藏羚羊雌性种群的迁徙行为和产仔行为(英文)

Migratory and calving behavior of Tibetan antelope population

2005年6～7月,我们在新疆昆仑山西部的一处藏羚羊繁殖地,对一个雌性藏羚羊的迁徙种群进行了研究。整个调查区域的海拔是4500～5000m,植被覆盖率小于5%,主要植被是垫状驼绒藜(Ceratoidescompacta)。根据研究结果,我们估计在本产仔季节,共有4000～4500头雌性藏羚羊迁徙聚集到一个1200km2的区域内,集中产仔地面积约为350km2。产仔的高峰期是在6月18日～7月7日,其间只有40%的成年雌性产仔,这可能和2004年冬西藏阿鲁盆地的降雪量较大导致藏羚羊在交配期和怀孕期身体条件较弱有关。这个区域的雌性藏羚羊迁徙自西藏的西部,在5月下旬至6月上旬之间到达该区域,然后在7月上旬开始返回。研究区域内的狼、赤狐和大型猛禽是主要的捕食者,但是出现的频次很少。研究区域内大部分藏羚羊成体和幼仔的死亡和天敌捕食没有关系。我们对藏羚羊主要采食的植物的营养成分进行分析,没有发现这个区域和其南部其他区域的差异,所以食物可能不是藏羚羊迁徙的主要原因。躲避捕食者、躲避传播寄生虫病的昆虫干扰、或者是避开牧民和家畜,这些因素都有可能导致藏羚羊雌性迁徙到这个区域产仔。基于本次研究,我们建议新疆和田地区能够对这个产仔地进行严格保护,禁止产仔期的人类干扰,同时有必要考虑建立一个大型保护区,或者和相邻保护区联合起来进行管理。

A migratory population of female Tibetan antelope or chiru was studied on its calving ground in the western Kunlun Mountains, Xinjiang in June - July 2005. It was estimated that 4 000 - 4 500 females were in the 1 200 km^2 calving area but most births were concentrated in 350 km^2. The habitat at 4 500 -5 000 m in elevation had vegetation coverage of less than 5%, principally the dwarf shrub Ceratoides compacta. Young were born 18 June -7 July with a peak 24 June -3 July. Only about 40% of adult females had young, a low fecundity possibly the result of heavy winter snows leading to poor physical condition. Wolf, red fox, and birds of prey killed a few chiru but predators were scarce; most mortality was unrelated to predation. Females arrived at the calving grounds in late May and early June from the west of Tibet, and by early July started their return migration. It remains unclear why chiru migrate to that site. Analysis of chiru food plants showed no marked difference in nutritive values at this season between the calving grounds and the southern range. Escape from predators, parasitic insects, and people with their livestock may all have a role. Based on the study, we suggest that the main calving ground requires strict protection from disturbance, and a large reserve in the region needs to be established.