Relative ungulate abundance in a fragmented landscape: Implications for tiger conservation

Degradation and fragmentation of habitats in the southern lowlands (Terai) of Nepal have restricted many wide ranging large mammals into small isolated protected areas. Information, important for developing conservation strategies and evaluating management interventions, is not available for the Terai landscape. This study: (1) determined distribution and abundance of tiger prey species in the Terai, (2) classified vegetation using satellite imagery and used the results to identify priority areas for conservation, and (3) determined decay rates of pellet groups produced by important tiger prey species. Habitat variables and ungulate pellet groups were measured in 10 m2 circular plots spaced 25 m apart along 625 m straight line transects. A hybrid approach was used for vegetation classification of five satellite scenes. Pellet decay rates were determined by monitoring cohorts of pellet groups from every month for a year. Poisson regression analysis was used to develop a model to predict ungulate abundance. Finally, a grid cell approach was undertaken to create a prey abundance map for the Terai using geographical information system (GIS). A total of 772 transects distributed in various forest management systems was surveyed for ungulate pellet groups in the forested landscape of the Terai. Medium sized prey species (0.6 +/- 0.04) were more abundant than small (0.04 +/- 0.01) and large (0.14 +/- 0.02) prey. Prey abundance was higher in protected areas but similar in forests outside protected areas. Human disturbance and livestock grazing had a negative effect on ungulate abundance. Floodplains with riverine forest and grasslands were rich in ungulates; this type of habitat was scarce outside protected areas. The model predicted prey abundance accurately in different habitat types across the landscape.; This study provides information on distribution and abundance of ungulates and their link to habitat characteristics at a landscape scale. Additionally, it developed and tested a monitoring strategy to evaluate management interventions, primarily restoration of degraded lands in partnership with local communities across the Terai. Nepal's national forests, although experiencing different levels of degradation, have tremendous conservation potential to ensure long term viability of large mammals (e.g. tigers) if restored and integrated into landscape level conservation plans across the Terai.