藏羚主要分布在青藏高原,雌性有季节性的生殖迁徙行为.产仔前,分布在各地的雌性藏羚沿着比较固定的路线向青藏高原西北部可可西里的太阳湖、卓乃湖、阿尔金山保护区的慕孜塔格峰等产羔地迁徙,产羔后一段时间又返回原栖息地.对这种特殊的迁徙现象,已有一些假说用来解释,但都没有得到普遍认可.青藏高原由于其海拔高,常年温度低,在藏羚分布区降水主要以固态形式为主,并且青藏高原降水量由东南部向西北部递减,结合青藏高原地质历史时期植被演变的特点和藏羚迁徙的方向,本文提出了一个新假设,以此来解释藏羚迁徙的原因.我们的假设是:藏羚迁往产羔地产羔是为了躲避固态降水相对丰富的地区,以保证新生羚羊有高的存活率;藏羚迁往的产羔地曾是它们的故乡.笔者主要分析了提出这个假设的根据.
Female Tibetan antelope(Pantholops hodgsoni),migrate seasonally,and follow specific routes on the Qinghai-Tibet Plateau during the course of a migration.Female antelopes leave their winter ranges with plentiful food resource and travel to relatively barren breeding grounds for breeding,such as Zhuonai Lake,Taiyang Lake in Kekexili Nature Reserve and Muztag Feng in Arjin Shan Nature Reserve;and after breeding,they return to their winter ranges.It remains unclear why they migrate to breeding grounds for breeding.Although a variety of explanations have been offered,most of them fail to give sufficient illustration and proof.Here we propose a hypothesis for their migration,taking into consideration of both the snowfall cline and the geological vegetation evolution of its habitats——Qinghai-Tibet Plateau,where snowfall makes main type of precipitation owing to its high elevation and low temperature.In our hypothesis,the breeding grounds are possible the original habits of Tibetan antelope according to the geological vegetation evolution of Qinghai-Tibet plateau.Because snowfall decreases gradually from southeast to northwest within the Qinghai-Tibet plateau,we hypothesize that female Tibetan antelope migrate from winter ranges(in the southeast) to breeding grounds(in the northwest) to avoid relatively high snowfall.We hypothesize that the climatic conditions in breeding grounds favor survival of newborns.