Ranging,Activity and Habitat Use by Tigers in the Mangrove Forests of the Sundarban

The Sundarban of India and Bangladesh (about 6000 km²) are the only mangrove forests inhabited by a sizeable population of tigers. The adjoining area also supports one of the highest human densities and experiences severe human-tiger conflicts. We used GPS-Satellite and VHF radio-collars on 6 (3 males and 3 female) tigers to study their ranging patterns and habitat preference. The average home range (95% Fixed Kernel) for resident females was 56.4 (SE 5.69) and for males it was 110 (SE 49) km². Tigers crossed an average of 5 water channels > 30 meters per day with a mean width of 54 meters, whereas channels larger than 400 meters were rarely crossed. Tigers spent over 58% of their time within Phoenix habitat but compositional analysis showed a habitat preference of the order Avicennia-Sonneratia > Phoenix > Ceriops > Barren > Water. Average daily distance moved was 4.6 km (range 0.1–23). Activity of tigers peaked between 05:00 hours and 10:00 hours showing some overlap with human activity. Territory boundaries were demarcated by large channels which tigers intensively patrolled. Extra caution should be taken while fishing or honey collection during early morning in Avicennia-Sonneratia and Phoenix habitat types along wide channels to reduce human-tiger conflict. Considering home-range core areas as exclusive, tiger density was estimated at 4.6 (SE range 3.6 to 6.7) tigers/100 km² giving a total population of 76 (SE range 59–110) tigers in the Indian Sundarban. Reluctance of tigers to cross wide water channels combined with increasing commercial boat traffic and sea level rise due to climate change pose a real threat of fragmenting the Sundarban tiger population.     

Estimating abundance with sparse data: tigers in northern Myanmar

As part of a national strategy for recovering tiger populations, the Myanmar Government recently proposed its first and the world’s largest tiger reserve in the Hukaung Valley, Kachin State. During November 2002–June 2004, camera-traps were used to record tigers, identify individuals, and, using capture–recapture approaches, estimate density in the reserve. Despite extensive (203 trap locations, 275–558 km² sample plots) and intensive (>4,500 trap nights, 9 months of sampling) survey efforts, only 12 independent detections of six individual tigers were made across three study sites. Due to the sparse data, estimates of tiger abundance generated by Program CAPTURE could not be made for all survey sites. Other approaches to estimating density, based on numbers of tigers caught, or derived from borrowed estimates of detection probability, offer an alternative to capture–recapture analysis. Tiger densities fall in the range of 0.2–2.2 tigers/100 km², with 7–71 tigers inside a 3,250 km² area of prime tiger habitat, where efforts to protect tigers are currently focused. Tiger numbers might be stabilized if strict measures are taken to protect tigers and their prey from seasonal hunting and to suppress illegal trade in wildlife. Efforts to monitor abundance trends in the tiger population will be expensive given the difficulty with which tiger data can be obtained and the lack of available surrogate indices of tiger density. Monitoring occupancy patterns, the subject of a separate ongoing study, may be more efficient.     

Density of tiger and leopard in a tropical deciduous forest of Mudumalai Tiger Reserve,southern India,as estimated using photographic capture–recapture sampling

Density of tiger Panthera tigris and leopard Panthera pardus was estimated using photographic capture–recapture sampling in a tropical deciduous forest of Mudumalai Tiger Reserve, southern India, from November 2008 to February 2009. A total of 2,000 camera trap nights for 100 days yielded 19 tigers and 29 leopards within an intensive sampling area of 107 km². Population size of tiger from closed population estimator model M_b Zippin was 19 tigers (SE = ±0.9) and for leopards M_h Jackknife estimated 53 (SE = ±11) individuals. Spatially explicit maximum likelihood and Bayesian model estimates were 8.31 (SE = ±2.73) and 8.9 (SE = ±2.56) per 100 km² for tigers and 13.17 (SE = ±3.15) and 13.01 (SE = ±2.31) per 100 km² for leopards, respectively. Tiger density for MMDM models ranged from 6.07 (SE = ±1.74) to 9.72 (SE = ±2.94) per 100 km² and leopard density ranged from 13.41 (SE = ±2.67) to 28.91 (SE = ±7.22) per 100 km². Spatially explicit models were more appropriate as they handle information at capture locations in a more specific manner than some generalizations assumed in the classical approach. Results revealed high density of tiger and leopard in Mudumalai which is unusual for other high density tiger areas. The tiger population in Mudumalai is a part of the largest population at present in India and a source for the surrounding Reserved Forest.     

