SPECIES COMPOSITION OF HABITAT OCCUPATION BY VERTEBRATE AND SOME INVERTEBRATE FAUNA IN THE VICTORIA· RANDENIGALA· RANTAMBE(VRR)SANCTUARY, SRI LANKA

Abstract

A survey was carried out during April 1996 to March 1997 to assess the faunalcomposition and their habitat occupation in the VRR sanctuary (42,078 ha) as aprerequisite for the preparation of a management plan for the sanctuary. Fauna wasrecorded in relation to their major habitat types, by both direct and indirect observations.The terrestrial habitats were grouped according to the vegetation types and includednatural vegetation types such as dense forest (ll,200 ha) and riverine forests (500 ha).Man-influenced vegetation types consisted of open forests/savanna (6,330 ha), scrublands(7,590 ha), grasslands (1,725 ha) and home gardens (1,565 ha). The aquatic habitatsincluded flooded wetlands (paddy fields 1,070 ha, marshes/swamps/riparian zones 500 ha)and permanent water bodies (reservoirs - 5,580 ha, and 950 kilometers of stream and riversystems). The survey indicates that the VRR sanctuary harbours approximately 45% and19% of the total native and endemic vertebrate species of Sri Lanka, respectively. Thevertebrates included 30 species of fish (six endemics), 20 species of amphibians (eightendemics), 35 species of reptiles (eight endemics), 153 species of birds (12 endemics) and29 species of mammals (one endemic). The two invertebrate groups included 71 species ofbutterflies (3 endemic) and 41 species of molluscs (31 endemics). When considering thepercentage habitat occupation of the above taxa, the man-influenced habitats accounted for53% of the species (open forests/savannas - 20%, scrublands- 15%, home gardens 12% andgrasslands 6%), while the natural vegetation supported 31% of the species (dense forests -17%, and riverine forests-I 4%). The two groups of aquatic habitats harboured a similarproportion of species (flooded wetlands - 8% and permanent aquatic habitats 8%).