Home Ranges and Habitat Use of Sloth Bears Melursus Ursinus Inornatus in Wasgomuwa National Park, Sri Lanka Author(s): Shyamala Ratnayeke, Frank T. van Manen, U. K. G. K. Padmalal Source: Wildlife Biology, 13(3):272-284. Published By: Nordic Board for Wildlife Research DOI: http://dx.doi.org/10.2981/0909-6396(2007)13[272:HRAHUO]2.0.CO;2 URL: http://www.bioone.org/doi/ full/10.2981/0909-6396%282007%2913%5B272%3AHRAHUO%5D2.0.CO%3B2 BioOne (www.bioone.org) is a nonprofit, online aggregation of core research in the biological, ecological, and environmental sciences. BioOne provides a sustainable online platform for over 170 journals and books published by nonprofit societies, associations, museums, institutions, and presses. Your use of this PDF, the BioOne Web site, and all posted and associated content indicates your acceptance of BioOne’s Terms of Use, available at www.bioone.org/page/terms_of_use. Usage of BioOne content is strictly limited to personal, educational, and non-commercial use. Commercial inquiries or rights and permissions requests should be directed to the individual publisher as copyright holder. BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers, academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research. Home ranges and habitat use of sloth bears Melursus ursinus inornatus in Wasgomuwa National Park, Sri Lanka Shyamala Ratnayeke, Frank T. van Manen & U.K.G.K. Padmalal Ratnayeke, S., van Manen, F.T. & Padmalal, U.K.G.K. 2007: Home ranges and habitat use of sloth bears Melursus ursinus inornatus in Was- gomuwa National Park, Sri Lanka. - Wildl. Biol. 13: 272-284. We studied home ranges and habitat selection of 10 adult sloth bears Melursus ursinus inornatus at Wasgomuwa National Park, Sri Lanka during 2002-2003. Very little is known about the ecology and behaviour of M. u. inornatus, which is a subspecies found in Sri Lanka. Our study was undertaken to assess space and habitat requirements typical of a vi- able population of M. u. inornatus to facilitate future conservation efforts. We captured and radio-collared 10 adult sloth bears and used the telem- etry data to assess home-range size and habitat use. Mean 95% fixed kernel home ranges were 2.2 km2 (SE 5 0.61) and 3.8 km2 (SE 5 1.01) for adult females and males, respectively. Although areas outside the national park were accessible to bears, home ranges were almost exclu- sively situated within the national park boundaries. Within the home ranges, high forests were used more and abandoned agricultural fields (chenas) were used less than expected based on availability. Our estimates of home-range size are among the smallest reported for any species of bear. Thus, despite its relatively small size, Wasgomuwa National Park may support a sizeable population of sloth bears. The restriction of hu- man activity within protected areas may be necessary for long-term via- bility of sloth bear populations in Sri Lanka as is maintenance of forest or scrub cover in areas with existing sloth bear populations and along po- tential travel corridors. Key words: conservation, habitat, home range, Melursus ursinus inornatus, sloth bear, Sri Lanka Shyamala Ratnayeke, Department of Forestry, Wildlife and Fisheries, Uni- versity of Tennessee, 274 Ellington Plant Sciences Building, Knoxville, TN 37996, USA - e-mail: [email protected] Frank T. van Manen, U.S. Geological Survey, Southern Appalachian Re- search Branch, 274 Ellington Plant Sciences, University of Tennessee, Knoxville, TN 37996, USA - e-mail: [email protected] U.K.G.K. Padmalal, Department of Zoology, Open University of Sri Lan- ka, Sri Lanka - e-mail: [email protected] Corresponding author: Shyamala Ratnayeke Received 16 January 2006, accepted 15 June 2006 Associate Editor: Andrew E. Derocher The sloth bear Melursus ursinus is a myrmecopha- Nepal, Bhutan, Bangladesh and Sri Lanka. The gous (ant- or termite-eating) ursid found in India, sloth bear is listed as 'vulnerable' by the World Con- 272 E WILDLIFE BIOLOGY ? 13:3 (2007) servation Union (IUCN 2004); the species’ range on the ecology of M. u. inornatus, our purpose was has become increasingly fragmented and many to determine home-range sizes and habitat use of sloth bear populations outside protected areas are sloth bears as a first step towards designing conser- believed to be decreasing or to have disappeared vation initiatives for this subspecies. We defined entirely (Krishnan 1972, Santiapillai & Santiapillai habitat as a set of environmental components (Gar- 1990, Servheen 1990, Garshelis et al. 1999b). shelis 2000, Morrison 2001), namely vegetation M. u. inornatus, one of two recognized subspecies types or human disturbance, within a defined area. of the sloth bear, is about O of the size of bears on We then tested whether sloth bears selected partic- the Indian mainland and tends to have shorter hair. ular habitat types to establish home