COMPARATIVE ECOLOGY OF TWO MONGOOSE SPECIES (Herpestes javanicus and H. edwardsii) INHABITING POTHWAR PLATEAU

Abstract

Two species of mongooses; small Indian mongoose (Herpestes javanicus) and the grey mongoose (H. edwardsii) occur in many parts of Pakistan including the Pothwar Plateau. They are diurnal, terrestrial carnivores playing their ecological role in controlling populations of snakes, rodents and insects. The current study investigated their distribution, vegetation analysis of their habitat, population, and diet composition in the Pothwar Plateau. Distribution of the two mongoose species was recorded through reconnaissance surveys of the study area, vegetation analysis was carried out by quantifying trees (Point-Centered-Quarter method), shrubs and herbs (by Quadrate method). The populations of the two species were estimated by direct enumeration by minimum numbers alive (MNA) index using capture, mark, and recapture data and indirect enumeration, using active burrows (AB) count method. Diet composition of the two species was investigated by their scat analysis. The small Indian mongoose was found distributed in the vicinity of human dwellings, whereas, the grey mongoose was widely distributed in natural areas with low human activity, however, both species were found occupying the cultivated areas. Their distribution was found restricted below 850 m asl in the study area. Vegetation analysis of the habitat of two mongoose species showed Zizyphus mauritiana with high importance value index (IVI = 101.21) and Acacia nilotica (IVI = 95.13) as major tree species, Zizyphus nummularia (IVI = 90.29) as major shrub and 24 Cynodon dactylon (IVI = 20.70), Peganum harmala (IVI = 19.37) and Carthamus oxycantha (IVI = 18.24) as major herb species. burrows activity of both mongoose species was found highly associated with the Zizyphus mauritiana (50% and 46%, respectively). Average population density of small Indian mongoose was 7.91 ± 0.41 per km2 (by MNA) and 12.49 ± 0.4 per km2 (by AB method), whereas, that of grey mongoose was 7.17 ± 0.52 per km2 (by MNA) and 11.70 ± 0.33 per km2 (by AB method). Live trapped mongooses showed a sex ratio (M : F) of 0.73 (small Indian mongoose) and 0.78 (grey mongoose), indicating more female-biased population in the study area. Burrows depth and diameter as well as body measurements (body weight, body length and tail length) of the grey mongoose (n=72) were greater than those of the small Indian mongoose (n=72). Analysis of scat samples of the two mongoose species revealed hairs, feathers, insect body remains and plant matter and seeds along with some unidentified material. Identification of rodent prey species from recovered hairs showed that small Indian mongoose preys upon three different rodent species while the grey mongoose consumes five different rodent species in the study area. Insects consumed by both mongoose species belong to five different orders. Food niche breadth of the two species varied among different seasons of the year. Food niche overlap between the two species was found to be 0.95. The study concludes that the two sympatric mongoose species vary in their abundance along a gradient of human activity. Ecologically and morphologically, similar species (small Indian mongoose and grey mongoose) living in sympatry in the Pothwar Plateau partition their resources, though resources themselves may vary in time and space and in relation to extrinsic factors.