- Journal Article2012Impact of vehicular traffic on large mammal use of highway-edges in southern IndiaCurrent Science 102(7): 1047-1051Download
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India’s phenomenal economic growth over the last decade has been accompanied by a much-needed expansion and improvement in transport and other infrastructure networks. While there are legally mandated assessments of the potential ecological impacts of such infrastructure projects prior to implementation, rarely are there post-implementation assessments of their real ecological impacts. In this communication, we present results of a preliminary study examining the impact of vehicular traffic on the usage of road edges by large mammals along a highway passing through Nagarahole Tiger Reserve, southern India. We estimated large mammal encounter rates at remotely triggered camera traps on two consecutive sections of the same highway – one closed to vehicular traffic and the other open to vehicles only during daytime. We observed lower encounter rates of chital, gaur and elephants at camera traps in the highway segment with higher vehicular traffic density, suggesting that these species avoided busy highways. Based on our findings, we emphasize the importance of continued ecological impact assessments of development projects to identify and mitigate unforeseen impacts. Further, an approach to development planning that integrates conservation concerns, especially where development projects coincide with ecologically critical areas, is urgently needed in India.
- Journal Article2012Socio-economic drivers of Forest Cover Change in Assam: A Historical PerspectiveEconomic and Political Weekly 47(5): 64-72Download
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This article analyses the historical context of forest cover change in the upper Brahmaputra Valley of Assam during the precolonial, colonial and the postcolonial periods, locating these changes within the political economy and demographic milieu of each regime.In the current context of rising populations linked to immigration from neighbouring regions, dwindling share of agriculture in the state’s gross domestic product, and recent incentives to small tea growers in risk-prone agricultural landscapes, serious challenges remain to securing forests in this region. Empowering local communities and institutions, understanding tea plantation dynamics and managing the causes and consequences of recent demographic change are crucial to the conservation of forests there.
- Journal Article2012Conservation of the Asian small-clawed otter (Aonyx cinereus) in human-modified landscapes, Western Ghats, IndiaTropical Conservation Science 5: 67-78.Download
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Conservation in human-modified landscapes is important for riparian animals as their habitats extend linearly beyond adjoining protected areas. We examined occupancy and intensity of habitat use of Asian small-clawed otters in coffee and tea plantations and an adjoining protected area in the Western Ghats. We sampled 66 stream segments of 500 m length, using spraints as an indicator of habitat use. Several variables characterising the stream and shoreline were also measured. Occupancy, corrected for detection of spraints, was >0.75 in all three land use types, indicating widespread use of the riparian ecosystem in human-modified landscapes. Intensity of habitat use, however, was much lower in tea (2.08 spraints/500 m) and coffee (2.42) plantations than in the protected area (3.86). Using GLMs we identified the abundance of potential refuges (such as boulders and fallen trees), which was greater in the protected area, as the major factor influencing intensity of habitat use. Shoreline diversity, which was lowest in the tea plantation, might also be another factor. The retention of much of the riparian vegetation and the presence of forest fragments which provide refuges have led to wide occupancy of the tea and coffee plantations although with less intensive use. Sand mining, fishing and infrequent poaching might be other reasons for the relatively low use of human-modified landscape. This study highlights the need to retain remnant forests and riparian vegetation, and to control some human activities for integrated management of species like the small-clawed otter in both protected areas and adjoining human-modified habitats.
- Journal Article2012Optimizing individual identification and survey effort for photographic capture–recapture sampling of species with temporally variable morphological traitsAnimal Conservation 15(2): 174-183
Endangered, wide-ranging megafauna have many threats to contend with during their struggle for survival in an ever-increasing human dominance of the environment. Reliable monitoring of endangered large mammal populations is therefore a critical conservation requirement. Photographic capture–recapture (CR) techniques have opened up avenues for population monitoring of individually recognizable large mammal species. The efficient application of these techniques, however, can be constrained by challenges in reliably identifying individuals arising from the use of multiple, and potentially variable traits, as well as issues of temporal sampling of populations in the field. We address these key problems by describing an automated process of rapidly identifying individual Asian elephants (Elephas maximus) from photographs, and comparing resultant CR-based population parameter estimates with those obtained using supervised visual identification of individuals. In addition, we assess the temporal effort necessary for robust estimation of demographic parameters in our study population. Morphological traits that maintain constancy over time, including variations in tusk characteristics, and ear fold and lobe shape, proved the most reliable for individual identification and subsequent estimation of population parameters. The use of temporally variable traits contributed to high probabilities of misidentification and biased estimates of population size. We found a minimum of seven sampling occasions necessary for reliable population estimation. Our study contributes to design issues for CR studies by providing insights into optimality of sampling effort such that precision of parameter estimates are not compromised while minimizing survey costs. We demonstrate the importance of accurate individual identification in the context of such studies and recommend the use of fixed morphological traits as the optimal individual identification strategy for species where animals are distinguished on the basis of multiple attributes, including some that may be variable over time.
