Study of Mammal Diversity in Xuan Nha and Muong Do Nature Reserves, Son La Province, Northwestern Vietnam

Abstract

The southern part of China and northern part of Indochina Peninsula are a ‘hot-spot’ of biodiversity (e.g., Cincotta et al. 2000; Cox and Moore 2005). This area also shows striking endemism of mammalian species; for instance, the giant panda Ailuropoda melanoleuca, saola Pseudoryx nghetinhensis, and Tonkin snub-nosed monkey Rhinopithecus avunculus are confined in this area (e.g., Wilson and Reeder 2005). Investigation of this area’s mammal fauna could have be insightful to the evolutionary history of mammals. Son La Province is located in this area, about 200 km west of Hanoi, Vietnam, at coordinates 20°39'–22°02'N, 103°11'–105°02'E. The province has total area of 14,055 km 2 , sharing about 250 km international border with Laos, and is characterized by very complex mountainous terrain, and tropical humid forest cover. The tropical forests contain high biodiversity values of national and international significance (Baltzer et al. 2001; MoNRE 2005; Tordoff et al. 2007). During recent decades, however, these biodiversity values have been seriously threatened and degraded due to increasing human population and rapid economic development. In situ conservation effort are necessary to halt biodiversity decline (Balmford et al. 1996; Sarat and Kalemani 2004); five nature reserves (NR) have been established or proposed by Son La Province to conserve its biodiversity values. Baseline biodiversity assessments of these NRs is required to develop strategies for effective NR management. In Son La Province, there are many mountains; different altitudes produce different distribution patterns of mammalian species (e.g., Chappel 1978). The wide altitudinal range, with variable topographic features, in Son La may promote different distribution patterns of mammalian species and high levels of species richness. To investigate this supposition in this area, we compared preliminary data on mammalian species richness between two NRs (Xuan Nha NR and Muong Do NR), which differ in elevation. As there are many species in biodiversity hotspot, this area could be suitable to examine differences of species diversity of mammals. The elevation of Xuan Nha NR ranges from 300 to ca. 2,000 m a.s.l., while that of Muong Do NR is lower (300 to ca. 1,000 m). We expect that number of mammalian species in Xuan Nha NR could be significantly more than that in Muong Do NR. We preliminary discuss the relationship between species richness and altitude on the Indochina Peninsula. This paper also presents an updated list of mammal species recorded in the NRs and evaluates their conservation importance. This study is the first mammal investigation in Muong Do NR, except bat surveys by Vu et al. (2009).