Distribution and Conservation Status of Shortridge's Capped Langurs
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Distribution and conservation status of Shortridge’s capped langurs Trachypithecus shortridgei in China L IANG-WEI C UI,YING-CHUN L I ,CHI M A ,MATTHEW B. SCOTT,JIN-FA L I X IAO-YANG H E ,DONG-HUI L I ,JUN S UN,WEN-MO S UN and W EN X IAO Abstract We conducted community interviews and field and in south-western China in the Nu and Dulong valleys surveys to determine the distribution and population of (Pocock, ; Groves, ; Htun et al., ). Numbers the Endangered Shortridge’s capped langur Trachypithecus of individuals are assumed to be low and declining as a result shortridgei, and the threats to the species, in the Dulong and of a restricted geographical range, hunting pressure and Nu River valleys of north-western Yunnan Province, China. widespread deforestation for agriculture and timber extrac- We found that c. groups of T. shortridgei reside in the tion. The total population is believed to have declined by at Dulong valley, mostly located in the southern portion of least % since , primarily as a result of hunting and the valley. According to interview and observational records habitat loss (Htun et al., ). Consequently, T. shortridgei in the Gaoligong Mountains to the west of the Nu River, is categorized as Endangered on the IUCN Red List (Htun individuals and no groups were observed. Family groups et al., ) and is listed in CITES Appendix I (CITES, consist of one adult male, – adult females and up to five ). In China it is a Category I protected species under young. We estimate the population of T. shortridgei in Chinese animal conservation laws, and in Myanmar it is China to be c. – individuals. Threats to the species protected under the national Wildlife Protection Law include habitat loss and poaching. We suggest several (Htun et al., ). measures to conserve T. shortridgei, such as a review of To achieve more successful management, a better under- the Gaoligong National Nature Reserve management strat- standing of the species is needed, including population size, egy, and increasing engagement, education, inclusion of distribution, threats, and impediments to its conservation. local people in forest management, and the consistency of There are no population data available from Myanmar enforcement. (Htun et al., ), and the distribution and population data from China are outdated and based on scant field Keywords Endangered species, hunter interviews, local data collected using unclear or dubious methodologies. Li knowledge, population estimation, Shortridge’s capped & Lin () suggested the range of T. shortridgei in China langur, species distribution, Trachypithecus shortridgei encompassed the length of the Gaoligong Mountains, based on a single male specimen collected in the Dulong valley in . Ma & Wang () estimated the total population size to be – individuals in the Dulong valley, but pro- Introduction vided little detail of how these estimates were made. Wang hortridge’s capped langur Trachypithecus shortridgei ( ) confirmed the presence of T. shortridgei on the east- (Wroughton, ) is a colobine primate that inhabits ern slopes of the Gaoligong Mountains west of the Nu River, S – low to mid-elevation evergreen and semi-evergreen forests and Xu ( ) estimated these populations comprised – east of the Chindwin River in north-eastern Myanmar, individuals in groups. The latest estimate indicated a total population in China of c. individuals, with , , km of suitable habitat (Forestry Department of Yunnan LIANG-WEI CUI*† (Corresponding author), YING-CHUN LI†,JIN-FA LI and WEN- Province, ). MO SUN Forestry Faculty, South-west Forestry University, Kunming, Yunnan, 650224, China. E-mail [email protected] The presumed range of T. shortridgei spans a mostly contiguous forest ecosystem that includes northern CHI MA,MATTHEW B. SCOTT and WEN XIAO (Corresponding author) Institute of Eastern-Himalaya Biodiversity Research, Dali University, Dali, Yunnan, 671003, Kachin State, Myanmar and the Dulong and Nu River val- China. E-mail [email protected] leys (Htun et al., ). The low human population and in- XIAO-YANG HE ,DONG-HUI LI and JUN SUN Nujiang Administration Bureau, accessibility of the region have protected its biodiversity Gaoligongshan National Nature Reserve, Liuku, Yunnan, China (Myers et al., ; Mittermeier et al., ); however, the *Also at: Key Laboratory of Resource Biology and Biotechnology in Western region is beleaguered by an increasing number of environ- China, College of Life Sciences, Northwest University, Xi’an, China †These authors contributed equally to this work. mental and socio-economic problems relating to poverty, Received September . Revision requested October . civil unrest, illegal logging, smuggling