@article {53183, title = {Insights from distribution dynamics inform strategies to conserve a dhole Cuon alpinus metapopulation in India.}, journal = {Sci Rep}, volume = {9}, year = {2019}, month = {2019 Feb 28}, pages = {3081}, abstract = {

Most large carnivore populations currently occur in heterogeneous landscapes, with source populations embedded in a matrix of human-dominated habitats. Understanding changes in distribution of endangered carnivores is critical for prioritizing and implementing conservation strategies. We examined distribution and dynamics of a dhole Cuon alpinus metapopulation, first in 2007 and subsequently in 2015, based on indirect sign surveys across 37, 000sq. km of India{\textquoteright}s Western Ghats. Predicted dhole occupancy declined from 0.62 (95\% CI: 0.58-0.66) in 2007 to 0.54 (95\% CI: 0.50-0.58) in 2015. Occupancy was associated with abundance of primary prey species and anthropogenic disturbance. Local extinction appeared to be influenced by forest cover loss, and offset by protected reserves; colonization was influenced by occupancy in neighbouring sites. Perturbation analysis indicated that occupancy was more sensitive to local extinction within reserves and to colonization in sites abutting reserves. The Western Ghats could serve as a stronghold for the endangered dhole, provided future colonizations are facilitated through habitat consolidation beyond reserve boundaries, and local extinctions are prevented by increasing protection efforts within select reserves. We advocate for wildlife managers to adopt a landscape-based approach and periodic monitoring to ensure persistence of the dhole metapopulation in Western Ghats, and in other critical conservation regions across the species{\textquoteright} geographic range.

}, issn = {2045-2322}, doi = {10.1038/s41598-019-39293-0}, author = {Srivathsa, Arjun and Karanth, K Ullas and Kumar, N Samba and Oli, Madan K} } @article {46415, title = {State space and movement specification in open population spatial capture-recapture models.}, journal = {Ecol Evol}, volume = {8}, year = {2018}, month = {2018 Oct}, pages = {10336-10344}, abstract = {

With continued global changes, such as climate change, biodiversity loss, and habitat fragmentation, the need for assessment of long-term population dynamics and population monitoring of threatened species is growing. One powerful way to estimate population size and dynamics is through capture-recapture methods. Spatial capture (SCR) models for open populations make efficient use of capture-recapture data, while being robust to design changes. Relatively few studies have implemented open SCR models, and to date, very few have explored potential issues in defining these models. We develop a series of simulation studies to examine the effects of the state-space definition and between-primary-period movement models on demographic parameter estimation. We demonstrate the implications on a 10-year camera-trap study of tigers in India. The results of our simulation study show that movement biases survival estimates in open SCR models when little is known about between-primary-period movements of animals. The size of the state-space delineation can also bias the estimates of survival in certain cases.We found that both the state-space definition and the between-primary-period movement specification affected survival estimates in the analysis of the tiger dataset (posterior mean estimates of survival ranged from 0.71 to 0.89). In general, we suggest that open SCR models can provide an efficient and flexible framework for long-term monitoring of populations; however, in many cases, realistic modeling of between-primary-period movements is crucial for unbiased estimates of survival and density.

}, issn = {2045-7758}, doi = {10.1002/ece3.4509}, author = {Gardner, Beth and Sollmann, Rahel and Kumar, N Samba and Jathanna, Devcharan and Karanth, K Ullas} } @article {13269, title = {Spatio-temporal interactions facilitate large carnivore sympatry across a resource gradient.}, journal = {Proc Biol Sci}, volume = {284}, year = {2017}, month = {2017 Feb 08}, abstract = {

Species within a guild vary their use of time, space and resources, thereby enabling sympatry. As intra-guild competition intensifies, such behavioural adaptations may become prominent. We assessed mechanisms of facilitating sympatry among dhole (Cuon alpinus), leopard (Panthera pardus) and tiger (Panthera tigris) in tropical forests of India using camera-trap surveys. We examined population-level temporal, spatial and spatio-temporal segregation among them across four reserves representing a gradient of carnivore and prey densities. Temporal and spatial overlaps were higher at lower prey densities. Combined spatio-temporal overlap was minimal, possibly due to chance. We found fine-scale avoidance behaviours at one high-density reserve. Our results suggest that: (i) patterns of spatial, temporal and spatio-temporal segregation in sympatric carnivores do not necessarily mirror each other; (ii) carnivores are likely to adopt temporal, spatial, and spatio-temporal segregation as alternative mechanisms to facilitate sympatry; and (iii) carnivores show adaptability across a gradient of resource availability, a driver of inter-species competition. We discuss behavioural mechanisms that permit carnivores to co-occupy rather than dominate functional niches, and adaptations to varying intensities of competition that are likely to shape structure and dynamics of carnivore guilds.

}, issn = {1471-2954}, doi = {10.1098/rspb.2016.1860}, author = {Karanth, K Ullas and Srivathsa, Arjun and Vasudev, Divya and Puri, Mahi and Parameshwaran, Ravishankar and Kumar, N Samba} }