Large connected landscapes are paramount to maintain top predator populations. Across their range, tiger (Panthera tigris) populations occur in small fragmented patches of habitat, often isolated by large distances in human-dominated landscapes. We assessed connectivity between 16 protected areas (PAs) in central India, a global priority landscape for tiger conservation, using data on land use and land cover, human population density, and transportation infrastructure. We identified and prioritized movement routes using a combination of least-cost corridor modeling and circuit theory. Our analyses suggest that there are several opportunities to maintain connectivity in this landscape. We mapped a total of thirty-five linkages in the region and calculated metrics to estimate their quality and importance. The highest quality linkages as measured by the ratio of cost-weighted distance to Euclidean distance are Kanha–Phen/Bandhavgarh–SanjayGhasidas/Melghat–Satpura, and cost-weighted distance to least-cost path length are Nawegaon–Tadoba/Achanakmar–SanjayGhasidas/Kanha–Phen. We used current flow centrality to evaluate the contribution of each PA and linkage toward facilitating animal movement. Values are highest for Kanha and Pench tiger reserves, and the linkages between Kanha–Phen, Kanha–Pench, and Pench–Satpura, suggesting that these PAs and linkages play a critical role in maintaining connectivity in central India. In addition, smaller areas such as Bor, Nawegaon, and Phen have high centrality scores relative to their areas and thus may act as important stepping stones. We mapped pinch points, which are sections of the linkages where tiger movement is restricted due to unfavorable habitat, transportation networks, human habitation, or a combination of factors. Currently, very limited data exist on tiger movement outside of PAs to validate model results. Regional-scale connectivity mapping efforts can assist managers and policy makers to develop strategic plans for balancing wildlife conservation and other land uses in the landscape.

Connecting the dots: mapping habitat connectivity for tigers in central India

Although significantly more money is spent on the conservation of tigers than on any other threatened species, today only 3200 to 3600 tigers roam the forests of Asia, occupying only 7% of their historical range. Despite the global significance of and interest in tiger conservation, global approaches to plan tiger recovery are partly impeded by the lack of a consensus on the number of tiger subspecies or management units, because a comprehensive analysis of tiger variation is lacking. We analyzed variation among all nine putative tiger subspecies, using extensive data sets of several traits [morphological (craniodental and pelage), ecological, molecular]. Our analyses revealed little variation and large overlaps in each trait among putative subspecies, and molecular data showed extremely low diversity because of a severe Late Pleistocene population decline. Our results support recognition of only two subspecies: the Sunda tiger, Panthera tigris sondaica, and the continental tiger, Panthera tigris tigris, which consists of two (northern and southern) management units. Conservation management programs, such as captive breeding, reintroduction initiatives, or trans-boundary projects, rely on a durable, consistent characterization of subspecies as taxonomic units, defined by robust multiple lines of scientific evidence rather than single traits or ad hoc descriptions of one or few specimens. Our multiple-trait data set supports a fundamental rethinking of the conventional tiger taxonomy paradigm, which will have profound implications for the management of in situ and ex situ tiger populations and boost conservation efforts by facilitating a pragmatic approach to tiger conservation management worldwide.

https://advances.sciencemag.org/content/advances/1/5/e1400175.full.pdf

Planning tiger recovery: Understanding intraspecific variation for effective conservation

Can forest fragmentation and configuration work as indicators of human–wildlife conflict? Evidences from human death and injury by wildlife attacks in Nepal

Living on the edge: Opportunities for Amur tiger recovery in China

https://www.cfc.umt.edu/research/heblab/files/BC_AmurTigerHabitat_2014.pdf

Including biotic interactions with ungulate prey and humans improves habitat conservation modeling for endangered Amur tigers in the Russian Far East

Tigers are globally endangered and continue to decline due to poaching, prey depletion and habitat loss. In Nepal, tiger populations are fragmented and found mainly in four protected areas (PAs). To establish the use of standard methods, to assess the importance of prey availability and human disturbance on tiger presence and to assess tiger occupancy both inside and outside PAs, we conducted a tiger occupancy survey throughout the Terai Arc Landscape of Nepal. Our model-average estimate of the probability of tiger site occupancy was 0.366 [standard error (se) = 0.02, a 7% increase from the naive estimate] and the probability of detection estimate was 0.65 (se = 0.08) per 1 km searched. Modeled tiger site occupancy ranged from 0.04 (se = 0.05) in areas with a relatively lower prey base and higher human disturbance to 1 (se = 0 and 0.14) in areas with a higher prey base and lower human disturbance. We estimated tigers occupied just 5049 (se = 3) km2 (36%) of 13 915 km2 potential tiger habitat (forests and grasslands), and we detected sign in four of five key corridors linking PAs across Nepal and India, respectively indicating significant unoccupied areas likely suitable for tigers and substantial potential for tiger dispersal. To increase tiger populations and to promote long-term persistence in Nepal, otherwise suitable areas should be managed to increase prey and minimize human disturbance especially in critical corridors linking core tiger populations.

B. Long

Papers

Influence of prey depletion and human disturbance on tiger occupancy in Nepal