Distribution and habitat of the Laotian Rock Rat Laonastesaenigmamus Jenkins, Kilpatrick, Robinson & Timmins, 2005 (Rodentia: Diatomyidae) in Vietnam.

Dang Nguyen,Dinh Le,Duong Dinh,Nghia Nguyen,Duy Nguyen,Tri Dinh

doi:10.3897/bdj.2.e4188

Abstract

The Laotian Rock Rat Laonastes aenigmamus Jenkins, Kilpatrick, Robinson & Timmins, 2005 was originally discovered in Lao People's Democratic Republic in 2005. This species has been recognized as the sole surviving member of the otherwise extinct rodent family Diatomyidae. Laonastes aenigmamus was initially reported only in limestone forests of Khammouane Province, Central Lao. A second population was recently discovered in Phong Nha Ke Bang National Park (PNKB NP), Quang Binh Province, Central Vietnam in 2011. The confirmed distribution range of L. aenigmamus in Vietnam is very small, approximately 150 km2, covering low karst mountains in five communes of Minh Hoa District, Quang Binh Province, at elevations between 250 and 400 m asl. The Laotian Rock Rat inhabits the lower part of steep karst towers with many rock boulders and crevices under tall limestone evergreen forest. They use small rock crevices for their dens. The natural habitat of this species in PNKB NP has been affected by selected timber harvesting, however, a complex 3-4 layer forest structure is retained. The Laotian Rock Rat is omnivorous, feeding on parts (leaves, buds, fruits and roots) of 18 plant species and also some insects (cicada, mantis, grasshopper). The population of this species in PNKB NP is seriously threatened with extinction due to its very restricted distribution, high hunting pressure, and habitat disturbance. Laonastes aenigmamus is listed in the IUCN Red List as endangered and in the Wildlife and Aquatic Red List of Lao, however, this species has not been listed in the Red Data Book or any conservation legislative documents of Vietnam.

Highlights

The Laotian Rock Rat, Laonastes aenigmamus, was first discovered in 2005 in Lao People's Democratic Republic (Jenkins et al 2005)
In 2011, this species was recorded for the first time from Vietnam on the basis of four specimens trapped by local villagers in the buffer zone of Phong Nha Ke Bang National Park (PNKB NP), Central Vietnam (Nguyen et al 2012)
The habitat quality of the limestone forest in the areas bordering to the east and to the north of this distributional area has been seriously disturbed and is not suitable for the Laotian Rock Rat

Summary

Introduction

The Laotian Rock Rat, Laonastes aenigmamus, was first discovered in 2005 in Lao People's Democratic Republic (Jenkins et al 2005). The Laotian Rock Rat was previously found only in limestone forests of Khammouane Province, Central Lao (Jenkins et al 2005, Khotpathoom 2011, Vongsa 2010). During 2013 and 2014, we carried out 4 surveys in PNKB NP and adjacent areas to identify the distributional extent and habitat preference of the Laotian Rock Rat in Vietnam. The PNKB NP is located in the western part of Quang Binh Province, which borders Khammouane Province of Lao. The national park is characterized by very specific topographic conditions consisting of precipitous karst ridges, which rise to elevations of around 400 m. Distribution and habitat of the Laotian Rock Rat Laonastes aenigmamus Jenkins,. Drainage is complex and there are few permanent water sources

Materials and methods

Discussion