Assessment of fine-scale resource selection and spatially explicit habitat suitability modelling for a re-introduced tiger (Panthera tigris) population in central India

Background Large carnivores influence ecosystem functions at various scales. Thus, their local extinction is not only a species-specific conservation concern, but also reflects on the overall habitat quality and ecosystem value. Species-habitat relationships at fine scale reflect the individuals’ ability to procure resources and negotiate intraspecific competition. Such fine scale habitat choices are more pronounced in large carnivores such as tiger (Panthera tigris), which exhibits competitive exclusion in habitat and mate selection strategies. Although landscape level policies and conservation strategies are increasingly promoted for tiger conservation, specific management interventions require knowledge of the habitat correlates at fine scale. Methods We studied nine radio-collared individuals of a successfully reintroduced tiger population in Panna Tiger Reserve, central India, focussing on the species-habitat relationship at fine scales. With 16 eco-geographical variables, we performed Manly’s selection ratio and K-select analyses to define population-level and individual-level variation in resource selection, respectively. We analysed the data obtained during the exploratory period of six tigers and during the settled period of eight tigers separately, and compared the consequent results. We further used the settled period characteristics to model and map habitat suitability based on the Mahalanobis D2 method and the Boyce index. Results There was a clear difference in habitat selection by tigers between the exploratory and the settled period. During the exploratory period, tigers selected dense canopy and bamboo forests, but also spent time near villages and relocated village sites. However, settled tigers predominantly selected bamboo forests in complex terrain, riverine forests and teak-mixed forest, and totally avoided human settlements and agriculture areas. There were individual variations in habitat selection between exploratory and settled periods. Based on threshold limits of habitat selection by the Boyce Index, we established that 83% of core and 47% of buffer areas are now suitable habitats for tiger in this reserve. Discussion Tiger management often focuses on large-scale measures, but this study for the first time highlights the behaviour and fine-scale individual-specific habitat selection strategies. Such knowledge is vital for management of critical tiger habitats and specifically for the success of reintroduction programs. Our spatially explicit habitat suitability map provides a baseline for conservation planning and optimizing carrying capacity of the tiger population in this reserve.

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Human-induced changes in habitat preference by capybaras (Hydrochoerus hydrochaeris) and their potential effect on zoonotic disease transmission

10.1101/2020.02.05.935445 ◽

2020 ◽

Author(s):

Thiago C. Dias ◽

Jared A. Stabach ◽

Qiongyu Huang ◽

Marcelo B. Labruna ◽

Peter Leimgruber ◽

...

Keyword(s):

Habitat Selection ◽

Disease Transmission ◽

Resource Selection ◽

Spotted Fever ◽

Space Use ◽

Zoonotic Disease ◽

Disease Spread ◽

Selection Strategies ◽

Hydrochoerus Hydrochaeris ◽

Natural Landscapes

AbstractHuman activities are changing landscape structure and function globally, affecting wildlife space use, and ultimately increasing human-wildlife conflicts and zoonotic disease spread. Capybara (Hydrochoerus hydrochaeris) is a conflict species that has been implicated in the spread and amplification of the most lethal tick-borne disease in the world, the Brazilian spotted fever (BSF). Even though essential to understand the link between capybaras, ticks and the BSF, many knowledge gaps still exist regarding the effects of human disturbance in capybara space use. Here, we analyzed diurnal and nocturnal habitat selection strategies of capybaras across natural and human-modified landscapes using resource selection functions (RSF). Selection for forested habitats was high across human- modified landscapes, mainly during day- periods. Across natural landscapes, capybaras avoided forests during both day- and night periods. Water was consistently selected across both landscapes, during day- and nighttime. This variable was also the most important in predicting capybara habitat selection across natural landscapes. Capybaras showed slightly higher preferences for areas near grasses/shrubs across natural landscapes, and this variable was the most important in predicting capybara habitat selection across human-modified landscapes. Our results demonstrate human-driven variation in habitat selection strategies by capybaras. This behavioral adjustment across human-modified landscapes may be related to BSF epidemiology.

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Optimization of spatial scale, but not functional shape, affects the performance of habitat suitability models: a case study of tigers (Panthera tigris) in Thailand

Landscape Ecology ◽

10.1007/s10980-020-01105-6 ◽

2021 ◽

Vol 36 (2) ◽

pp. 455-474

Author(s):

Eric Ash ◽

David W. Macdonald ◽

Samuel A. Cushman ◽

Adisorn Noochdumrong ◽

Tim Redford ◽

...

