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Gangadharan A.,Tamil University | Vaidyanathan S.,Foundation for Ecological Research | St. Clair C.C.,University of Alberta
Animal Conservation | Year: 2016

In biodiversity-rich landscapes that are developing rapidly, it is generally impossible to delineate land use and prioritize conservation actions in relation to the full variability of species and their responses to anthropogenic activity. Consequently, conservation policy often focuses on protecting habitat used by a few flagship, indicator or umbrella species like tigers Panthera tigris and Asian elephants Elephas maximus, which potentially leaves out species that do not share these habitat preferences. We demonstrate an empirical approach that clustered 14 mammals into surrogate groups that reflect their unique conservation needs. We surveyed a 787 km2 multiple-use area in the Shencottah Gap of the Western Ghats, India, using foot surveys and camera-trap surveys. Using ecological niche factor analysis, we generated indices of species prevalence (marginality and tolerance) and habitat preferences (factor correlations to marginality axis). We then clustered species by both of the above index types to reveal four clusters based on prevalence and four clusters based on habitat preference. Most clusters contained at least one threatened species. Low-prevalence lion-tailed macaques Macaca silenus and tigers were strongly associated with closed forests and low human disturbance. But elephants, sloth bears Melursus ursinus and gaur Bos gaurus were more tolerant of anthropogenic impact, and sloth bears and gaur preferred open forests and grasslands. Dhole Cuon alpinus and sambar Rusa unicolor were associated with highly anthropogenic habitat (farmland, cash crop and forestry plantations) with high human use. Thus, reliance on flagship species for conservation planning can both underestimate and overestimate the ability of other species to persist in multiple-use landscapes; protecting flagship species would only protect species with similar habitat preferences. For species that avoid human impacts more than the flagship species, core habitat must be protected from human disturbance. For more tolerant species, conservation in anthropogenic habitat may hinge on policies that bolster coexistence with humans. © 2016 The Zoological Society of London.


Joshi A.,Tata Institute of Fundamental Research | Vaidyanathan S.,Foundation for Ecological Research | Mondo S.,Tata Institute of Fundamental Research | Edgaonkar A.,IndiaInstitute of Forest Management | Ramakrishnan U.,Tata Institute of Fundamental Research
PLoS ONE | Year: 2013

Today, most wild tigers live in small, isolated Protected Areas within human dominated landscapes in the Indian subcontinent. Future survival of tigers depends on increasing local population size, as well as maintaining connectivity between populations. While significant conservation effort has been invested in increasing tiger population size, few initiatives have focused on landscape-level connectivity and on understanding the effect different landscape elements have on maintaining connectivity. We combined individual-based genetic and landscape ecology approaches to address this issue in six protected areas with varying tiger densities and separation in the Central Indian tiger landscape. We non-invasively sampled 55 tigers from different protected areas within this landscape. Maximum-likelihood and Bayesian genetic assignment tests indicate long-range tiger dispersal (on the order of 650 km) between protected areas. Further geo-spatial analyses revealed that tiger connectivity was affected by landscape elements such as human settlements, road density and host-population tiger density, but not by distance between populations. Our results elucidate the importance of landscape and habitat viability outside and between protected areas and provide a quantitative approach to test functionality of tiger corridors. We suggest future management strategies aim to minimize urban expansion between protected areas to maximize tiger connectivity. Achieving this goal in the context of ongoing urbanization and need to sustain current economic growth exerts enormous pressure on the remaining tiger habitats and emerges as a big challenge to conserve wild tigers in the Indian subcontinent. © 2013 Joshi et al.


Srinivasaiah N.M.,Tata Institute of Fundamental Research | Anand V.D.,A Rocha India | Vaidyanathan S.,Foundation for Ecological Research | Sinha A.,Indian Institute of Science
PLoS ONE | Year: 2012

Background: A dearth in understanding the behavior of Asian elephants (Elephas maximus) at the scale of populations and individuals has left important management issues, particularly related to human-elephant conflict (HEC), unresolved. Evaluation of differences in behavior and decision-making among individual elephants across groups in response to changing local ecological settings is essential to fill this gap in knowledge and to improve our approaches towards the management and conservation of elephants. Methodology/Principal Findings: We hypothesized certain behavioral decisions that would be made by Asian elephants as reflected in their residence time and movement rates, time-activity budgets, social interactions and group dynamics in response to resource availability and human disturbance in their habitat. This study is based on 200 h of behavioral observations on 60 individually identified elephants and a 184-km2 grid-based survey of their natural and anthropogenic habitats within and outside the Bannerghatta National Park, southern India during the dry season. At a general population level, the behavioral decisions appeared to be guided by the gender, age and group-type of the elephants. At the individual level, the observed variation could be explained only by the idiosyncratic behaviors of individuals and that of their associating conspecific individuals. Recursive partitioning classification trees for residence time of individual elephants indicated that the primary decisions were taken by individuals, independently of their above-mentioned biological and ecological attributes. Conclusions/Significance: Decision-making by Asian elephants thus appears to be determined at two levels, that of the population and, more importantly, the individual. Models based on decision-making by individual elephants have the potential to predict conflict in fragmented landscapes that, in turn, could aid in mitigating HEC. Thus, we must target individuals, in addition to populations, in our efforts to manage and conserve this threatened species, particularly in human-dominated landscapes. © 2012 Srinivasaiah et al.


