- Journal Article2015Invasive alien species in relation to edges and forest structure in tropical rainforest fragments of the Western GhatsTropical Ecology 56: 233-244Download
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The impact of invasive alien species on native ecosystems is a major conservation issue in the tropics. This study in the rainforest fragments of Anamalai hills, in the Western Ghats biodiversity hotspot, assessed the effects of distance from edges and forest structure on the occurrence and abundance of three invasive alien species (Chromolaena odorata, Lantana camara, and Maesopsis eminii). Replicate line transects were laid from the edges into the interiors of four fragments varying in disturbance level and area (32 ha – 200 ha). Densities of alien species in the protected site were lower than in the three disturbed fragments. Maesopsis eminii occurred at highest density (382 trees/ha) in the highly disturbed site where it also showed prolific regeneration (1510 saplings/ha). The invasive alien species showed no clear edge-to-interior pattern, instead their abundance appeared to be localized and related in a site-specific manner to disturbances such as presence of Eucalyptus plantation, canopy openings, and trails.
- Journal Article2015Distribution, relative abundance, and conservation status of Asian elephants in Karnataka, southern IndiaBiological Conservation 187:34-40Download
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Karnataka state in southern India supports a globally significant—and the country’s largest—population of the Asian elephant Elephas maximus. A reliable map of Asian elephant distribution and measures of spatial variation in their abundance, both vital needs for conservation and management action, are unavailable not only in Karnataka, but across its global range. Here, we use various data gathered between 2000 and 2015 to map the distribution of elephants in Karnataka at the scale of the smallest forest management unit, the ‘beat’, while also presenting data on elephant dung density for a subset of ‘elephant beats.’ Elephants occurred in 972 out of 2855 forest beats of Karnataka. Sixty percent of these 972 beats—and 55% of the forest habitat—lay outside notified protected areas (PAs), and included lands designated for agricultural production and human dwelling. While median elephant dung density inside protected areas was nearly thrice as much as outside, elephants routinely occurred in or used habitats outside PAs where human density, land fraction under cultivation, and the interface between human-dominated areas and forests were greater. Based on our data, it is clear that India’s framework for elephant conservation— which legally protects the species wherever it occurs, but protects only some of its habitats—while being appropriate in furthering their conservation within PAs, seriously falters in situations where elephants reside in and/or seasonally use areas outside PAs. Attempts to further elephant conservation in production and dwelling areas have extracted high costs in human, elephant, material and monetary terms in Karnataka. In such settings, conservation planning exercises are necessary to determine where the needs of elephants—or humans—must take priority over the other, and to achieve that in a manner that is based not only on reliable scientific data but also on a process of public reasoning.
- Journal Article2015Changes in the institution of family among the ChangpasLadakh Studies 32 • January 2015 • 4 - 17Download
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This paper focuses on the Changpas of Kargyam, with a specific focus on rules, norms, and patterns that govern the construction of social relationships in the family system and the factors that have influenced it. It provides an overview and description of these changes based on fieldwork carried out in 2010-12. Some of the important factors are the increased presence of Indian security forces after the 1962 Indo-China war, tourism, a new motor road, educational facilities and various government welfare schemes. Each of these factors has had an impact on the social structure of Changpa communities
- Journal Article2015Does mixed-species flocking influence how birds respond to a gradient of land-use intensity?Proceedings of the Royal Society B 282: 20151118.Download
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Conservation biology is increasingly concerned with preserving interactions among species such as mutualisms in landscapes facing anthropogenic change. We investigated how one kind of mutualism, mixed-species bird flocks, influences the way in which birds respond to different habitat types of varying land-use intensity. We use data from a well-replicated, large-scale study in Sri Lanka and the Western Ghats of India, in which flocks were observed inside forest reserves, in ‘buffer zones' of degraded forest or timber plantations, and in areas of intensive agriculture. We find flocks affected the responses of birds in three ways: (i) species with high propensity to flock were more sensitive to land use; (ii) different flock types, dominated by different flock leaders, varied in their sensitivity to land use and because following species have distinct preferences for leaders, this can have a cascading effect on followers' habitat selection; and (iii) those forest-interior species that remain outside of forests were found more inside flocks than would be expected by chance, as they may use flocks more in suboptimal habitat. We conclude that designing policies to protect flocks and their leading species may be an effective way to conserve multiple bird species in mixed forest and agricultural landscapes.
