by Shyamala Ratnayeke
Page 1 : About the Sloth Bear
It is June at Wasgomuwa National Park. The rains have ceased, and hot dry winds have parched the grass and dried many of the smaller waterholes and streambeds. Many of the elephants are still around, although by this time most herds should have embarked on their yearly migration to Minneriya and Giritale, where water and fodder are more plentiful. Toward the south of the park, open plains of dry grassland dotted with scrub and forest dominate the landscape. Across the Wilmitiya plains, steep mountain escarpments form a spectacular horizon. As one moves northward the habitat changes to dense forest, most of it covering undulating hills that grade into the steeper slopes of the Sudhukanda range along the western boundary of Wasgomuwa. The elephants and buffalo seem plentiful on the plains, the forest rich with bird life, and one may see the occasional sambar. Less obvious to either casual or seasoned visitors are the shy, more nocturnal, jungle inhabitants who rarely make an appearance. Who would imagine that this area is home to what may possibly be Sri Lanka’s highest density of sloth bears?
Sloth bears belong to the order Carnivora, a highly eclectic group of mammals deriving from a common predatory or flesh-eating ancestry. Modern Carnivora are highly variable in dietary habits and modes of food acquisition, ranging from committed flesh-eaters in the cat family to the largely frugivorous ursids. The Ursidae, or bear family, is a small group comprising eight species distributed almost predominantly in the Northern Hemisphere. The sloth bear (Melursus ursinus) is found in India, Sri Lanka, Bangladesh, Nepal and Bhutan. Sloth bears specialize on insects, especially termites, which form a dietary staple, and possess special morphological adaptations for myrmecophagy (termite-eating): a broad extended palate, protrusible lips, nostrils that can seal shut, a missing pair of middle upper incisors, and powerful claws for digging.
The subspecies of the sloth bear (M. ursinus inornatus) is endemic to Sri Lanka, and some anecdotal evidence suggests that this bear may be somewhat ecologically and behaviorally unique. The sloth bear is listed as “vulnerable” by the IUCN, although data on the bear’s population status for most of its range is sketchy. There is general consensus, however, that existing sloth bear populations, including those in Sri Lanka, are becoming increasingly fragmented, that the bear has disappeared from many areas of its former range, and that sloth bear populations outside protected areas are very likely decreasing or have disappeared entirely.
Shyamala Ratnayeke and her research team are on the trail of the first six radio-collared sloth bears in Sri Lanka. The study is a joint effort between the University of Tennessee, the Open University of Sri Lanka, and the Sri Lanka Department of Wildlife Conservation (DWLC), to learn more about this rarely seen enigma of the Sri Lankan jungles. The project on the sloth bear is supported through the American Zoo and Aquarium Association, the U. S. National Science Foundation and the University of Tennessee. Funding from the International Bear Association, the Chicago Zoological Society and Sveriges Rovdjurscentrum-Orsa Grönklitt will enable the sloth bear study to continue in 2004.
Apart from Ratnayeke, the three main investigators include Dr. Padmalal, a wildlife biologist and senior lecturer at the Open University of Sri Lanka and Dr. Frank van Manen, carnivore biologist at the University of Tennessee.
Next Page : Telemetry as a Research Tool
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