睾酮和皮质酮水平有3个交迭出现的峰值.

Hormonal patterns associated with social rank and season in male oryxes Oryx dammah and elands Taurotragus oryx

In order to determine if steroidal hormone concentrations could be related to behavior and social rank in antelopes, fecal concentrations of corticosterone and testosterone were determined in the adult males of two species of antelope, elands Taurotragus oryx (n=15) and oryxes Oryx dammah (n=11). Ad libitum and focal behaviors were recorded for a total of 650 hours. It was found that in both species testosterone was highest at the time of estrus in the females. Both species demonstrated seasonal variation, as corticosterone was higher in the rainy season than in the dry season. Dominance stress was apparent in dominant male elands but not oryxes. While there was no evidence of subordinate stress, one oryx which had been dominant but then was excluded for two years had three fold higher testosterone and corticosterone than the other males at estrus.