- Journal Article2012Patterns of species participation across multiple mixed-species flock types in a tropical forest in northeastern India.Journal of Natural History. 46(43-44):2749–2762.Download
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We studied mixed-species bird flocks in northeastern India to (a) develop a framework for quantifying species participation in mixed-species flocks, (b) characterize the ecology and behaviour of participant species, and (c) explore mechanisms influencing the coexistence of different mixed-species flock types. To characterize participation in mixed-species flocks, we implement a new method incorporating species abundances, minimizing potential biases in measuring participation arising from differences in the availability of flocking species. There are at least three distinct flock types in the lowland forests of northeastern India; these flock types differ in the body mass and vertical stratum use of participant species. The “core” of mixed-species flocks was composed of a species group that differed much more in their foraging method in comparison with “attendant” species. The exchange of benefits and minimization of interspecific competition might lead to, and maintain, heterogeneity in foraging methods among core species of mixed-species flocks.
- Journal Article2012Averting biodiversity collapse in tropical forest protected areas.Nature 489: 290-294.
- Journal Article2012Standardizing the double-observer survey method for estimating mountain ungulate prey of the endangered snow leopardOecologia DOI: 10.1007/s00442-011-2237-0
- Journal Article2011Agricultural intensification, rainfall patterns, and large waterbird breeding success in the extensively cultivated landscape of Uttar Pradesh, IndiaBiological Conservation 144: 3055-3063. doi:10.1016/j.biocon.2011.09.012
In countries with high human populations, using agricultural areas as multifunctional systems to produce food for humans and retain wildlife may be an efficient conservation strategy for many species. Inclusion of natural habitat and species requirements on agricultural landscapes explicitly into planning processes are precluded by lack of information on drivers of species persistence. Climate change is an additional emerging complexity, and adaptation plans for agricultural landscapes are biased towards intensification to secure long-range food production. I examine the conservation potential of an agricultural landscape in two districts of Uttar Pradesh, north India where agricultural intensification and altered rainfall patterns are predicted to occur. I assess stressors affecting breeding success over eight years of two large waterbirds of conservation concern – Sarus Cranes and Black-necked Storks. Both species had high breeding success that improved with total rainfall and more wetlands in breeding territories. Agricultural and township expansions deteriorated territory quality and reduced breeding success. Sarus Crane populations were predicted to decline relatively rapidly if development activities continued to displace breeding pairs. Black-necked Storks appeared resilient over the long-term notwithstanding reduced breeding success in low-rainfall years. Waterbird nesting habitats (wetlands and trees) were retained in Uttar Pradesh as community lands by villages and by state government via legal provisions suggesting the utility of multiple conservation approaches. Incorporating species requirements explicitly, alongside traditional land use practices conducive for habitat conservation, into adaptation planning and conservation policy will be necessary to retain long-term multifunctionality of such agricultural landscapes.
- Journal Article2011Farmland foods: Black-necked Stork Ephippiorhynchus asiaticus prey items in an agricultural landscapeForktail 27: 98-100
- Journal Article2011Less than wild? Commensal primates and wildlife conservationJournal of Biosciences 36: 749-753
- Journal Article2011Moisture and nutrients determine the distribution and richness of India’s large herbivore species assemblageBasic and Applied Ecology 12(7): 634-642Download
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The goal of this study was to test whether body-mass based foraging principles, guided by plant available moisture (PAM) and plant available nutrients (PAN), could explain large mammalian herbivore species distribution and richness in India. We tested (1) whether the occurrence of larger-bodied herbivore species increases with PAM, but is independent of PAN, (2) whether the occurrence of smaller-bodied herbivore species decreases with PAM, but increases with PAN, and (3) whether herbivore species richness is highest in areas with intermediate PAM and high PAN. We analyzed the distribution and richness of the 16 large (>10 kg) herbivore species found in sub-Himalayan mainland India. Since the distributions of large herbivores in India have been altered by historic human activity, we only used India's largest 76 protected areas as data points, with respect to PAM (log10(rainfall/potential evapotranspiration)), PAN (soil cation exchange capacity), elevation, tree cover, and fire frequency. Using regression and null models to analyze the data, we found positive relations between PAM and the occurrences of the larger-bodied species (elephant and gaur), and negative relations between PAM and the occurrences of smaller-bodied species (chinkara, four-horned antelope and blackbuck). We also found positive relations between the occurrence of the smaller-bodied species and PAN. Large herbivore species richness in India is highest in Kanha and Indravati, areas with high PAN and intermediate PAM. We found that elevation, tree cover and fire frequency were insignificant predictors of herbivore species richness, although elevation and tree cover explained the distribution of a few species. Based on our null model analyses results, we conclude that moisture and soil nutrients are important in determining large herbivore species distribution and richness in sub-Himalayan India.