PDF also available here: http://dx.doi.org/10.1098/rspb.2015.1118
- Journal Article2014Long-lived benthic predators require structurally stable reefs in the face of repeated climate-change disturbancesCoral Reefs. 33: 289-302
Benthic recovery from climate-related disturbances does not always warrant a commensurate functional recovery for reef-associated fish communities. Here, we examine the distribution of benthic groupers (family Serranidae) in coral reef communities from the Lakshadweep archipelago (Arabian Sea) in response to structural complexity and long-term habitat stability. These coral reefs that have been subject to two major El Nin ̃o Southern Oscillation-related coral bleaching events in the last decades (1998 and 2010). First, we employ a long-term (12-yr) benthic- monitoring dataset to track habitat structural stability at twelve reef sites in the archipelago. Structural stability of reefs was strongly driven by exposure to monsoon storms and depth, which made deeper and more sheltered reefs on the eastern aspect more stable than the more exposed (western) and shallower reefs. We surveyed groupers (species richness, abundance, biomass) in 60 sites across the entire archipelago, representing both exposures and depths. Sites were selected along a gradient of structural complexity from very low to high. Grouper biomass appeared to vary with habitat stability with significant differences between depth and exposure; sheltered deep reefs had a higher grouper biomass than either sheltered shallow or exposed (deep and shallow) reefs. Species richness and abundance showed similar (though not significant) trends. More interestingly, average grouper biomass increased exponentially with structural complexity, but only at the sheltered deep (high stability) sites, despite the availability of recovered structure at exposed deep and shallow sites (lower-stability sites). This trend was especially pronounced for long-lived groupers (life span [10 yrs). These results suggest that long-lived groupers may prefer temporally stable reefs, independent of the local availability of habitat structure. In reefs subject to repeated disturbances, the presence of structurally stable reefs may be critical as refuges for functionally important, long-lived species like groupers.
- Journal Article2014Seagrasses in the age of sea turtle conservation and shark overfishingFrontiers in Marine Science 1:28. doi: 10.3389/fmars. 2014.00028.Download
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Efforts to conserve globally declining herbivorous green sea turtles have resulted in promising growth of some populations. These trends could significantly impact critical ecosystem services provided by seagrass meadows on which turtles feed. Expanding turtle populations could improve seagrass ecosystem health by removing seagrass biomass and preventing of the formation of sediment anoxia. However, overfishing of large sharks, the primary green turtle predators, could facilitate turtle populations growing beyond historical sizes and trigger detrimental ecosystem impacts mirroring those on land when top predators were extirpated. Experimental data from multiple ocean basins suggest that increasing turtle populations can negatively impact seagrasses, including triggering virtual ecosystem collapse. Impacts of large turtle populations on seagrasses are reduced in the presence of intact shark populations. Healthy populations of sharks and turtles, therefore, are likely vital to restoring or maintaining seagrass ecosystem structure, function, and their value in supporting fisheries and as a carbon sink.
- Journal Article2014A case of colour aberration in Stripe-necked Mongoose Herpestes vitticollis in the Western Ghats, IndiaSmall Carnivore Conservation 50: 76-77.
- Journal Article2014Roads emerging as a critical threat to leopards in India?Cat News 60 Spring 2014 (30)
Leopards (Panthera pardus) face severe threat from poaching, loss of habitat and killing in retaliation to conflict. However, in India a new threat appears to be emerging in the form of vehicle accident mortalities. In the past 60 months 23 leopards have been recorded as killed due to road accidents in the southern Indian state of Karnataka alone. When roads overlap with important wildlife habitats, considerable scrutiny and critical conservation planning is urgently required
- Journal Article2014Bats in Indian coffee plantations: doing more good than harm?Current Science 107: 1958-1960.Download
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Many bat species occur in Indian coffee plantations and despite sporadic reports of damage to commercial coffee crops, the literature shows little evidence for these claims. Measures that have been proposed to ‘control’ fruit bats are likely to be ineffective and even counter-productive. Instead, insect-eating bats should be encouraged by planters as they help control herbivorous and disease-carrying insects, while fruit bats pollinate flowers and disperse seeds of many useful plants and shade tree species. More research is needed to quantify any crop damage caused by bats and to look for sustainable solutions where necessary.