Responses of tiger (<Emphasis Type="Italic">Panthera tigris</Emphasis>) and their prey to removal of anthropogenic influences in Rajaji National Park,India

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/km², 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 of tigers (from three to five tigers per 100 km²), 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.     

Prey and tigers on the forgotten trail: high prey occupancy and tiger habitat use reveal the importance of the understudied Churia habitat of Nepal

Tigers are globally threatened and their conservation relies on intact habitat that supports key large prey. The Churia habitat is relatively unknown even though it occupies a significant portion of the forested landscape of the Terai Arc, which stretches over 1000 km in a narrow band across Nepal and India, parallel to the Himalayas. To address this lack of detailed information relevant to tiger conservation, we used sign surveys to estimate occupancy probability for 5 focal prey species of tigers (gaur, sambar, chital, wild pig, and barking deer), and assess tiger habitat use within 537 km² of the understudied Churia habitat in Chitwan National Park (CNP), Nepal. Multi-season occupancy models allowed us to make seasonal (winter vs. summer) inferences regarding changes in occupancy or habitat use based on covariates influencing occupancy and detection. We found that sambar had the largest spatial distribution occupying 431–437 km², while chital had the smallest at 100–158 km² across both seasons. The gaur population showed the most seasonal variation occupying from 413 to 318 km², suggesting their migration out of the Churia in summer and moving in during winter. Wild pigs showed the opposite trend occupying from 444 to 383 km²; suggesting moving into Churia in summer and out in winter. Barking deer were widespread in both seasons (329–349 km²). Tiger habitat use (\({{\hat{\varPsi } }}({\text{SE}})\)) was higher in winter 0.63 (0.11) than in summer 0.54 (0.21), but confidence intervals overlapped and area used was similar across seasons, 337 km² (winter) to 291 km² (summer). Available habitat, distribution of water sources, and human disturbance were the most common variables influencing spatial distribution of prey and habitat use of tigers at different spatial scales. Overall, we found high prey occupancy and tiger habitat use, suggesting the Churia is valuable habitat for ungulates and tigers. Given that this habitat accounts for 639 km² within CNP and 7642 km² across the entire Terai Arc, the Churia should no longer be neglected in global tiger conservation planning.     

Tiger straying incidents in Indian Sundarban: statistical analysis of case studies as well as depredation caused by conflict

The Sundarban of India and Bangladesh is the only mangrove reserve forest in the world inhabited by the tiger (Panthera tigris). Tigers in the Sundarban mangrove are widely known for frequently straying into the surrounding reclaimed areas. Data collected from household village survey and documents of the Forest Department show that tiger straying incidents happen throughout the year, but most of them occurred during 3 months (Dec–Feb) of the winter season (42%) followed by 3 months (July–Sept) of the monsoon season (31%). 84.22% of cases have been reported from 21 villages of five affected blocks of Sundarban. In most cases, tigers resorted to cattle lifting or poultry feeding. Only in 8.9% of the cases were human beings attacked or killed. Majority of the straying tigers (68.46%) were male. In most cases (78.9%) strayed tigers were aged and 22% of these were partly injured. 96.05% straying occurs during night. This study also aims at exploring the causes of frequent straying, livestock and human casualties as a result of conflict and retaliation killing of tigers. Straying frequency is correlated negatively with the width of the creeks or rivers in the village side and no relationship is identified with the area of the forest block as well as natural prey abundance. Overall, improved nylon fencing, increased patroling, establishment of the Forest Protection Committee (FPC) and the Eco Development Committee (EDC) are not associated with reduction of straying frequency as well as livestock losses to tiger straying.     

