Assessing tiger corridor functionality with landscape genetics and modelling across Terai-Arc landscape, India

India led the global tiger conservation initiatives and has doubled its wild tiger population to 2967 (2603-3346) since 2006. As the extant habitats are shrinking continuously, the persistence of these growing populations can only be ensured through focused landscape-scale conservation planning across all the existing tiger landscapes of Indian. We used intensive field-sampling, genetic analyses and GIS modelling to investigate tiger population structure, source-recipient dynamics and functionality of the existing corridors across the Indian part of Terai-Arc landscape (TAL). Using a 13 microsatellite marker panel we identified 219 individual tigers across Indian TAL. Further genetic analyses revealed three weakly, but significantly differentiated tiger subpopulations, termed as 'Tiger Genetic Blocks (TGBs)'. Genetic migrant detection and gene flow analyses distinguished seven source and 10 recipient areas within this landscape. Circuitscape analyses ascertained total 19 (10 high, three medium and six low conductance) corridors across this landscape, of which 10 require immediate conservation attention. Overall, the tiger populations residing in the western, central and eastern TAL still maintain functional connectivity through these corridors. We suggest urgent management plan involving habitat recovery and protection of similar to 2700 sq. km . identified area to establish landscape connectivity. Further, mitigation measures associated with ongoing linear infrastructure developments and transboundary coordination with Nepal will ensure habitat and genetic connectivity and long-term sustainability of tigers in this globally important landscape.

Automated summary

India has led global tiger conservation efforts and doubled its wild tiger population since 2006. To ensure the persistence of these growing populations in shrinking habitats, focused conservation planning is needed across all existing tiger landscapes in India. Through field-sampling, genetic analyses, and GIS modelling, the study investigated tiger population structure, source-recipient dynamics, and functionality of corridors in the Terai-Arc landscape of India.