Among the major challenges inherent in the conservation of large mammals is the necessity to maintain connectivity between disjunct populations, which can buffer them from the negative effects of demographic stochasticity and inbreeding. In the Periyar – Agastyamalai landscape of the southern Western Ghats, tiger (Panthera tigris) and elephant (Elephas maximus) populations were historically connected through a contiguous stretch of prime habitat. However, Periyar and Agastyamalai are now separated by the Shencottah Gap: a complex mix of land use types, human settlements and linear barriers. Restoration of landscape-level connectivity is a conservation necessity; consequently, there has been increasing interest over the past few years in corridor restoration in this landscape.
Despite recognition of the importance of connectivity, however, actual conservation planning and implementation of corridors has been hampered by the lack of fundamental scientific information critical to corridor design. The primary goal of this study was to provide a quantitative, scientific basis for connectivity restoration by empirically identifying corridors for seven focal large mammal species. We collected data on animal distribution and occurrence, related these to a wide range of habitat variables, and modelled potential corridors across the Shencottah Gap at a coarse scale. We also collected a wide range of socio-economic data to characterize settlements in this area, thus developing a profile of local communities and their relationship with wild habitat.
Our results show several gaps in connectivity for all focal species as a result of variation in habitat quality. Nevertheless, empirical data shows two regions through which animal movement can potentially be restored over the long term, given adequate institutional support. These occur in the western and eastern parts of the study area, and we have named them the MSL and Kottavasal corridors respectively (after the settlements near which they pass). Each corridor has its own advantages and disadvantages in terms of biological value and human presence. From the conservation perspective, restoration of both corridors would be most beneficial, because it would provide multiple movement routes for large mammals and hence stabilize the system as a whole. However, both of them pass through, or close to, a variety of land use types, including forest patches, forestry plantations, private landholdings and settlements. Thus, restoration of these corridors will of necessity involve setting aside forest patches and engaging with local landowners to encourage wildlife-friendly practices on private land. Further, the presence of active community based groups (such as Vana Samrakshana Samithi, VSS and EcoDevelopment Committee, EDC) in the landscape can potentially be used to improve wildlife habitat in multiple-use areas within Reserve Forests .