of wildlife, drug traf- Accepted March . First published online May . ficking, and hydro-development (Xu & Wilkes, ; Kahrl Oryx, 2016, 50(4), 732–741 © 2015 Fauna & Flora International doi:10.1017/S0030605315000319 Downloaded from https://www.cambridge.org/core. IP address: 170.106.35.93, on 28 Sep 2021 at 02:02:51, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0030605315000319 Shortridge’s capped langurs in China 733 et al., ; EIA, ; Wang et al., ; Burma Rivers (Jones et al., ). Within the Dulong and Nu catchments Network, ). Identifying and quantifying some of the we established a targeted area on the basis of information threats to biodiversity in the region, and impediments to gleaned from park reports (Xu, ), historical reports its protection, specifically in relation to T. shortridgei, will (Ma et al., ), regional reserve managers, and visual as- facilitate better-informed management decisions. We there- sessment of satellite imagery for potential habitat (Ma fore determined the distribution and population size of et al., ). We conducted a series of interview surveys in T. shortridgei in China as a benchmark for future monitor- the Dulong valley during – July and – ing, and report and evaluate local factors threatening the November , and west of the Nu River in the species. We propose practical strategies for local conserva- Gaoligong Mountains during April– August . tion actions and ecosystem protection. Our interview subjects were mostly local people living in or near forests within the target search area. Interview sub- jects were identified through snowball sampling (Newing Study area et al., ), beginning with the local leader in each village. We made a particular effort to select hunters and family el- We conducted the survey in the Dulong (Irrawaddy) and Nu ders with intimate, long-standing knowledge of the forest (Salween) River catchments in north-west Yunnan Province environment. We also interviewed numerous active forest in south-west China (Fig. ). Both river systems have their patrollers and regional forest managers of Gaoligongshan headwaters on the Tibetan plateau and flow southwards, National Nature Reserve. Interviews were brief, informal forming deeply incised parallel valleys flanked by mountain and unstructured (Xiang et al., , ; Fan et al., ranges . , m. The topographic and climatic variation ). During the interviews we tested whether respondents in the region results in a variety of natural habitat types, could describe morphological characteristics of T. shortrid- from subtropical broadleaved evergreen forest to high-alpine gei, and whether they could identify T. shortridgei correctly heath and meadows. Forests account for . %ofthearea from pictures of local primates, including Trachypithecus pi- (Weyerhaeuser et al., ). The climate is dominated by leatus, Trachypithecus phayrei, Rhinopithecus strykeri, the East and South Asia monsoons, with precipitation occur- Macaca arctoides, Macaca assamensis and Hoolock leucone- ring mostly in the warm season during May–October. Winter dys. If respondents could distinguish the species accurately tends to be cool and dry throughout the region. As a result of we recorded all personal encounters with T. shortridgei, in- its steep topographic and climatic gradients, and unique bio- cluding time and date, location, group size, and group com- geography, the region has globally significant levels of bio- position when possible. diversity and endemism, with several distinct ecosystems During the interview survey period we also assessed the (Myers et al., ; Mittermeier et al., ; UNESCO, a). scope and magnitude of threats to T. shortridgei by gather- The Dulong River and upper Nu River catchments are ing knowledge on the trapping success for T. shortridgei and inhabited by members of . ethnic minority groups, other species, and on other community livelihood strategies including Dulong (also written as Drung), Lisu, Nu and that interact with the local habitat. As hunting and trapping Tibetan, who practise a variety of livelihood strategies, in- protected species is illegal in China we recognized the sen- cluding small-scale agriculture, food and medicine gather- sitive nature of some interview data. Several approaches (e.g. ing, transhumant grazing, swidden agriculture, trade, and the randomized response technique and the nominative hunting and trapping (Buntaine et al., ). Local econ- technique) have been developed to collect data about illegal omies and many livelihood strategies have changed as a re- behaviour when perpetrators fear prosecution or repercus- sult of infrastructue development, population growth, sions (St. John et al., ). However, we found most com- market shifts, and government subsidies and regulations, munities were generally open and candid