Effects of environmental and anthropogenic drivers on Amur tiger distribution in northeastern China

We examined environmental and anthropogenic factors drive range loss in large mammals, using presence data of Amur tigers opportunistically collected between 2000 and 2012, and anthropogenic and environmental variables to model the distribution of the Amur tiger in northeastern China. Our results suggested that population distribution models of different subregions showed different habitat factors determining tiger population distribution patterns. Where farmland cover was over 50 km² per pixel (196 km²), distance was within 15 km to the railway in Changbaishan and road density (length per pixel) increased in Wandashan, the relative probability of Amur tiger occurrence exhibited monotonic avoidance responses; however, where distance was within 150 km of the Sino-Russia border, the occurrence probability of Amur tiger was relatively high. We analyzed the avoidance or preference responses of Amur tiger distribution to elevation, snow depth and Viewshed. Furthermore, different subregional models detected a variety of spatial autocorrelation distances due to different population clustering patterns. We found that spatial models significantly improved model fits for non-spatial models and made more robust habitat suitability predications than that of non-spatial models. Consequently, these findings provide useful guidance for habitat conservation and management.     

Impact of prey occupancy and other ecological and anthropogenic factors on tiger distribution in Thailand's western forest complex

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Integrating sign surveys and telemetry data for estimating brown bear (Ursus arctos) density in the Romanian Carpathians

Accurate population size estimates are important information for sustainable wildlife management. The Romanian Carpathians harbor the largest brown bear (Ursus arctos) population in Europe, yet current management relies on estimates of density that lack statistical oversight and ignore uncertainty deriving from track surveys. In this study, we investigate an alternative approach to estimate brown bear density using sign surveys along transects within a novel integration of occupancy models and home range methods. We performed repeated surveys along 2‐km segments of forest roads during three distinct seasons: spring 2011, fall‐winter 2011, and spring 2012, within three game management units and a Natura 2000 site. We estimated bears abundances along transects using the number of unique tracks observed per survey occasion via N‐mixture hierarchical models, which account for imperfect detection. To obtain brown bear densities, we combined these abundances with the effective sampling area of the transects, that is, estimated as a function of the median (± bootstrapped SE) of the core home range (5.58 ± 1.08 km²) based on telemetry data from 17 bears tracked for 1‐month periods overlapping our surveys windows. Our analyses yielded average brown bear densities (and 95% confidence intervals) for the three seasons of: 11.5 (7.8–15.3), 11.3 (7.4–15.2), and 12.4 (8.6–16.3) individuals/100 km². Across game management units, mean densities ranged between 7.5 and 14.8 individuals/100 km². Our method incorporates multiple sources of uncertainty (e.g., effective sampling area, imperfect detection) to estimate brown bear density, but the inference fundamentally relies on unmarked individuals only. While useful as a temporary approach to monitor brown bears, we urge implementing DNA capture–recapture methods regionally to inform brown bear management and recommend increasing resources for GPS collars to improve estimates of effective sampling area.     

Monitoring tiger populations using intensive search in a capture–recapture framework

Tigers (Panthera tigris) today face multiple threats to their survival in the form of habitat loss, poaching, depletion of wild prey through illegal hunting and loss of connectivity between populations. Monitoring of tigers is crucial to evaluate their status and react adaptively to management problems. Though camera traps are becoming increasingly popular with researchers enumerating cryptic and elusive animals, they have not been embedded in the regular management activities of tiger reserves. Tiger monitoring, though an important part of the management, is usually implemented using the unreliable pugmark approach. Camera trap-based studies are few, usually of short duration, and are generally conducted by individual scientists and organizations. In this study, we integrate photographic mark–recapture with the routine activity of searching and locating tigers for tourist viewing by the park management in meadows of Kanha Tiger Reserve which form a part of the tourism zone. We validate the density estimates from “tiger search approach” against those obtained from camera trapping and radio-telemetry conducted in conjunction in the same area. Tiger density (\( \hat{D} \) (SE [\( \hat{D} \)]) per 100 km² for camera traps and tiger search, respectively, was estimated at 12.0 (1.95) and 12.0 (1.76) when effective trapping area was estimated using the half mean maximum distance moved (½ MMDM), 7.6 (1.94) and 7.5 (1.97) using the home range radius, 7.3 (1.49) and 7.5 (1.97) with the full MMDM, and 8.0 (3.0) and 6.88 (2.39) with the spatial likelihood method in Program DENSITY 4.1. Camera trapping, however, was five times more expensive than the tiger search method. Our study suggests that “tiger search approach” can be used as a regular monitoring tool in the tourism zones of tiger reserves, where often most of the source populations are located.     

