雄性麋鹿的交配机会、社会等级和皮质醇水平

我们在北京麋鹿苑研究了发情期雄性麋鹿的社会行为、社会等级和血清皮质醇水平,并分析了三者间的相互关系。按照雄性麋鹿的行为,将雄性麋鹿分为优势群和从属群。优势群包括群主和挑战者,从属群包括单身汉和被淘汰群主。使用SJ—Ⅰ型事件记录器进行常规行为取样,用放射免疫分析法测定血清皮质醇含量。发现：(1)优势雄鹿的发情行为频次明显高于从属雄鹿;(2)攻击行为的发生频次在两组间无显著差异;(3)血清皮质醇含量在两组间也无显著差异。由此我们认为,发情期雄性麋鹿的社会等级序位影响许多行为的表达,优势雄鹿成功交配的机会比从属雄鹿多。而攻击行为和肾上腺皮质醇的分泌与社群等级无明显相关,可能是麋鹿在圈养状态下的一种适应策略,这将有利于缓解发情期雄鹿的紧张,从而允许更多的能量投放在发情交配上。

Cortisol levels, dominance rank and mating opportunities in Pere David's deer stags

We conducted an experiment in the Beijing Milu Park to study the social behavior of male Pere David's deer,Elaphurus davidianus, and explored the relationship between social position and serum cortisol level. We classified the stags into a dominant group which included the "harem master" and "challenger", and a subordinate group which included "bachelor" and "post-rut master", then monitored behavior of these stags whilst analyzing serum cortisol concentrations in the observed stags. We found that (1) tbe dominant stags displayed rut behaviors more frequently than the subordinate stags, (2) there was no significant difference in aggressive behaviors between the two groups, and (3) although it seemed that serum cortisol concentrations of one harem master was higher than that of one bachelor, we did not find the significant difference of cortisol levels between the two groups. We conclude that social rank affects social behaviors of Pere David's deer stag during rut. Pere David's deer stag maintain reproductive competence in the face of increased physical and psychological stress during rut.