Summary1. Several conservation initiatives are aiming to improve the status of the rapidly dwindling populations of tiger Panthera tigris. However, possible cascading effects of intra-guild competition on other sympatric carnivores are rarely considered while planning such recovery programmes. 2. In this study, we examine how, following the reduction of anthropogenic pressures by relocation of pastoralists, a recovering tiger population affects leopards Panthera pardus in the Chilla Range of Rajaji National Park (RNP), India. By combining data gathered over 4 years (2004-2005 to 2007-2008) on prey availability, food habits and population density of the two predators, we investigate some of the mechanisms of niche partitioning. 3. Based on existing information, we predicted that there would be high dietary overlap between the two predators. Over time, optimal habitats would be dominated by tigers forcing leopards to the periphery of the protected area where they would subsist on small prey and domestic livestock. Consequently, leopards would occur at a lower density where sympatric with tigers. 4. Our results confirmed that annual dietary overlap (0AE89, 0AE82, 0AE78, 0AE77) between the two predators was high during the study. As expected, we observed a shift in the diet of leopards towards a significantly higher intake of domestic prey ($6AE8% to $31AE8%) and small prey ($9% to $36%). 5. Synthesis and applications. Although based on small sample sizes, our study revealed that over the 4 years following the relocation of pastoralists out of RNP, the tiger population recovered but leopard densities declined sharply. The concurrent shift in leopard diet indicated heightened livestock depredation from the surrounding area. Therefore, it is important that conservation initiatives targeting the recovery of tigers should be preceded by careful examination of interspecific interactions with sympatric carnivores. Comprehensive human-carnivore conflict management measures like monitoring the extent of livestock depredation, improving livestock management and providing adequate compensation and ⁄ or insurance schemes are critical for successfully implementing such conservation efforts.

In an unprecedented response to the rapid decline in wild tiger populations, the Heads of Government of the 13 tiger range countries endorsed the St. Petersburg Declaration in November 2010, pledging to double the wild tiger population. We conducted a landscape analysis of tiger habitat to determine if a recovery of such magnitude is possible. The reserves in 20 priority tiger landscapes can potentially support >10,000 tigers, almost thrice the current estimate. However, most core reserves where tigers breed are small and land-use change in rapidly developing Asia threatens to increase reserve and population isolation. Maintaining population viability and resilience will depend upon a landscape approach to manage tigers as metapopulations. Thus, both site-level protection and landscape-scale interventions to secure habitat corridors are simultaneous imperatives. Co-benefits, such as payment schemes for carbon and other ecosystem services, should be employed as strategies to mainstream landscape conservation in tiger habitat into development processes.

Occupying only 7% of their historical range and confined to forested habitats interspersed in a matrix of human dominated landscapes, tigers (Panthera tigris) typify the problems faced by most large carnivores worldwide. With heads of governments of tiger range countries pledging to reverse the extinction process and setting a goal of doubling wild tiger numbers by 2022, achieving this target would require identifying existing breeding cores, potential breeding habitats and opportunities for dispersal. The Terai Arc Landscape (TAL) represents one region which has recently witnessed recovery of tiger populations following conservation efforts. In this study, we develop a spatially explicit tiger occupancy model with survey data from 2009–10 based on a priori knowledge of tiger biology and specific issues plaguing the western TAL (6,979 km2), which occurs in two disjunct units (Tiger Habitat Blocks; THBs). Although the overall occupancy of tigers was 0.588 (SE 0.071), our results clearly indicate that loss in functionality of a regional corridor has resulted in tigers now occupying 17.58% of the available habitat in THB I in comparison to 88.5% in THB II. The current patterns of occupancy were best explained by models incorporating the interactive effect of habitat blocks (AIC w = 0.883) on wild prey availability (AIC w = 0.742) and anthropogenic disturbances (AIC w = 0.143). Our analysis has helped identify areas of high tiger occupancy both within and outside existing protected areas, which highlights the need for a unified control of the landscape under a single conservation unit with the primary focus of managing tigers and associated wildlife. Finally, in the light of global conservation targets and recent legislations in India, our study assumes significance as we identify opportunities to secure (e.g. THB II) and increase (e.g. THB I) tiger populations in the landscape.

Presence of human settlements in most protected areas has forced tigers (Panthera tigris) to share space with humans. Creation of inviolate space for tigers in areas with high human densities is often daunting and requires hard political sacrifices. We conducted this study from 2004 to 2007 in the Chilla range of Rajaji National Park, along the northwestern portion of the Terai-Arc Landscape in the Indian subcontinent. Our objective was to document the recovery of prey and tiger populations following the resettlement of 193 gujjar (pastoralists with large buffalo holdings) families. We used distance sampling to estimate density of wild ungulate prey and camera traps to estimate tiger density. The study area supported ∼66 ungulates/km 2 , with chital (Axis axis) and sambar (Cervus unicolor) contributing >91%. While prey densities did not vary across 3 years, an increase in proportion of chital fawns was observed following the near complete removal of livestock. We also documented an increase in the density b D of tigers (from three to five tigers per 100 km 2 ), probably due to immigrating tigers from nearby Corbett Tiger Reserve. A high turnover of individual tigers was observed during the study. With photographic evidence of breeding tigers in Chilla range, we believe that this area could serve as a source population from where tigers can colonize adjoining forests across River Ganga. It is therefore concluded that securing the connectivity between forests on the east and west bank of Ganga through the tenuous Chilla-Motichur corridor assumes significance for long-term persistence of tigers within this landscape.

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.