PDF also available here: http://www.currentscience.ac.in/Volumes/107/12/1958.pdf
- Journal Article2014Accounting for false positives improves estimates of occupancy from key informant interviewsDiversity and Distributions 20: 223-235Download
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Much research in conservation biogeography is fundamentally dependent on obtaining reliable data on species distributions across space and time. Such data are now increasingly being generated using various types of public surveys. These data are often integrated with occupancy models to evaluate distributional patterns, range dynamics and conservation status of multiple species at broad spatio-temporal scales. Occupancy models have traditionally corrected for imperfect detection due to false negatives while implicitly assuming that false positives do not occur. However, public survey data are also prone to false-positive errors, which when unaccounted for can cause bias in occupancy estimates. We test whether false positives in a dataset collected from public surveys lead to overestimation of species site occupancy and whether estimators that simultaneously account for false-positive and false-negative errors improve occupancy estimates.
Western Ghats, India.
We fit occupancy models that simultaneously account for false positives and negatives to data collected from a large-scale key informant interview survey for 30 species of large vertebrates. We tested their performance against standard occupancy models that account only for false negatives.
Standard occupancy models that correct only for false negatives tended to overestimate species occupancy due to false-positive errors. Occupancy models that simultaneously accounted for false positives and negatives had greater support [lower Akaike's information criterion (AIC)] and, consistent with predictions, generated systematically lower occupancy estimates than standard models. Furthermore, accounting for false positives improved the accuracy of occupancy estimates despite the added complexity to the statistical estimator.
Integrating large-scale public surveys with occupancy modelling approaches is a powerful tool for informing conservation and management. However, in many if not most cases, it will be important to explicitly account for false positives to ensure the reliability of occupancy estimates obtained from public survey datasets such as key informant interviews, volunteer surveys, citizen science programmes, historical archives and acoustic surveys.
- Journal Article2014Acoustic identification of bats in the southern Western Ghats, IndiaActa Chiropterologica 16: 213–222Download
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Bats play crucial roles in ecosystems, are increasingly used as bio-indicators and are an important component of tropical diversity. Ecological studies and conservation-oriented monitoring of bats in the tropics benefit from published libraries of echolocation calls, which are not readily available for many tropical ecosystems. Here, we present the echolocation calls of 15 species from the Valparai plateau in the Anamalai Hills, southern Western Ghats of India: three rhinolophids (Rhinolophus beddomei, R. rouxii (indorouxii), R. lepidus), one hipposiderid (Hipposideros pomona), nine vespertilionids (Barbastella leucomelas darjelingensis, Hesperoptenus tickelli, Miniopterus fuliginosus, M. pusillus, Myotis horsfieldii, M. montivagus, Pipistrellus ceylonicus, Scotophilus heathii, S. kuhlii), one pteropodid (Rousettus leschenaultii) and one megadermatid (Megaderma spasma). Discriminant function analyses using leave-one-out cross validation classified bats producing calls with a strong constant frequency (CF) component with 100% success and bats producing frequency modulated (FM) calls with 90% success. For five species, we report their echolocation calls for the first time, and we present call frequencies for some species that differ from those published from other parts of the species’ ranges. This exemplifies the need for more local call libraries from tropical regions to be collected and published in order to record endemic species and accurately identify species whose calls vary biogeographically.
PDF also available here: http://dx.doi.org/10.3161/150811014X683408
- Journal Article2014An elephantine challenge: human–elephant conflict distribution in the largest Asian elephant population, southern IndiaBiodiversity Conservation DOI 10.1007/s10531-014-0621-xDownload
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Wildlife conservation is a complex issue especially when it involves large carnivores or mega-herbivores that are conflict-prone. Karnataka state in southern India is known to harbor high density of wild elephants. This conservation success story also has opportunity costs for communities living in close proximity to elephants. Despite the fact that human–elephant conflict is a serious conservation and social issue, there is little quantitative understanding of conflict especially over large areas. Here we conduct the first analysis of human–elephant conflict distribution, severity and explanatory factors over the entire state of Karnataka. We use data from the state forest department records on villages that experience conflict, compensation payments made by the government, elephant den- sities, forest cover and perimeter, and presence of physical barriers to mitigate elephant conflict. In total, 60,939 incidences of crop loss were reported and US$ 2.99 m paid in compensation during April 2008–March 2011. A total of 91 people were killed by ele- phants and 101 elephants died in retaliatory killings during the study period. A total of 9.4 % of the state’s geographic area covering 25 of the 42 forest administrative divisions were affected. There was no significant difference in conflict incidences or compensation given between protected areas and non-protected areas. There was no correlation between conflict incidences/unit area and elephant density, forest cover, forest perimeter of pro- tected areas and presence of physical barriers. The results depict the importance of efficient management of physical barriers, conserving key habitat linkages, and acts as baseline data for future work.
