Abstract: Group living is the social behavior of ungulates, with important consequences on the responses of individuals and populations to environmental changes, and thus is considered as an important survival strategy to increase population fitness. The effects of food resources and predator risks on group living have been widely stu died. However, less is known about the impacts of habitat landscape features. Golden takin (Budorcas taxicolor bedfordi) is a typical group-living species. We collected spatial location information, age structure, and group size of each takin group in Shaanxi Sangyuan National Nature Reserve by extracting data from infrared cameras. The correlation between group structure and landscape factors, including slope and altitude, was calculated, with the aim to investigate the main topographical factors and their characteristics affecting the takin group living structure. The  results showed that: (1) Slope was significantly correlated with group size (r=0.336, P=0.006), while group size was not significantly associated with both elevation and aspect. (2) The influence of slope varied significantly between small size group (≤ 7 individuals) and big size group (> 7 individuals) (P=0.015). (3) The small size groups were mainly composed of adult takins, with a high proportion of male individuals, which preferred environment with small slope (12.42°±0.21°). The inter-specific competition is relatively strong in this area and vegetation composition is relatively rich. The big size groups were mainly family groups with a large proportion of takin juve niles and a high proportion of adult females, preferring to choose environment with a large slope (22.02°±0.95°). The competition between species is relatively small and the vegetation composition is relatively simple. The results indicated that slope was the main landscape factor affecting the scale, type, and structure of golden takin groups, and that the spatial environment and interspecific competition pressures selected by different groups were also signi ficantly different.

Key words: Sangyuan National Nature Reserve, takin group, infrared camera, slope.