- Journal Article2011Patterns of spatiotemporal change in large mammal distribution and abundance in the southern Western Ghats, IndiaBiological Conservation 144: 1567-1576Download
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Large mammals face high risks of anthropogenic extinction owing to their larger body mass and associated life history traits. Recent worldwide mammal declines have highlighted the conservation importance of effective assessments of trends in distribution and abundance of species. Yet reliable data depicting the nature and extent of changes in population parameters is sparse, primarily due to logistical problems in covering large areas and difficulties in obtaining reliable information at large spatial scales, particularly over time. We used key informant surveys to generate detection histories for 18 species of large mammals (body mass > 2 kg) at two points in time (present and 30 years ago) in the Southern subregion of the Western Ghats global biodiversity hotspot. Multiple-season occupancy models were used to assess temporal trends in occupancy, detectability and vital rates of extinction and colonization for each species. Our results show significant declines in distribution for large carnivores, the Asian elephant and endemic ungulates and primates. There is a significant decline in detectability for 16 species, which suggests a decline in their abundance. These patterns of change in distribution and abundance repeat in our assessments of spatial variation in occupancy dynamics between the three contiguous forest complexes and two human-dominated landscapes into which the southern Western Ghats has been fragmented. Extinction rates are highest in the human-dominated landscapes. Declines in abundance for several species suggest the presence of extinction debts, which may soon be repaid with imminent range contractions and subsequent species extinctions unless immediate remedial conservation measures are taken. Detection/non-detection surveys of key informants used in an occupancy modeling framework provide potential for rapid conservation status assessments of multiple species across large spatial scales over time.
- Journal Article2010Genetic Polymorphism in the Serotonin Transporter Promoter Region and Ecological Success in MacaquesBehaviour Genetics, 40: 672-679Download
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A well-characterised sequence length poly- morphism in the serotonin transporter promoter region (5-HTTLPR) influences individual behavioural traits and cognitive abilities in humans and rhesus macaques. Maca- ques have been classified into four continuous grades on the basis of their behavioural attributes, ranging from highly hierarchical and nepotistic species to the most egalitarian and tolerant ones. A comparative study of several species that spanned these grades revealed only rhesus macaques to be polymorphic at the 5-HTTLPR and concluded that the polymorphism was responsible for their despotic and aggressive behaviour (Wendland et al., Behav Genet 36:163–172, 2006). We studied wild populations of three other species and found that the egalitarian and tolerant bonnet and Arunachal macaques are also polymorphic while liontailed macaques, although belonging to the same group, are monomorphic. We thus reject a role for this particular polymorphism in interspecific behavioural vari- ability and show that polymorphic species enjoy greater ecological success possibly due to their higher infraspecific variability in individual behavioural traits.
- Journal Article2010Seeing the elephant in the room: human elephant conflict and the Elephant Task Force reportEconomic and Political Weekly 45(49): 29-31Download
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The report of the Elephant Task Force acknowledges the gravityof human-elephant conflicts,and makes a set of potentially far-reaching and forward-looking suggestions to alleviate them. The spirit of most of them is admirable and positive, but the devil, as always, is in the implementation. Managing conflict is as much about protecting farmers and farmlands from elephants as it is about reducing our footprint on the elephant’s domain. The first of five articles that discuss the Elephant Task Force report.
