普氏原羚的活动规律与生境选择

ACTIVITY PATTERNS AND HABITAT SELECTION OF THE PRZEWALSKIS GAZELLE (PROCAPRA PRZEWALSKII) IN THE QINGHAI LAKE REGION

普氏原羚生活在沙漠与干旱草原生态交错区（Ｅｃｏｔｏｎｅ）。青海湖畔沙漠中植被盖度较高，沙地沙蒿群落中普氏原羚活动较多，而沙地柏群落中普氏原羚活动较少。普氏原羚在沙地和距离沙地２～３ｋｍ以内的地域内活动，利用起伏沙丘作为隐蔽生境。草原中的芨芨草群落、冷蒿—紫花针茅群落是普氏原羚的主要取食场所。普氏原羚具晨昏型活动规律，在傍晚和清晨取食，其活动避开牛羊的取食时间。普氏原羚常常聚群活动，它们在繁殖期、育幼期和交配期形成大小不同的群体。群体的类型包括同性群、混合群和单一个体群。非繁殖季节普氏原羚雌雄分群活动。目前在人为活动影响下，普氏原羚很难进行季节性迁移。

Przewalskis gazelle is endemic to China, now the species is only found in the Qinghai lake region, where vast desert develops. The Przewalskis gazelle takes desert as a refuge. Whenever it is disturbed, the gazelle flee into the desert. It also rests and ruminates in the sand hills. The gazelle had two major feeding bouts, one in the early morning and another in the late afternoon. The gazelles adopted such a activity to avoid the interference of livestocks grazing in the its feeding habitat during the day time. Since 1994, most of the grasslands and meadow in the Qinghai lake region have been fenced, consequently little room is left for the gazelle. The gazelles are now hanging on in the ecotone between desert and grassland. There are nine major vegetation types in the Qinghai lake region: Achnatherum splendens Community, which occupies the terrain. In the plant community, there are Leymus secalinus, Agropryron cristatum, Carex stenophylla, which are all grazed by the Przewalskis gazelle. However, the gazelle eat little Achnatherum splendens due to its high fiber content in summer, but in winter when available foods are scarce, Achnatherum splendens turned out to be major food resource for the gazelles. Stipa purpursa community is distributed on the plain region 3 300～3 400 m above sea leave, within the community plant coverage is about 50%～70%,other plants in the community include Poa pratensis, Carex stenophylla, Koeleria cristafa. Microscopy of the fecal samples of the Przewalskis gazelle found in the community indicated that the gazelle ate Stipa purpursa, Poa pratensis , Carex stenophylla and Koeleria cristafa . Female gazelle and lambs spent much of their daily time in the plant community, whereas the male gazelles were seldom found in the habitat. Artemisia frigida Stipa purpursa community is developed around the sand hills, vegetation coverage is about 30%, Stipa purpursa, Orinus kokonorica and Carex stenophylla are also found in the plant community, the Przewalskis gazelle selected the Artemisia friida and Carex stenophylla in the habitat. Ephedra intermedia community is also distributed around the sand hills, with plant coverage of about 50%～60%. The grassland is overgrazed by livestock in winter and early spring, therefore many poisonous plants now grow in the plant community. However, the Przewalskis gazelle use the grassland as a feeding ground in summer when the livestock moved to its summer rangelands. Sabina vulgaris shrub and Sabina vulgaris communities are the two major desert vegetations in the region. The plant coverage in the former was 30%～50% with the shrub about 30～50 cm tall. The Przewalskis gazelle mainly graze in the margins of the desert shrubs. We discovered many wolf foot prints followed the hoof prints of gazelle in the shrubs. Sabina vulgaris Community is the largest vegetation type in the desert. Plant coverage was about 25%～45% in the plant community. The Przewalskis gazelle browsed the tip of the Sabina vulgaris . Other frequently found plant species in the community are Leymus secalinus, Calamagrostis phragmites, Agropryron cristatum, Astrgalus tanguticus which all are grazed by the gazelle. Suaeda salsa Polygonum sibircum community in the sand land emerged after the lake water decreased, there are only few plant species in the community. However, the Przewalskis gazelle feed on Suaeda salsa . The information about habitat selection, feeding habit and activity pattern of the Przewalskis gazelle shed lights on its in situ and ex situ conservation.