Keyword(s):

Habitat Selection ◽

Habitat Suitability ◽

Environmental Variables ◽

Spatial Scales ◽

Model Performance ◽

Panthera Tigris ◽

Habitat Suitability Models ◽

Multi Scale ◽

Single Scale ◽

Optimized Model

Abstract Context Species habitat suitability models rarely incorporate multiple spatial scales or functional shapes of a species’ response to covariates. Optimizing models for these factors may produce more robust, reliable, and informative habitat suitability models, which can be beneficial for the conservation of rare and endangered species, such as tigers (Panthera tigris). Objectives We provide the first formal assessment of the relative impacts of scale-optimization and shape-optimization on model performance and habitat suitability predictions. We explored how optimization influences conclusions regarding habitat selection and mapped probability of occurrence. Methods We collated environmental variables expected to affect tiger occurrence, calculating focal statistics and landscape metrics at spatial scales ranging from 250 m to 16 km. We then constructed a set of presence–absence generalized linear models including: (1) single-scale optimized models (SSO); (2) a multi-scale optimized model (MSO); (3) single-scale shape-optimized models (SSSO) and (4) a multi-scale- and shape-optimized model (MSSO). We compared performance and resulting prediction maps for top performing models. Results The SSO (16 km), SSSO (16 km), MSO, and MSSO models performed equally well (AUC > 0.9). However, these differed substantially in prediction and mapped habitat suitability, leading to different ecological understanding and potentially divergent conservation recommendations. Habitat selection was highly scale-dependent and the strongest relationships with environmental variables were at the broadest scales analysed. Modelling approach had a substantial influence in variable importance among top models. Conclusions Our results suggest that optimization of the scale of resource selection is crucial in modelling tiger habitat selection. However, in this analysis, shape-optimization did not improve model performance.

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Density estimation of tiger and leopard using spatially explicit capture–recapture framework

PeerJ ◽

10.7717/peerj.10634 ◽

2021 ◽

Vol 9 ◽

pp. e10634

Author(s):

Tahir Ali Rather ◽

Sharad Kumar ◽

Jamal Ahmad Khan

Keyword(s):

Protected Areas ◽

Management Strategies ◽

Natural Vegetation ◽

Camera Traps ◽

Spatially Explicit ◽

Panthera Tigris ◽

Large Carnivores ◽

Road Density ◽

Buffer Zones ◽

Capture Recapture

The conservation of large carnivores often requires precise and accurate estimates of their populations. Being cryptic and occurring at low population densities, obtaining an unbiased population estimate is difficult in large carnivores. To overcome the uncertainties in the conventional capture–recapture (CR) methods used to estimate large carnivore densities, more robust methods such as spatially explicit capture-recapture (SECR) framework are now widely used. We modeled the CR data of tiger (Panthera tigris tigris) and leopard (Panthera pardus fusca) in the SECR framework with biotic and abiotic covariates likely believed to influence their densities. An effort of 2,211 trap nights resulted in the capture of 33 and 38 individual tigers and leopards. A total of 95 and 74 detections of tigers and leopards were achieved using 35 pairs of camera traps. Tiger and leopard density were estimated at 4.71 ± 1.20 (3.05–5.11) and 3.03 ± 0.78 (1.85–4.99) per 100 km2. Our results show that leopard density increased with high road density, high terrain ruggedness and habitats with high percentage of cropland and natural vegetation. The tiger density was positively influenced by the mosaic of cropland and natural vegetation. This study provides the first robust density estimates of tiger and leopard within the study area. Our results support the notion that large carnivores can attain moderate densities within human-dominated regions around protected areas relying on domestic livestock. Broader management strategies aimed at maintaining wild prey in the human-dominated areas around protected areas are necessary for large and endangered carnivores’ sustenance in the buffer zones around protected areas.

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Large carnivore attacks on humans in central India: a case study from the Tadoba-Andhari Tiger Reserve

Oryx ◽

10.1017/s0030605311001803 ◽

2013 ◽

Vol 47 (2) ◽

pp. 221-227 ◽

Cited By ~ 25

Author(s):

Harshawardhan S. Dhanwatey ◽

Joanne C. Crawford ◽

Leandro A. S. Abade ◽

Poonam H. Dhanwatey ◽

Clayton K. Nielsen ◽

...

Keyword(s):

Central India ◽

Forest Products ◽

Timber Harvesting ◽

Panthera Tigris ◽

Large Carnivores ◽

Panthera Pardus ◽

Large Carnivore ◽

Tiger Reserve ◽

North Eastern

AbstractWe examined human and ecological attributes of attacks by tigers Panthera tigris and leopards Panthera pardus on humans in and around the Tadoba-Andhari Tiger Reserve in the Chandrapur District of central India to provide recommendations to prevent or mitigate conflicts between people and large carnivores. During 2005–2011 132 carnivore attacks on humans occurred, 71 (54%) of which were lethal to humans. Tigers and leopards were responsible for 78% and 22% of attacks, respectively. Significantly more victims were attacked while collecting minor forest products than during other activities. Probability of attack significantly decreased with increasing distance from forests and villages, and attacks occurred most frequently in the forested north-eastern corridor of the study area. Human activities near the Reserve need to be regulated and limited as much as possible to reduce human mortality and other conflicts. Increasing access to alternative fuel sources (e.g. biogas, solar) may reduce the pressure of timber harvesting on protected areas. Residents should be trained in identifying carnivore sign and in ways to reduce their vulnerability when working outdoors.

