Social Organization, Diet, Time Budgets And Habitat Use Of Shortridge’s Capped Langur(Trachypithecus Shortridgei) At The Dulongjiang Valley In Yunnan, China

Trachypithecus shortridgei is categorized as Endangered on the IUCN Red List and is listed in CITES Appendix I. The information about this species in China is still absent, except that they inhabits in forests at the Dulongjiang Valley, with ca. 250-370 individuals in 19 populations. This study is designed to preliminary study social organization, diet, time budget and habitat use of T. shortridgei at Silaluo in the Dulongjiang valley from August 2012 to October 2013. Iinformation on habit and behavior of this species are important for making protection actions. At the same time, it can provide valuable information for scientific research of nature reserve and the management. It will promote species diversity protection and the sustainable development of resources at the Dulongjiang Valley.We collected data on social organization of five groups of T. shortridgei at Silaluo in the Dulongjiang Valley around a year. The species is composed of harems, which consist of one adult male, two-three adult females and their immature offspring, and its mean group size is 8(range: 7 to 9) with a adult sexual ratio of adult male to adult female(1 : 2.9), of infants to adult females(1:2.2) and of adults to immatures(1 : 1.2),which indicates a potential of population increase. T. Shortridgei give birth from March to July, its interbirth interval is 2 years.Data on feeding patterns and time budget were collected by scan sampling at 10-min intervals. The results showed that 38 families 51 species of plants were chosed by T.Shortridgei, main food species included Macrothamnium macrocarpum with Scapania verrucosa, Saurauia napaulensis, Dendropanax yunnanensis, Schefflera octophylla,lindsaea,odorate, Turpinia dulongensis, Meliosma oldhamii, Ilex godajam and Dipentodon sinicus. The langurs spent 1.6% of daytime for buds, 41.6% for leaves,5.6% for flowersr, 24.3% for fruits,.2.9% for plants, 15.4% for moss and 1.8% for other plant parts(bamboo and barkand and so on). The langurs displayed daily and seasonal variation in selecting food parts choice.Food species of T. Shortridgei is also widely used by local people, so it is necessary to protect its food species.T. Shortridgei spent 38.7% of daytime in feeding, 33.2% in resting, 24.9% in moving, 1.8% in grooming and 1.4% in playing. The langurs showed daily and seasonal rhythm, and also different age-sex classes of time budget. Time budget of the langurs didn’t relate with the temperature, but with the rainfall.Data on habitat use were collected by 30-min scan sampling. T. Shortridgei prefered evergreen broad-leaf forest, bushwood and cliff, but also tended to choice different kinds of habitat at different seasons. Different groups used different habitat.Although T. Shortridgei tended to stay at the canopy of tree all the year, they also use others tree stratum at different seasons. The home range of study groups was estimated to be 37.5-162.5 ha2, each of which had its own home range with some overlapped areas with others. Different groups were observed to range at different periods in the study areas, so they might avoid meering each other at the same time.