Preliminary study on herpetofaunal diversity of Nilgala forest area in Monaragala district, Sri Lanka

Abstract

Nilgala ForestArea (NFA) is one of the largest and important forest area in Monaragala District, UvaProvince. It contain 12,432 hectares and lies within 7° 08' - 7° 14' NL and 81 D 16' - 81020' EL. Itselevation range between 200m to 700m within the Irindahela, Hangale, Yakun hela (highest point 700rn), Hamapola, Badangarnuwa, Keenagoda, Makada, Karadugala, Kukulagoda, Ewalahela, Gorikkadahills. The mean annual rainfall varies between where the average annual rainfall 1500mm - 2000mm(rain during northeast monsoon). while the mean annual temperature of the area is 28 DC - 31°C.The vegetation comprised with lowland tropical moist semi evergreen forest and savannah forest,home gardens and small patch paddy cultivations. The dominant tree species are Aralu (Terminaliachebulav, Bulu iTerminalia bellirica) and Nelli iPhyllanthus emblicay. Other than biodiversity,Nilgala is rich of archaeological monuments, such as prehistoric, proto-historic and historical Buddhistmonasteries.

During the two-year study period, total number of 70 reptile species were and 19 amphibian speciesrecorded. Reptiles include 44 genera of 17 families and 20 (28.5%) endemic species. Amphibianfauna contain 13 genera including 4 families and 6 (31.5%) endemic species. 41.4% (29) of reptilesand 26.3% (5) of Amphibians listed as 'Nationally Threatened' in the 1999 IUCN National threatenedlist. Out of70 species 38 (54.2%) are Serpentoid reptiles (11 endemics) and 32 (45.7%) species areof Tetrapod reptiles (9 endemics). Among the recorded species, 11 Serpentoid, 3 Tetrapod, and 2amphibians have not been recorded by previous workers. Furthermore seven unidentified specieswere also recorded during the survey, which probably include new amphibian species belonging togenus Nannophrys. Human activities such as man-made fire, ilIegallogging, extensive use of chemicalsfor agriculture, forest clearing for chena cultivation and road kills were identified as a main threat forthe natural habitats as well as faunal species.