大鸨的巢位选择研究

20 0 0年和 2 0 0 1年的 4～ 7月连续两年 ,在内蒙古自治区科尔沁右翼前旗东南部草原上采用野外直接观测和样方法对繁殖期大鸨 (Otistarda)的巢位选择进行了研究 .结果表明 ,大鸨是一种营地面松散型群巢的大型鸟类 ,最近巢间距为 9m .大鸨在繁殖期对巢位具有明显的选择性 :首先表现在景观尺度上的选择 ,大鸨巢多筑在海拔 190～ 2 30m的草原岗坡的坡腰上 ,以偏南向的朝阳缓坡的坡腰上为多 ,最大坡度不超过 8° ,而且巢均筑在距车道不远的地方 ;其次表现在植被结构上的选择 ,大鸨倾向于选择枯草较厚、植被密度较高且多数植物高度在 15～ 35cm的地方营巢 ,但植被密度过高处却并不选择 .

On nest-site selection of Otic tarda

During April to July in 2000 and 2001,the nest site selection of Otis tarda was studied by direct observation and sampling method in the southeast grassland of Keyouqianqi in Inner Mongolia.The results showed that Otis tarda was one kind of big sized bird built nests on the ground in sparse cluster, and the smallest distance between nests was 9m. Otis tarda had a significant tendency in nest site selection.Firstly,this tendency was represented under the scale of landscape.Most nests of Otis tarda were built on the mid hill of grassland,the elevation range was from 190m to 230m,most nests built on the slopes faced to sun, and the biggest gradient was not more than 8 degree.Moreover,the nests were near to roads.Secondly, Otis tarda selected its nest site according to vegetation structure.It tended to select nest site with thick hay,high vegetation density and grass height from 15cm to 35cm,but would not select the place with over high vegetation density no nest.