Trio under threat: can we secure the future of rhinos,elephants and tigers in Malaysia?

Three of Malaysia’s endangered large mammal species are experiencing contrasting futures. Populations of the Sumatran rhino (Dicerorhinus sumatrensis) have dwindled to critically low numbers in Peninsular Malaysia (current estimates need to be revised) and the state of Sabah (less than 40 individuals estimated). In the latter region, a bold intervention involving the translocation of isolated rhinos is being developed to concentrate them into a protected area to improve reproduction success rates. For the Asian elephant (Elephas maximus), recently established baselines for Peninsular Malaysia (0.09 elephants/km² estimated from one site) and Sabah (between 0.56 and 2.15 elephants/km² estimated from four sites) seem to indicate globally significant populations based on dung count surveys. Similar surveys are required to monitor elephant population trends at these sites and to determine baselines elsewhere. The population status of the Malayan tiger (Panthera tigris jacksoni) in Peninsular Malaysia, however, remains uncertain as only a couple of scientifically defensible camera-trapping surveys (1.66 and 2.59 tigers/100 km² estimated from two sites) have been conducted to date. As conservation resources are limited, it may be prudent to focus tiger monitoring and protection efforts in priority areas identified by the National Tiger Action Plan for Malaysia. Apart from reviewing the conservation status of rhinos, elephants and tigers and threats facing them, we highlight existing and novel conservation initiatives, policies and frameworks that can help secure the long-term future of these iconic species in Malaysia.     

Hyper‐abundance of Native Wild Pigs (Sus scrofa) in a Lowland Dipterocarp Rain Forest of Peninsular Malaysia1

This study reports extraordinarily high density estimates for the wild pig (Sus scrofa) from an aseasonal tropical forest site within the species'native range. At Pasoh Forest Reserve, a 2500 ha area of lowland dipterocarp rain forest in Peninsular Malaysia, line transects were used to estimate pig density from May to October in 1996 and 1998. In 1996, 44 sightings of S. scrofa consisting of 166 individuals were recorded along 81 km of transects. In 1998, 39 sightings documented 129 individuals along 79.9 km of transects. Estimated population density was 47.0 pigs/km² in 1996 and 27.0 pigs/km²‐ in 1998. Sus scrofa biomass in this forest was estimated at 1837 kg/km² and 1346 kg/ km² in 1996 and 1998, respectively. Differences between years were attributed to changes in the density of young pigs, coincident with a mast‐seeding year of dipterocarp trees in 1996. Pig densities at Pasoh Forest Reserve were much higher than at other forest locations within the species' native range in Europe and Asia. Because Pasoh Forest Reserve is a forest fragment, two factors likely account for the extremely high pig densities: (1) local extinction of natural predators (mainly tigers and leopards) and (2) an abundant year‐round food supply of African oil palm fruits from extensive plantations bordering the reserve.     

Genetic mark–recapture population estimation in black bears and issues of scale

Abundance estimates for black bears (Ursus americanus) are important for effective management. Recently, DNA technology has resulted in widespread use of noninvasive, genetic capture–mark–recapture (CMR) approaches to estimate populations. Few studies have compared the genetic CMR methods to other estimation methods. We used genetic CMR to estimate the bear population at 2 study sites in northern New Hampshire (Pittsburg and Milan) in 2 consecutive years. We compared these estimates to those derived from traditional methods used by the New Hampshire Fish and Game Department (NHFG) using hunter harvest and mortality data. Density estimates produced with genetic CMR methods were similar both years and were comparable to those derived from traditional methods. In 2006, the estimated number of bears in Pittsburg was 79 (95% CI = 60–98) corresponding to a density of 15–24 (95% CI) bears/100 km²; the 2007 estimate was 83 (95% CI = 67–99; density = 16–24 bears/100 km²). In 2006, the estimated number of bears in Milan was 95 (95% CI = 74–117; density = 16–25 bears/100 km²); the 2007 estimate was 96 (95% CI = 77–114; density = 17–25 bears/100 km²). We found that genetic CMR methods were able to identify demographic variation at a local scale, including a strongly skewed sex ratio (2 M:1 F) in the Milan population. Genetic CMR is a useful tool for wildlife managers to monitor populations of local concern, where abundance or demographic characteristics may deviate from regional estimates. Future monitoring of the Milan population with genetic CMR is recommended to determine if the sex ratio bias continues, possibly warranting a change in local harvest regimes. © 2011 The Wildlife Society.     

