title: Social organization of Shortridge's capped langur (Trachypithecus shortridgei) at the Dulongjiang Valley in Yunnan, China.
abstract: 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 1970s, 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.
authors.affiliation: Forestry Faculty, Southwest Forestry University, Kunming, Yunnan 650224, China.
authors.forename: Ying-Chun
authors.initials: YC
authors.lastname: Li
authors.affiliation: Forestry Faculty, Southwest Forestry University, Kunming, Yunnan 650224, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
authors.affiliation: Nujiang Administration Bureau, Gaoligongshan National Nature Reserve, Liuku, Yunnan 673100, China.
authors.forename: Xiao-Yang
authors.initials: XY
authors.lastname: He
authors.affiliation: Institute of Eastern-Himalaya Biodiversity Research, Dali University, Dali, Yunnan 671003, China.
authors.forename: Chi
authors.initials: C
authors.lastname: Ma
authors.affiliation: Nujiang Administration Bureau, Gaoligongshan National Nature Reserve, Liuku, Yunnan 673100, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Sun
authors.affiliation: Nujiang Administration Bureau, Gaoligongshan National Nature Reserve, Liuku, Yunnan 673100, China.
authors.forename: Dong-Hui
authors.initials: DH
authors.lastname: Li
authors.affiliation: Institute of Eastern-Himalaya Biodiversity Research, Dali University, Dali, Yunnan 671003, China.xiaowen.dali@gmail.com.
authors.forename: Wen
authors.initials: W
authors.lastname: Xiao
authors.affiliation: Forestry Faculty, Southwest Forestry University, Kunming, Yunnan 650224, China;College of Life Sciences, Northwest University, Xi'an, 710069, China. gcuilw@gmail.com.
authors.forename: Liang-Wei
authors.initials: LW
authors.lastname: Cui
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D002520:Cercopithecidae / Q000502:physiology / Q000523:psychology*; D002681:China; D017753:Ecosystem; D005260:Female; D008297:Male; D012919:Social Behavior
keywords: Group size; Multi-male, multi-female group; One-male, multi-female group; Social organization; Trachypithecus shortridgei