- Journal Article2010Asian elephant Elephas maximus habitat use and ranging in fragmented rainforest and plantations in the Anamalai hills, IndiaTropical Conservation Science 3: 143–158
- Journal Article2010Effects of plantations and home-gardens on tropical forest bird communities and mixed-species bird flocks in the southern Western Ghats.Journal of the Bombay Natural History Society 107: 91-108.Download
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Conservation scientists and policy makers are increasingly aware of the role countryside habitats play in supporting tropical fauna in modern landscapes. We studied the value of different land-uses by examining composition of tropical bird communities and mixed-species bird flocks in human-altered landscapes of Thattekad and the Anamalai Hills, situated in two different altitudes, in the southern Western Ghats. Sixteen line transects distributed across tropical rainforests, shade plantations of coffee and cardamom, timber monocultures of teak, tea plantations, and home-gardens were surveyed for bird flocks, vegetation structure, foliage profile, and canopy attributes. Results indicate that tea plantations were extremely altered habitats, supporting few rainforest species and were devoid of mixed-species bird flocks. Teak monocultures had high species density but were less conducive for rainforest species that require a well developed and structurally more complex habitat. While bird species richness varied little across land-uses, there was significant variation in community composition, with some sensitive bird species absent from all altered habitats. Coffee plantations with surviving rainforest fragments and cardamom plantations with more native shade trees that mimicked a forest habitat supported more rainforest bird species both in communities and flocks. Maintenance of these shade plantations and restoration of forest fragments is recommended, while their conversion into a poor, more open habitat (tea, teak) is strongly discouraged for bird conservation in fragmented landscapes.
- Journal Article2010Ensuring the future of the tiger and other large mammals in the southern portion of the Nilgiri Biosphere Reserve, southern IndiaJournal of the Bombay Natural History Society 107: 77-85Download
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The Nilgiri Biosphere Reserve, at the tri-junction of Tamil Nadu, Kerala and Karnataka, constitutes arguably one of the finest conservation landscapes in the global range of the tiger. We surveyed the southern part of this region, as well as the adjoining areas, to assess the status of large mammals both within and outside protected areas. Our field assessments suggest that large mammals are almost exclusively confined to protected areas with the few remaining populations outside under severe threat from habitat degradation and poaching. However, large stretches of contiguous forests still remain. We suggest the extension of the recently notified Mudumalai Tiger Reserve in Tamil Nadu such that connectivity is retained and strengthened with Biligiri Rangaswamy Temple Wildlife Sanctuary of Karnataka to the north-east and with Silent Valley National Park of Kerala to the south. We also provide suggestions on strengthening conservation in this landscape. The involvement of local communities in the establishment of the Siruvani Conservation Reserve in Kerala and Tamil Nadu, and Nilambur Conservation Reserve in Kerala, will bolster the conservation of large mammals in this landscape. With the suggested extension, Mudumalai Tiger Reserve has the potential of becoming arguably the finest habitat for tigers across Asia, given the variations in altitude, topography and climate which produce a diversity of vegetation types and consequently, provide the tiger with an assortment of prey ranging from Nilgiri Tahr in the high altitude montane grasslands to Blackbuck in the low-lying dry deciduous and thorn scrub forests.
- Journal Article2010Commercializing bycatch can push a fishery beyond economic extinctionConservation Letters 3: 277-285Download
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Tropical bottom trawling is among the most destructive fishing practices, catch- ing large quantities of bycatch, which are usually discarded. We used question- naire surveys of trawl fishers to look at changes in catches over the last 30 years (1978–2008) along India’s Coromandel Coast. We show that catches and in- come from target species have declined sharply over the last two decades. Meanwhile, costs of fishing have increased substantially and now almost ex- ceed income from target species. Over the same period, bycatch (which was traditionally discarded) has now become increasingly marketable, being sold for local consumption, and as fish meal to supply the region’s rapidly growing poultry industry. Without this income from bycatch, the fishery would scarcely be economically viable. While such a change in the use of bycatch is good news in terms of reducing waste and improving livelihoods, it is also responsible for pushing the Indian bottom trawl fishery beyond the economic extinction of its target species.
- Journal Article2010Trawling the shorelinesSeminar. September 2010. Nature without Borders: A symposium on innovative approaches to conserving nature and wildlife
Fishing in India has grown exponentially. It is an industry adapting to its own economic impulses, keeping itself afloat – quite literally – by responding to changes in supply and demand, seeking new markets, repackaging its products and by-products to woo these new markets, reinventing itself constantly in order to survive. The upshot of this industrial inventiveness is that a system of production that should have been designated unsustainable years ago, continues to persist at an increasing ecological cost. And since all of this happens beneath the waves, it largely escapes the noisy debates over the vanishing wilds.
In this paper we present a potted history of trawl fishing along the Indian coastline, and trace its ecological and economic fallout to coastal communities, both human and marine. We discuss the factors currently driving the economics of trawling within the Indian scenario, and explore potential directions towards a more meaningful management of this harvest. Our discussion focuses on fishery off the Coromandel coast, since that is the area we are most familiar with, but it is indicative of much of the rest of the Indian coastline.
- Journal Article2010The birds of Namdapha National Park: recent significant records and a checklist of the species.Forktail 26: 108-132.