The feeding habitat selection of blue sheep(Pseudois nayaur)was studied by direct observation method in the Helan Mountains,China during winter(from Novembe r to December)and spring(from April to June)from 2003 to 200...The feeding habitat selection of blue sheep(Pseudois nayaur)was studied by direct observation method in the Helan Mountains,China during winter(from Novembe r to December)and spring(from April to June)from 2003 to 2004.We established 25 line transects to collect information on feeding habitats used by blue sheep.Blue sheep in the study area preferred mountain savanna forests,a habitat dominated by Ulmus glaucescens,with medium tree density(<4 individuals/400 m^(2)),moderate tree height(4-6 m),higher shrub density(>5 individuals/100 m^(2)),higher shrub(>1.3 m),higher food abundance(>50 g),moderate distance to human disturbance(<500 m),and mild distance to bare rock(<2 m).Such habitats characterized by 12 ecological factors were preferred as feeding areas by blue sheep during winter.Similar to habitat selection by the species during winter,blue sheep also showed a preference for mountain savanna with tree dominated by Ulmus glaucescens and medium tree density(<4 individuals/400 m^(2))during spring.Nevertheless,blue sheep preferred medium tree height(<6 m),moderate tree density(5-10 individuals/100 m^(2)),medium shrub height(1.3-1.7 m),higher food abundance(>100 g),moderate altitude(<2000 m),moderate distance to water resource(<500 m),and medium hiding cover(50%-75%)during spring.Selection of the feeding habitats by sheep showed a significant difference in vegetation type,landform feature,dominant tree,tree height,shrub density,distance to the nearest shrub,food abundance,slope direc-tion,slope degree,distance to water resource,and hiding cover between winter and spring.Results of principal com-ponents analysis indicated that the first principal component accounted for 24.493%of the total variance among feeding habitat variance during winter,with higher loadings for vegetation type,dominant tree,tree height,distance to the nearest tree,shrub density,shrub height,altitude,distance to water resource,and distance to human disturbance.In spring,the first principal components explained 28.777%of the vari-ance,with higher loadings for vegetation type,distance to the nearest tree,shrub height,distance to the nearest shrub,food abundance,altitude,and distance to human disturbance.展开更多
Group size and composition of blue sheep(Pseudois nayaur)were studied in the Helan Mountains, Ningxia Autonomous Region from November to December 2003.We scanned mountain slopes with binoculars and observed with 20-60...Group size and composition of blue sheep(Pseudois nayaur)were studied in the Helan Mountains, Ningxia Autonomous Region from November to December 2003.We scanned mountain slopes with binoculars and observed with 20-60× spotting-scope. A total of 310 herds of blue sheep and 1 336 individuals were observed during the study period. Blue sheep were frequently seen in small herds of 2 to 8 individuals, which represent 94.8% of total herds observed. Herds consisting of 9 individuals or more represented 5.2%. The largest herd we observed numbered 51 individuals. Mean group size was 4.2 individuals. Blue sheep herds can be divided into three types: male herds (composed solely of males), female herds (consisting of females with or without juveniles of both sexes), and mixed herds (including adult males, females, and subadults).Among the 310 herds, female herds were counted 150 times(48.4%), mixed herds 154 times(49.7%), and male herds 6 times(1.9%). Of 1 336 blue sheep classified by sex and age, adults, subadults and juveniles composed 64.1%,20.8%, and 15.1% respectively. The female:male ratio of adults was 1∶0.73. The ratio of adult females to juveniles was 1∶0.56, which is higher than the ratio recorded in spring (1∶0.43) or summer (1∶0.44).The results showed that the Helan Mountains State Nature Reserve has succeed in protecting blue sheep.展开更多
基金This study was supported financially by the National Nature Science Foundation of China(Grant No.30470231)the Ministry of Education of People’s Republic of China,the State’s Tenth Five-year Program“211 project”-supported Key Academic Discipline Program of ECNU,and Chinese Postdoctoral Science Foundation(No.2005037496).
文摘The feeding habitat selection of blue sheep(Pseudois nayaur)was studied by direct observation method in the Helan Mountains,China during winter(from Novembe r to December)and spring(from April to June)from 2003 to 2004.We established 25 line transects to collect information on feeding habitats used by blue sheep.Blue sheep in the study area preferred mountain savanna forests,a habitat dominated by Ulmus glaucescens,with medium tree density(<4 individuals/400 m^(2)),moderate tree height(4-6 m),higher shrub density(>5 individuals/100 m^(2)),higher shrub(>1.3 m),higher food abundance(>50 g),moderate distance to human disturbance(<500 m),and mild distance to bare rock(<2 m).Such habitats characterized by 12 ecological factors were preferred as feeding areas by blue sheep during winter.Similar to habitat selection by the species during winter,blue sheep also showed a preference for mountain savanna with tree dominated by Ulmus glaucescens and medium tree density(<4 individuals/400 m^(2))during spring.Nevertheless,blue sheep preferred medium tree height(<6 m),moderate tree density(5-10 individuals/100 m^(2)),medium shrub height(1.3-1.7 m),higher food abundance(>100 g),moderate altitude(<2000 m),moderate distance to water resource(<500 m),and medium hiding cover(50%-75%)during spring.Selection of the feeding habitats by sheep showed a significant difference in vegetation type,landform feature,dominant tree,tree height,shrub density,distance to the nearest shrub,food abundance,slope direc-tion,slope degree,distance to water resource,and hiding cover between winter and spring.Results of principal com-ponents analysis indicated that the first principal component accounted for 24.493%of the total variance among feeding habitat variance during winter,with higher loadings for vegetation type,dominant tree,tree height,distance to the nearest tree,shrub density,shrub height,altitude,distance to water resource,and distance to human disturbance.In spring,the first principal components explained 28.777%of the vari-ance,with higher loadings for vegetation type,distance to the nearest tree,shrub height,distance to the nearest shrub,food abundance,altitude,and distance to human disturbance.
文摘Group size and composition of blue sheep(Pseudois nayaur)were studied in the Helan Mountains, Ningxia Autonomous Region from November to December 2003.We scanned mountain slopes with binoculars and observed with 20-60× spotting-scope. A total of 310 herds of blue sheep and 1 336 individuals were observed during the study period. Blue sheep were frequently seen in small herds of 2 to 8 individuals, which represent 94.8% of total herds observed. Herds consisting of 9 individuals or more represented 5.2%. The largest herd we observed numbered 51 individuals. Mean group size was 4.2 individuals. Blue sheep herds can be divided into three types: male herds (composed solely of males), female herds (consisting of females with or without juveniles of both sexes), and mixed herds (including adult males, females, and subadults).Among the 310 herds, female herds were counted 150 times(48.4%), mixed herds 154 times(49.7%), and male herds 6 times(1.9%). Of 1 336 blue sheep classified by sex and age, adults, subadults and juveniles composed 64.1%,20.8%, and 15.1% respectively. The female:male ratio of adults was 1∶0.73. The ratio of adult females to juveniles was 1∶0.56, which is higher than the ratio recorded in spring (1∶0.43) or summer (1∶0.44).The results showed that the Helan Mountains State Nature Reserve has succeed in protecting blue sheep.