Leopard density in post-conflict landscape,Cambodia: Evidence from spatially explicit capture–recapture

Effective conservation of large carnivores requires reliable estimates of population density, often obtained through capture–recapture analysis, in order to prioritize investments and assess conservation intervention effectiveness. Recent statistical advances and development of user-friendly software for spatially explicit capture–recapture (SECR) circumvent the difficulties in estimating effective survey area, and hence density, from capture–recapture data. We conducted a camera-trapping study on leopards (Panthera pardus) in Mondulkiri Protected Forest, Cambodia. We compared density estimates using SECR with those obtained from conventional approaches in which the effective survey area is estimated using a boundary strip width based on observed animal movements. Density estimates from Chao heterogeneity models (3.8 ± SE 1.9 individuals/100 km²) and Pledger heterogeneity models and models accounting for gender-specific capture and recapture rates (model-averaged density 3.9 ± SE 2.9 individuals/100 km²) were similar to those from SECR in program DENSITY (3.6 ± SE 1.0/100 km²) but higher than estimates from Jack-knife heterogeneity models (2.9 ± SE 0.9 individuals/100 km²). Capture probabilities differed between male and female leopards probably resulting from differences in the use of human-made trails between sexes. Given that there are a number of biologically plausible reasons to expect gender-specific variation in capture probabilities of large carnivores, we recommend exploratory analysis of data using models in which gender can be included as a covariate affecting capture probabilities particularly given the demographic importance of breeding females for population recovery of threatened carnivores. © 2011 The Wildlife Society.     

黑龙江省东完达山地区东北虎猎物种群现状及动态趋势

猎物种群丰度是限制虎分布和数量的关键因子,因此猎物种群密度监测和估算是虎保护的重要内容之一。应用采用大样方法,地理信息系统技术和多元统计分析,研究了黑龙江东完达山东部地区东北虎猎物种群(马鹿、狍子和野猪)现状及动态变化趋势。结果表明:研究地区马鹿的种群平均密度为(0.2010±0.0270)只/km²、狍子的平均种群密度为(0.4980±0.0436)只/km²、野猪的平均种群密度为(0.3423±0.0275)只/km²。单因素方差分析表明,在相同生境下,3种有蹄类密度在在阔叶混交林中和杂木林中差异极为显著;不同的生境,3种猎物的猎物的密度也存在着显著差异。相关分析表明马鹿密度和野猪密度程正相关,而马鹿密度和狍子密度、狍子密度和野猪密度则不相关。 同1989年该地区东北虎猎物种群相比:1989-2002年的13 a时间内马鹿的年平均递减率为13.48%、狍子的年平均递减率为12.69%、野猪的年平均递减率为1.89%。     

Population density and abundance of sympatric large carnivores in the lowland tropical evergreen forest of Indian Eastern Himalayas

Low density occurrence of large carnivore species and direct hunting of predators and prey make carnivore conservation complex. Vital baseline information on population status of large carnivores is still deficient in most forests of eastern Himalaya, which are known to be the biodiversity hotspots. To fill this information gap, we estimated the large carnivore population status and abundance in an intricate eastern Himalayan lowland tropical forest in Pakke Tiger Reserve, Arunachal Pradesh. Population status and abundance estimates of tigers and leopards were made through individual identification using closed capture-recapture sampling. To estimate the dhole abundance photographic encounter rate was used. For individually non-identifiable species photographic rate seemed to correlate well with animal abundance. The estimated tiger and leopard density through 1/2 MMDM was 2.14 ± 0.04/100 km² and 2.99 ± 1.13/100 km² respectively. Maximum likelihood estimates shows density of tiger 1.86 ± 0.7 and for leopard 2.82 ± 1.2.The estimated dhole abundance was (N) 10.6 ± 0.94, and density 6.62 ± 0.58 individuals in 100 km². Further, occupancy estimation of large carnivores may be tried along with assessing the comparative efficacy of other population estimation methods to establish better monitoring methods for this region.     

