贺兰山岩羊种群结构的季节性变化  

The Seasonal Change of Blue Sheep Population Structure in Helanshan Mountains

作　　者：余玉群[1] 郭松涛[1] 白庆生 李志刚 胡天华 吕海军 

机构地区：[1]陕西省科学院动物研究所,西安710032 [2]宁夏贺兰山国家级自然保护区,银川750001

出　　处：《兽类学报》2004年第3期200-204,共5页Acta Theriologica Sinica

基　　金：国家林业局"全国盘羊资源专项调查"项目

摘　　要：2001年3月至2002年2月,每月定期在固定的样线上,采用样线法对贺兰山3929只岩羊种群结构进行调查。小群体是贺兰山岩羊种群的基本特征,全年群平均数为5 5只,独羊全年存在,以雄性成体为主,在雌性群中,母仔群全年稳定,占雌性群的44 0%。岩羊雌性群群体大小平均3 5只,雄性群群体平均4 5只,混合群群体平均8 0只;全年雌性多于雄性,雌性群小于雄性群。群体表现为雌性群群体小,群体数量多;混合群体大,群体数量少。混合群群体大小范围离散,雄性群次之,雌性群群体范围变化最小。全年雌幼比为100∶48。雌雄性比全年100∶71,其中,2～6月份,雌雄性比为100∶130～155;7～12月份,雌雄性比为100∶43～68。另外,文中还指出3 5～8 5龄雄羊占63 9%,1 5～3 5龄和超过8 5龄老年雄性岩羊所占的百分率明显较少。From March 2001 to February 2002, we observed 690 groups with 3 929 blue sheep (Pseudois nayaur), including 129 solitary individuals, in Helanshan Mountains at the northern extent of the species'range. Each month, we surveyed blue sheep in 8 sample lines (3-4 km each) within 3 ravines. The blue sheep population had been protected for 20 years, and we noted that animals were easier to be observed than in 1984. Blue sheep primarily used low hills with sparse grassland at elevations of (1 400)-(1　800 m).Population density was estimated at 8.3 individuals/km^2, higher than that of blue sheep on the Qinghai-Tibet Plateau. The solitary consisted of 60% males and 40% females, which appeared throughout the year except December. The mean year-round herd size was 5.5, but varied with season. This group size was smaller than the blue sheep distribution within the Qinghai-Tibet Plateau and neighboring ranges, we attribute to topographic differences between the Helanshan and the Qinghai-Tibet Plateau. The average size of male herd was 4.5, while female herd was 3.5. With such male herd had a higher average within its range than female herd in Helanshan because female-infant group occured with high frequency. The mean size of mixed-sex groups was 8.0. The year-round mean sex ratio (F∶M) was 100∶71; however, during February-June varied from 100∶130 to 100∶155 (i.e., favored males),whereas during July-December varied from 100∶43 to 100∶68 (favored females). The year-round adult female∶ young ratio was (100∶48). Among males, age groups 3.5-8.5 years old constituted 63.9%, whereas 1.5-3.5 year old and over 8.5 year old rams were observed significantly less often.

关 键 词：贺兰山 岩羊 种群结构 季节性变化 群体组成 

分 类 号：Q959.842[生物学—动物学] Q958.1