Non-human primates often live in socially stable groups characterized by bonded relationships among individuals. Social organization can be used to evaluate living conditions and expansion potential. Bisexual group si...Non-human primates often live in socially stable groups characterized by bonded relationships among individuals. Social organization can be used to evaluate living conditions and expansion potential. Bisexual group size, ratio of males to females and group composition are essential elements determining the type of social organization. Although the first report on Shortridge’s capped langurs(Trachypithecus shortridgei) was in the 1970 s, until now, the species only inhabits forests of the Dulongjiang valley in northwest Yunnan, China, with c. 250-370 individuals in 19 populations. To understand its social organization, we collected data from five groups of Shortridge’s langurs at Silaluo in the Dulongjiang valley during August 2012-October 2013. Family groups consist of one adult male, 2–3 adult females and up to five young. Group size averaged 8(7-9) individuals. The ratio of adult males to females(M/F) was 1:2.9, infants to adult females was(I/F) 1:2.2; and ratio of adults to immatures was 1:1.2, indicating the potential of a population increasing. Birth season was during March-July and the inter-birth interval was two years.展开更多
基金supported by the Yunnan Green Environmental Development Fundthe Central Financial Assistance Fund+3 种基金the National Natural Science Foundation of China(31160422,30960084)the Program for New Century Excellent Talents in University(NCET-12-1079)the China Postdoctoral Science Foundation(2013M542379)the Key Subject of Wildlife Conservation and Utilization in Yunnan Province
文摘Non-human primates often live in socially stable groups characterized by bonded relationships among individuals. Social organization can be used to evaluate living conditions and expansion potential. Bisexual group size, ratio of males to females and group composition are essential elements determining the type of social organization. Although the first report on Shortridge’s capped langurs(Trachypithecus shortridgei) was in the 1970 s, until now, the species only inhabits forests of the Dulongjiang valley in northwest Yunnan, China, with c. 250-370 individuals in 19 populations. To understand its social organization, we collected data from five groups of Shortridge’s langurs at Silaluo in the Dulongjiang valley during August 2012-October 2013. Family groups consist of one adult male, 2–3 adult females and up to five young. Group size averaged 8(7-9) individuals. The ratio of adult males to females(M/F) was 1:2.9, infants to adult females was(I/F) 1:2.2; and ratio of adults to immatures was 1:1.2, indicating the potential of a population increasing. Birth season was during March-July and the inter-birth interval was two years.