- Journal Article2014Spatio-temporal variation in forest cover and biomass across sacred groves in a human-modified landscape of India's Western GhatsBiological Conservation 178: 193-199.
Although the potential for community-conserved areas (CCAs) to extend conservation beyond formal protected areas is widely acknowledged, the scarcity of conservation assessments and monitoring hinders the rigorous evaluation of their effectiveness in many regions. In India, which hosts a high density and diversity of CCAs, the need for more assessments of the ecological and socio- economic properties of these systems to guide conservation planning and policy has been emphasized in recent years. We inventoried the extant sacred grove network against official records of 407 groves across 70 villages in the Kodagu District of India's Western Ghats, and interviewed local communities about their management and conservation. We also evaluated recent trends in aboveground biomass of sacred groves using time-series satellite data from six time-points during the 2000-2010 period, and made comparisons to corresponding trends in nearby State-managed protected forests. Although most of the larger (> 2ha) groves officially listed were forested at present, over two-thirds of the smaller groves listed were either not forested or could not be located. Local communities attributed these declines to encroachment and illicit logging. Time-series satellite data revealed aboveground biomass declines of ~0.5% annually across the sacred grove network over the 2000-2010 period. In contrast, biomass increased during this period at the interiors and edges of State-managed forests in the landscape. Our results highlight that the conservation status of even well-protected CCAs can vary considerably over time, especially given the dynamism in socio-economic, cultural and ecological factors that govern their status. We argue that understanding and addressing this dynamism is crucial to the conservation of CCAs.
- Journal Article2014Vigorous Dynamics Underlie a Stable Population of the Endangered Snow Leopard Panthera uncia in Tost Mountains, South Gobi, MongoliaPLoS One. DOI: 10.1371/journal.pone.0101319
- Journal Article2014Tiger poaching and trafficking in India: estimating rates of occurrence and detection over four decadesBiological Conservation, doi: 10.1016/j.biocon.2014.08.016
Poaching, prey depletion and habitat destruction have decimated the world’s wild tiger population to fewer than 3200–4000. Despite focused efforts, poaching continues to be the key threat to tiger populations in India, home to more than half of the world’s tigers. A rise in the number of incidences of tiger poaching and trafficking may not essentially represent an increase in the actual occurrence of tiger poaching and trafficking, but can instead be an indication of better enforcement. With ad hoc detection rates, it becomes difficult to estimate the true quantum of poaching and the efficiency of enforcement. We empirically estimate the probability of occurrence of tiger crime and that of detecting it during periods of 3–7 years in the past 40 years in the 605 districts of India. We test the hypotheses that tiger crime is influenced by the presence of tiger trade hubs, proximity to a number of tiger habitats, and that tiger poachers prefer to use rail routes over road highways. The annual probability of detecting tiger crime was estimated to be highest (0.46, 95% CI = 0.38–0.54) in the period between 1993 and 1995. Our results identify 73 districts as current tiger crime hotspots with high (>0.5) probability of occurrence of tiger crime. We propose that the probability of occurrence of tiger crime can be a more reliable estimator of changing poaching pressures and that probability of detecting tiger crime provides a robust estimate of the efficiency in tackling tiger poaching and trafficking.
