不同密度下和不同发情期时段中雄性麋鹿的繁殖计策

Rutting tactics in Père David’s deer stags under different population densities and during different rut periods

从1998年到2001年,我们研究了密度、发情期与雄性麋鹿繁殖计策的关系。我们选择了江苏大丰麋鹿保护区的两个麋鹿群体和北京麋鹿苑的一个麋鹿群体,观察记录了发情期前期、中期和后期中实验麋鹿种群参数、围栏大小、群体中雄鹿的繁殖计策、群主变更情况、后宫数目以及后宫雌鹿数。尽管不同种群和不同发情期的雄鹿繁殖计策有差异,但是各个群体中雄性麋鹿都有占群、偷袭交配和求偶集会3种繁殖计策。利用因子分析提取了两个主成分:主成分1主要代表实验围栏、麋鹿存栏数和密度等因子的影响,主成分2主要代表发情期时段因子的影响。这两个主成分解释了全部因素效应的90.72%。用Spearman相关分析发现,占群计策与主成分2呈极显著负相关,求偶集会计策与主成分1呈显著正相关,最大后宫雌鹿个体数与主成分1极显著正相关,而偷袭交配计策和后宫数目与主成分1和2均无显著相关。据此推测,占群和求偶集会繁殖计策分别受密度和发情期时段的影响,而偷袭交配行为对密度和发情期时段不敏感。我们还探讨了麋鹿发情行为计策的环境适应性,从行为学角度为麋鹿保护提供了新思路。

From 1998 to 2001, we investigated the relationship between population density, rut tactics and rut phases of Père David＇s deer. We chose three groups of Père David＇s deer as experimental animals： two groups from the Père David deer population in the Dafeng Père David Deer Nature Reserve, Jiangsu Province and one group from the Père David deer population in the Beijing Père David Deer Park, Beijing. We recorded population parameters and closure area, reproductive tactics, the events of changing harem master, the numbers and size of harems during the prophase, metaphase and anaphase of the rutting season. Three rut tactics - harem holding, sneak mating and lekking - were all recorded in these populations, though there were variations in the rut tactics among the three populations during the three phases. With Factor Analysis, we extracted two main components associated with rutting tactics： component 1 mainly represented the observation site, the number of deer and the density of deer, whereas component 2 mainly represented the phases of the rutting season. Spearman correlations showed that： （1） “sneak” tactics occurred during the whole rut season, while harem holding and lekking tactics only occurred during certain phases of the rut; （2） as population density increased, the stags tended to adopt lekking tactics. Thus, we conclude that “holding a harem” is the main rut tactic among Père David＇s deer stags, however, stags also adopt different rutting tactics related to the phases of rut and the density of the population. We discuss the significance of rut behavioral adaptation toenvironment in Père David＇s deer, and put forward ideas about conservation of Père David＇s deer.