Identifying realistic recovery targets and conservation actions for tigers in a human‐dominated landscape using spatially explicit densities of wild prey and their determinants

Abstract

AbstractAimSetting realistic population targets and identifying actions for site and landscape‐level recovery plans are critical for achieving the global target of doubling wild tiger numbers by 2022. Here, we estimate the spatially explicit densities of wild ungulate prey across a gradient of disturbances in two disjunct tiger habitat blocks (THBs) covering 5212 km2, to evaluate landscape‐wide conditions for tigers and identify opportunities and specific actions for recovery.LocationWestern Terai Arc Landscape, India.MethodsData generated from 96 line transects in 15 systematically selected geographical cells (166.5 km2) were used to estimate spatially explicit densities of six wild ungulate prey species at a fine scale (1 km2). Employing distance‐based density surface models, we derived species‐specific estimates within three major forest land management categories (inviolate protected areas (PA),PAs with settlements and multiple‐use forests). By scaling estimated prey densities using an established relationship, we predicted the carrying capacity for tigers within eachTHB.ResultsSpecies‐specific responses of the six wild ungulates to natural‐habitat and anthropogenic covariates indicated the need for targeted prey recovery strategies. InviolatePAs supported the highest prey densities compared withPAs with settlements and multiple‐use forests, and specifically benefited the principal tiger prey species (chitalAxis axisand sambarRusa unicolor). The estimated mean prey density of 35.16 (±5.67) individuals per km2can potentially support 82 (62–106) and 299 (225–377) tigers acrossTHBI andTHB II, which currently support 2 (2–7) and 225 (199–256) tigers, respectively. This suggests a potentialc. 68% increase in population size given existing prey abundances. Finally, whileTHBI represents a potential tiger recovery site given adequate prey,PAs where resettlement of pastoralists is underway represent potential prey recovery sites inTHB II.Main conclusionsThis systematic approach of setting realistic population targets and prioritizing spatially explicit recovery strategies should aid in developing effective landscape conservation plans towards achieving global tiger conservation targets.