- Journal Article2014The cashmere connection, biodiversity, and climate: response to Von Wehrden, et al
- Journal Article2014Multi-scale factors influencing human attitudes towards snow leopards and wolves.Conservation Biology DOI: 10.1111/cobi.12320
- Journal Article2014The response of birds and mixed-species bird flocks to human-modified landscapes in Sri Lanka and southern IndiaForest Ecology and Management 329: 384–392Download
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While there is no substitute for undisturbed forest, secondary forests and agroforests are increasingly common in tropical areas and may be critical to conservation plans. We compared the diversity and abundance of birds and the characteristics of mixed-species bird flocks in forests inside protected reserves to ‘‘buffer’’ areas, consisting of degraded forests and non-native timber plantations at reserve boundaries, and to agricultural areas. We monitored a network of 57 transects placed over an altitudinal gradient (90–2180 masl) in Sri Lanka and southern India, collecting 398 complete flock observations and 35,686 observations of birds inside and outside of flocks over two years. Flocks were rarely found in agri- cultural areas. However, the density of flocks in buffer areas was similar to that in forests, although buffer flocks were smaller in average flock size and differed significantly in composition, as measured by the proportion of species that were classified, from the literature, as forest interior or open-landscape species. While flock composition was distinct between agricultural, buffer and forest areas, the differences in the composition of flocks was not as great as the differences between the overall communities in these different habitats. Considering buffer transects alone, pine plantations retained fewer forest interior species in flocks than did forests, and small areas of agriculture and abandoned agriculture attracted open-landscape species. Though clearly not equivalent to protected forests, degraded forests and agroforests in buffer areas still hold some conservation value, with forest species found particularly in mixed-species flocks in these human-modified habitats.
- Journal Article2014Local and Landscape Correlates of Primate Distribution and Extinction in Upper Brahmaputra ValleyConservation Biology 28(1): 95-106Download
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Habitat fragmentation affects species distribution and abundance, and drives extinctions. Es- calated tropical deforestation and fragmentation have confined many species populations to habitat rem- nants. How worthwhile is it to invest scarce resources in conserving habitat remnants within densely settled production landscapes? Are these fragments fated to lose species anyway? If not, do other ecologi- cal, anthropogenic, and species-related factors mitigate the effect of fragmentation and offer conservation opportunities? We evaluated, using generalized linear models in an information-theoretic framework, the effect of local- and landscape-scale factors on the richness, abundance, distribution, and local extinction of 6 primate species in 42 lowland tropical rainforest fragments of the Upper Brahmaputra Valley, northeastern India. On average, the forest fragments lost at least one species in the last 30 years but retained half their original species complement. Species richness declined as proportion of habitat lost increased but was not significantly affected by fragment size and isolation. The occurrence of western hoolock gibbon (Hoolock hoolock) and capped langur (Trachypithecus pileatus) in fragments was inversely related to their isolation and loss of habitat, respectively. Fragment area determined stump-tailed (Macaca arctoides) and northern pig-tailed macaque occurrence (Macaca leonina). Assamese macaque (Macaca assamensis) distribution was affected negatively by illegal tree felling, and rhesus macaque (Macaca mulatta) abundance increased as habitat heterogeneity increased. Primate extinction in a fragment was primarily governed by the extent of divergence in its food tree species richness from that in contiguous forests. We suggest the conservation value of these fragments is high because collectively they retained the entire original species pool and individually retained half of it, even a century after fragmentation. Given the extensive habitat and species loss, however, these fragments urgently require protection and active ecological restoration to sustain this rich primate assemblage.
- Journal Article2014Tracing the geographic origin of traded leopardbody parts in the Indian subcontinent withDNA-based assignment testsConservation Biology, 2014, DOI: 10.1111/cobi.12393Download
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Illicit trade in wildlife products is rapidly decimating many species across the globe. Such trade is often underestimated for wide-ranging species until it is too late for the survival of their remaining populations. Policing this trade could be vastly improved if one could reliably determine geographic origins of illegal wildlife products and identify areas where greater enforcement is needed. Using DNA-based assignment tests (i.e., samples are assigned to geographic locations), we addressed these factors for leopards (Panthera pardus) on the Indian subcontinent. We created geography-specific allele frequencies from a genetic reference database of 173 leopards across India to infer geographic origins of DNA samples from 40 seized leopard skins. Sensitivity analyses of samples of known geographic origins and assignments of seized skins demonstrated robust assignments for Indian leopards. We found that confiscated pelts seized in small numbers were not necessarily from local leopards. The geographic footprint of large seizures appeared to be bigger than the cumulative footprint of several smaller seizures, indicating widespread leopard poaching across the subcontinent. Our seized samples had male-biased sex ratios, especially the large seizures. From multiple seized sample assignments, we identified central India as a poaching hotspot for leopards. The techniques we applied can be used to identify origins of seized illegal wildlife products and trade routes at the subcontinent scale and beyond.