根田鼠的熟悉性及其自然动情下的配偶选择

报道了在室内雌鼠自然动情条件下根田鼠两性个体配偶选择的3种熟悉性效应的5组实验结果,包括雌性对熟悉和陌生雄鼠、配偶和陌生雄鼠、配偶和熟悉雄鼠的择偶行为实验 , 雄性对熟悉和陌生雌鼠、配偶和陌生雌鼠的择偶行为实验。在实验前, 将1对性成熟的雌雄鼠 (非亲缘关系) 每天关养8 h 共8 d 建立熟悉性; 配对雌雄鼠至少生育1胎则为配偶关系。在 Y 形迷宫内的30 min 实验中, 两个被选择鼠分别以项链拴在横跨选择箱顶端中央的一根铁丝上, 限制它们在各自箱内活动; 而允许异性选择鼠从中立箱自由进入两个选择箱。记录选择鼠对异性被选择鼠的访问、社会探究、攻击、交配和友好行为的频次和时间。经Wilcoxon 关联样本 T 检验发现, 除交配行为不显著外, 雌性根田鼠均选择熟悉性较高的雄鼠; 而雄鼠不具这种选择性。该结果提示雌雄根田鼠的不同择偶行为也许就是反映该种婚配制度特征的直接行为过程。因此, 在择偶行为中, 雌性根田鼠表现的单配性倾向和雄鼠的多配性倾向, 只能以其婚配制度为一雄多雌制的假设来解释。我们的实验还说明在多配制田鼠中, 一雄多雌制与混交制在雌鼠择偶行为上是不同的, 而与单配制的相似或相近, 故简单地比较多配制与单配制则不能反映田鼠亚科动物婚配制度的多样性。

FAMILIARITY AND MATE CHOICES OF FEMALE AND MALE ROOT VOLES (MICROTUS OECONOMUS) IN FEMALE NATURAL ESTRUS

Many behavioral experiments compared monogamous species with polygamous one in microtine rodents show that the mating systems are associated with mate choice among individuals, and a major component determining nature of the sexual selection is familiarity between males and females. The long- and short-term effects of familiarity on both sexes mate choices of root voles (Microtus oeconomus) was examined by three kinds of laboratory experiments. They were mate preference of the experimental root voles for the familiar versus the unfamiliar, the partner versus the unfamiliar and the partner versus the familiar stimulus ones. Familiarity was established by housing a male with an unrelated female in a plastic breeding cage for 8 h each day until they were found to display sexual behaviors. Partnership referred as the relationship between a pair of male and female having bred at least one litter of offspring. During a 30 min trial, two stimulus voles were tethered in two choice chambers of a Y-shaped maze respectively, while the experimental vole was allowed to enter either of the two choice chambers from the central arena. The experimental vole was scored for duration and frequency of visit, social-investigation, copulatory behavior, aggression and amiability with each stimulus vole. Behavioral comparison between the two stimulus voles was achieved by a Wilcoxon matched-pairs test. The results showed that the females preferred the familiar rather than unfamiliar males, the partner rather than unfamiliar males, the partner rather than familiar males in the social behaviors except for copulatory behavior with no significant level. However, the males made no a preference for the familiar versus the novel females, nor the partner versus the novel females. These data suggested that female preference for familiar males and males having no mate choice between familiar and strange females may be proximate behavioral processes underlying traits in mating system of root voles. Thus, female mating monogamously and male non-monogamously can be explained by the hypothesis that the mating system could be polygynous in root voles.