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Forest corridors maintain historical gene flow in a tiger metapopulation in the highlands of central India

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2013.1506 ◽

2013 ◽

Vol 280 (1767) ◽

pp. 20131506 ◽

Cited By ~ 62

Author(s):

Sandeep Sharma ◽

Trishna Dutta ◽

Jesús E. Maldonado ◽

Thomas C. Wood ◽

Hemendra Singh Panwar ◽

...

Keyword(s):

Gene Flow ◽

Central India ◽

Population History ◽

Conservation Strategies ◽

Population Subdivision ◽

Panthera Tigris ◽

Fragmented Habitat ◽

Contemporary Gene Flow ◽

Forest Corridors ◽

Tiger Population

Understanding the patterns of gene flow of an endangered species metapopulation occupying a fragmented habitat is crucial for landscape-level conservation planning and devising effective conservation strategies. Tigers ( Panthera tigris ) are globally endangered and their populations are highly fragmented and exist in a few isolated metapopulations across their range. We used multi-locus genotypic data from 273 individual tigers ( Panthera tigris tigris ) from four tiger populations of the Satpura–Maikal landscape of central India to determine whether the corridors in this landscape are functional. This 45 000 km 2 landscape contains 17% of India's tiger population and 12% of its tiger habitat. We applied Bayesian and coalescent-based analyses to estimate contemporary and historical gene flow among these populations and to infer their evolutionary history. We found that the tiger metapopulation in central India has high rates of historical and contemporary gene flow. The tests for population history reveal that tigers populated central India about 10 000 years ago. Their population subdivision began about 1000 years ago and accelerated about 200 years ago owing to habitat fragmentation, leading to four spatially separated populations. These four populations have been in migration–drift equilibrium maintained by high gene flow. We found the highest rates of contemporary gene flow in populations that are connected by forest corridors. This information is highly relevant to conservation practitioners and policy makers, because deforestation, road widening and mining are imminent threats to these corridors.

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Habitat connectivity and resource selection in an expanding bobcat (Lynx rufus) population

PeerJ ◽

10.7717/peerj.12460 ◽

2021 ◽

Vol 9 ◽

pp. e12460

Author(s):

Viorel D. Popescu ◽

Madeline Kenyon ◽

Ryan K. Brown ◽

Marissa A. Dyck ◽

Suzanne Prange ◽

...

Keyword(s):

Habitat Selection ◽

Home Range ◽

Habitat Suitability ◽

Resource Selection ◽

Population Level ◽

Habitat Connectivity ◽

Lynx Rufus ◽

Home Ranges ◽

Core Areas ◽

Selection For

Terrestrial carnivores are among the most imperiled species worldwide, yet some species are resilient and are recovering in human-dominated landscapes after decades or centuries of absence. Bobcat (Lynx rufus) populations were extirpated from much of Midwestern US in the mid-1800’s, and are currently expanding and recolonizing their former range. In this study, we investigated multi-scale habitat selection for Ohio’s expanding bobcat population, and examined habitat connectivity in order to evaluate the conduits for dispersal statewide. We used citizen observations collected between 1978 and 2019 and logistic regression to evaluate population-level habitat selection, and GPS telemetry data for 20 individuals collected between 2012 and 2014 and a distribution-weighted exponential Resource Selection Function to evaluate individual-level habitat selection within home ranges. At the population level, bobcats selected for higher amounts of forest and pasture (at a 50 km2 scale) and herbaceous vegetation (at 15–50 50 km2 scales), thus overall heterogeneous forested habitat. At individual (home range) level, bobcats selected for forested habitats with low road density and farther away from high traffic roads; they also showed weak selection for open habitat at the home range level. Male home ranges were significantly greater than female home ranges. Lastly, we used the population-level spatial outputs (i.e. habitat suitability map) to parameterize habitat connectivity models using circuit theory in the program Circuitscape. We tested three relationships between habitat suitability and resistance to movement and used a subset of data on potential dispersing individuals to evaluate which relationship performed best. All three relationships performed almost equally well, and we calculated a weighted averaged connectivity map as our final map. Habitat was highly permeable to movements between core areas of two genetically distinct subpopulations located in southeastern Ohio. We also identified potential dispersal corridors from the core areas to other regions of Ohio dominated by agriculture and suburban development via forested riparian corridors. Overall, our analysis offers new information on habitat selection and connectivity in a rebounding felid population and offers important ecological information for wildlife management strategies. We recommend that the suitability and connectivity models should be periodically updated until the population reaches an equilibrium, and be integrated with data from neighboring states for a comprehensive assessment of a conservation success story.

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