ranges and if It is possibly Sri Lanka’s most vulnerable carnivore certain habitat types within home ranges were used (Santiapillai & Santiapillai 1990). Human densities more or less than expected. are high in Sri Lanka and both protected and un- protected areas experience poaching and human encroachment. Behavioural and life history charac- Material and methods teristics of sloth bears place them at risk throughout most of their range (Garshelis et al. 1999b). In many Study area portions of their range, sloth bears are rare where Our study site was located in Wasgomuwa National human disturbance is high. When disturbed, sloth Park (39,385 ha) in the central region (80u55'E, bears may respond aggressively and attack and in- 7u45'N) of Sri Lanka (Fig. 1). The national park jure humans (Santiapillai & Santiapillai 1990, Raj- is in the lowlands of Sri Lanka where the climate purohit & Krausman 2000), often resulting in their is classified as Tropical Dry Zone (Domro¨s 1974). persecution (S. Ratnayeke, unpubl. data). Sloth With respect to rainfall, the area is at the transition bears have one of the lowest reproductive rates of the intermediate and dry climatic zones of the among carnivores (Gittleman 1989) and, by virtue island. Most of the mean annual precipitation of of their size, may require large areas of relatively 1,800 mm occurs from November through January undisturbed habitat to maintain viable popula- (Pabla et al. 1998). Elevation ranges within 60- tions. Apart from a few studies in Nepal (Joshi et 200 m a.s.l. with undulating terrain intercepted by al. 1995) and India (Akhtar et al. 2004; K. Yoga- a long ridge (300-1,000 m) extending north-south. nand, pers. comm.), very little is known about the Temperatures are uniformly high throughout the use of space or habitats by the sloth bear (Garshelis year, with an annual mean of 32uC. The predomi- et al. 1999b). nant soil type of the national park is shallow to Myrmecophagous mammals tend to have small moderately deep reddish brown earths in low relief home ranges relative to their body size (McNab areas, narrow extents of alluvial soils adjoining riv- 1983, Shaw et al. 1985, 1987). Conversely, large ers and streams, and a complex of shallow gravelly Carnivora, such as ursids, have large home ranges reddish brown earths and regosols on steeper moun- (McLoughlin et al. 1999, Garshelis 2004) and may tain ridges (Pabla et al. 1998). demonstrate marked shifts in the location of their The national park has a high diversity of flora home ranges in response to seasonal changes in re- and fauna, including large herbivores, such as ele- sources (Garshelis & Pelton 1981, Blanchard & phants Elephas maximus, buffalo Bubalus bubalis, Knight 1991, Dahle & Swenson 2003). Home sambar Cervus unicolor, and spotted deer Axis axis. ranges can therefore provide valuable information Apart from sloth bears, 13 other species of Carni- for conservation because they reflect the metabolic vora occur in Wasgomuwa National Park, includ- needs and the distribution and abundance of re- ing the leopard Panthera pardus (S. Ratnayeke, un- sources, such as food and mates, in a population publ. data). The vegetation of Wasgomuwa Na- (McNab 1963, Harvey & Clutton-Brock 1981, Git- tional Park is broadly classified as dry monsoonal tleman & Harvey 1982, McDonald 1983). forest, which typically consists of a mosaic of veg- Within their geographical range, sloth bears use etation types differing in structure and composition a wide range of habitats (e.g. grasslands, scrub and (Jayasingham et al. 1992). forests in dry or wet regions; Garshelis et al. 1999b). The national park is bound by rivers on the In Sri Lanka, however, sloth bears are confined to north, east and west boundaries. On the northern the relatively remote areas of the dry zone lowlands boundary, the park is linked to other protected (Phillips 1984). In the absence of any empirical data areas to facilitate movements of elephants. Agricul- E WILDLIFE BIOLOGY ? 13:3 (2007) 273 Figure 1. Location of Wasgomuwa National Park, Sri Lanka, and the region of the park used to determine home ranges and habitat use of sloth bears during 2002-2003. Original habitat cover classes were derived from Pabla et al. (1998). Habitat types that occurred in very small proportions within home ranges were consolidated with habitat types of similar structural attributes or community composition. The buffer zone was a belt of forest on the east bank of the river, which is the eastern boundary. ture, village gardens and settlements occur on the bears. The animal handling protocol was reviewed southern boundary of the national park. The east- and approved by DWLC veterinarians, and a re- ern boundary has a 300-500 m buffer zone of forest, gional DWLC veterinarian attended every capture along which are agricultural fields and scattered to assist with immobilization and handling.