Population densities,group size and biomass of ungulates in a lowland tropical rainforest forest of the eastern Himalayas

Large ungulate population monitoring is a crucial wildlife management tool as ungulates help in structuring and maintaining the large carnivore populations. Reliable data on population status of major ungulate prey species are still non-existent for most of the protected areas in the Indian part of the eastern Himalayan biodiversity hotspot. Twenty transects were monitored over a period of three years (2009–2011) totaling 600 km with an average length of 2 km. The estimated mean density of ungulates was 17.5 km⁻² with overall density of 48.7 km⁻². The wild pig Sus scrofa had the highest density (6.7 ± 1.2 km⁻²) among all the prey species followed by barking deer Muntiacus muntjak (3.9 ± 0.6 km⁻²), sambar Rusa unicolor (3.8 ± 0.5) and gaur Bos gaurus (3.5 ± 0.9 km⁻²). The estimated total ungulate biomass density was 2182.56 kg km⁻². This prey biomass can support up to 7.2 tigers per 100 km⁻². However, with two other sympatric carnivores sharing the same resources, the actual tiger numbers that can be supported will be lower. The estimated minor prey species was 31 km⁻² significantly 30.6% crop damages were reported by wild pig (p = 0.01) and 35.4% was elephant (p = 0.004). This data on ungulate densities and biomass will be crucial for carnivore conservation in this understudied globally significant biodiversity hotspot.     

Long-term monitoring of a Bengal tiger (<Emphasis Type="Italic">Panthera tigris tigris</Emphasis>) population in a human-dominated landscape of Central India

Long-term monitoring of tiger population is essential in any human-dominated landscape as globally their population is showing a declining trend due to unrelenting stress or stochastic events. In view of that, Bengal tiger population was monitored in Pench Tiger Reserve (Pench), Madhya Pradesh of Central India between May 2006 and April 2013. The population, age-sex ratios, survival rate, growth rate, and recruitment pattern of adult (≥36 month), subadult (≥18 to 36 month), and cubs (≤15 month) were studied using camera trap and radio-telemetry techniques. Overall, tiger density ± SE/100 km² using Maximum Likelihood Spatial Explicit Capture Recapture method was 5.5 ± 1.6 in first trapping period or year and 3.7 ± 0.8 in last or seventh trapping year. The estimated survival rate of all tiger (n = 66) was 0.66 (±0.04), whereas mean annual growth rate (±SE) was 1.15 (±0.11) i.e. 15%. The sex ratio (male/female) found to be female biased and more than 80% of overall recruitment was contributed by female tiger. The dispersal of subadults in the tiger population contributed gradual fluctuation in survival rate and annual growth rate, as resident adult tiger population remained almost stable over the study period. As the overall tigers are surviving in a small population size and operating at carrying capacity, the important corridors connecting with neighboring population of Kanha Tiger Reserve and Satpura Tiger Reserve may ensure constant emigration and immigration to reduce the chances of genetic drift or inbreeding in the Pench tiger population.     

Philopatry and Dispersal Patterns in Tiger (Panthera tigris)

Background

Tiger populations are dwindling rapidly making it increasingly difficult to study their dispersal and mating behaviour in the wild, more so tiger being a secretive and solitary carnivore.

Methods

We used non-invasively obtained genetic data to establish the presence of 28 tigers, 22 females and 6 males, within the core area of Pench tiger reserve, Madhya Pradesh. This data was evaluated along with spatial autocorrelation and relatedness analyses to understand patterns of dispersal and philopatry in tigers within this well-managed and healthy tiger habitat in India.

Results

We established male-biased dispersal and female philopatry in tigers and reiterated this finding with multiple analyses. Females show positive correlation up to 7 kms (which corresponds to an area of approximately 160 km²) however this correlation is significantly positive only upto 4 kms, or 50 km² (r  = 0.129, p<0.0125). Males do not exhibit any significant correlation in any of the distance classes within the forest (upto 300 km²). We also show evidence of female dispersal upto 26 kms in this landscape.

Conclusions

Animal movements are important for fitness, reproductive success, genetic diversity and gene exchange among populations. In light of the current endangered status of tigers in the world, this study will help us understand tiger behavior and movement. Our findings also have important implications for better management of habitats and interconnecting corridors to save this charismatic species.     

Influence of connectivity, wild prey and disturbance on occupancy of tigers in the human-dominated western Terai Arc Landscape

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.