Nayak R.R.,Wildlife Conservation Society | Nayak R.R.,Center for Wildlife Studies | Vaidyanathan S.,Foundation for Ecological Research | Krishnaswamy J.,Ashoka Trust for Research in Ecology and Environment
Agriculture, Ecosystems and Environment | Year: 2014

Tropical dry forests and savannas are important repositories of plant diversity and ecosystem services in the tropics. These ecosystems are also used extensively for grazing by livestock, and represent a critical element of the rural economy of many tropical countries. Fire is considered as a part of co-evolution in these ecosystems across the globe. However, in recent decades, there has been a shift in historical fire regime. Fire has become more frequent in these landscapes, and could be further enhanced under climate change. This poses threats to existing biodiversity, ecosystem processes, and rural economy. We asked how variability in fire frequency has influenced diversity and heterogeneity in grass species composition, and richness and abundance of grass species preferred by large herbivores (referred to as grazing acceptability) in a South Indian tropical savanna forest. We assumed that an increase in fire frequency acts as the active constraint and limits an ecosystem from attaining the maximum heterogeneity, and the maximum grazing acceptability (maximum richness and abundance of grass species preferred by herbivores) in its native settings. We used MODIS active fire and burned area products to estimate fire frequency across the landscape. A nested sampling approach was used to collect information on vegetation and soil at different fire frequencies. Quantile regression analyses indicated that diversity and heterogeneity in grass species composition as well as grazing acceptability decreased with increasing fire frequencies. We found that livestock grazing intervened with the observed vegetation patterns; grass species diversity and heterogeneity, and grazing acceptability increased with grazing intensity at lower quantiles. Other measured covariates, rainfall, and soil-fertility, alone were not able to explain the observed vegetation patterns in the landscape. The results show a need to control annual fires but allow and manage intermittent fires in this landscape. A complete suppression of fire is not desirable as fire releases nutrients from burning of deeper-rooted vegetation and thus acts as a periodic nutrient pump. It also played an important role in maintaining the grass cover by reducing shrub cover. Hence, it is important to consider the complex interactions between fires-grazers-soil-vegetation to develop effective management practices. We conclude that fire frequency should be managed at low to intermediate levels (one fire in every 5-9 years, resembling the native settings), and grazing regulated, in order to sustain wild and domestic herbivores, biodiversity, and other key ecosystem processes and services over the long-term. © 2014 Elsevier B.V.


Bhalla R.S.,Foundation for Ecological Research | Pelkey N.W.,Juniata College | Prasad K.V.D.,Pondicherry University
Water Resources Management | Year: 2010

We analyse the suitability of Government of India's 2003 and 2008 common guidelines for prioritising micro-watersheds for restoration. These guidelines attempt to balance the need for improved hydraulic function with poverty alleviation and agricultural productivity. To do so, they provide a set of sub-criteria for prioritising micro-watersheds for treatment. We ranked the microwatersheds in the Kalivelli basin in South India based on these sub-criteria. We then compared the 2003 with the 2008 guidelines using GIS and spatial statistics. Visual inspection of the resulting digital maps and spatial autocorrelation analysis showed that individual sub-criteria within a guideline were highly positively auto correlated. Spatial cross-correlations using Mantels test between sub-criteria in the same guidelines produced negative results however. Very different watersheds would have been selected for treatment using the 2003 vs. the 2008 guidelines. While this could have been evidence that the 2008 guidelines were an improvement over the 2003 guidelines, comparing the planning outcomes did not support this conclusion. We conclude that criteria used to select micro-watersheds for hydrologic treatment should be re-formulated emphasizing efffcient resource use and improved hydraulic function prior to social and economic concerns. Finally, we argue that a combined GIS and spatial analysis approach is amenable to quickly evaluating watershed selection criteria as well as assessing post implementation outcomes. © 2010 Springer Science+Business Media B.V.

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