JPG, 455 KB
Landscape Species, Forests, Grasslands, Plantations, Cow Elephants, 'Matriarch'
- Popular Article2014Faraway, so closeThe Hindu in School, 29 SeptemberDownload
PDF, 1.01 MB
- 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 Article2014Photographic records of the Ratel Mellivora capensis from the southern Indian state of KarnatakaSmall Carnivore Conservation, 50, 42-44.
Understanding about the occurrence and distribution of the Ratel Mellivora capensis from the Indian subcontinent is hindered by the animal’s elusive nature. The first photographic evidence of Ratel for the southern Indian state of Karnataka comprises 41 camera-trap records from Cauvery Wildlife Sanctuary. During January–March 2014, Ratels were detected in the sanctuary’s different forest types broadly in proportion to camera-trapping effort therein. A wider occupancy survey, using a range of methods including camera-trapping, would help obtain a better understanding of the distribution of this cryptic species in Karnataka and neighbouring regions.
- 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.
- Poster2014சிறுத்தையை அறிந்துகொள்வோம்Poster produced in collaboration with Wildlife Conservation Society.Download
PDF, 2.28 MB
சிறுத்தை-மனிதன் எதிர்கொள்ளலைப் பற்றிய விளக்கச் சுவரிதழ்.
- Poster2014Owls and Nocturnal BirdsDownload
PDF, 17.4 MB
Spot-bellied Owl, Brown Hawk Owl, Jungle Owlet, Nightjars, Oriental Bay Owl Brown Fish Owl, Tamil
- Poster2014Rivers and WetlandsDownload
JPG, 1.05 MB
Aquatic Plants, Bamboos, Cormorants, Otters, Stripe-necked Mongooses, Frogs, Whistling Thrush, Damselfly, Tamil
- Journal Article2014Genetic diversity and population structure of Lantana camara in India indicates multiple introductions and gene flow.Plant Biology. 16(3): 651-658.Download
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Lantana camara is a highly invasive plant, which has spread over 60 countries and island groups of Asia, Africa and Australia. In India, it was introduced in the early nineteenth century, since when it has expanded and gradually established itself in almost every available ecosystem. We investigated the genetic diversity and population structure of this plant in India in order to understand its introduction, subsequent range expansion and gene flow. A total of 179 individuals were sequenced at three chloroplast loci and 218 individuals were genotyped for six nuclear microsatellites. Both chloroplasts (nine haplotypes) and microsatellites (83 alleles) showed high genetic diversity. Besides, each type of marker confirmed the presence of private polymorphism. We uncovered low to medium population structure in both markers, and found a faint signal of isolation by distance with microsatellites. Bayesian clustering analyses revealed multiple divergent genetic clusters. Taken together, these findings (i.e. high genetic diversity with private alleles and multiple genetic clusters) suggest that Lantana was introduced multiple times and gradually underwent spatial expansion with recurrent gene flow.
- Journal Article2014Assessing leopard occurrence in the plantation landscape of Valparai, Anamalai HillsCurrent Science 107: 1381-1385.Download
PDF, 6.97 MB
Available from this link: http://www.currentscience.ac.in/Volumes/107/09/1381.pdf
- 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.
- Popular Article2014Mermaid's second lifeDown to Earth, September issue, http://www.downtoearth.org.in/content/mermaids-second-life
- Poster2014Asian ElephantsDownload
PDF, 7.67 MB
Dexterous, Pondorous, Evergreen Forests, Grasslands, Patriarch, Bamboo, Browse, Bark, Ivory, Tamil
- Popular Article2014இலை வெட்டி மர்மம். (On Leafcutter Bee)தி இந்து நாளிதழ். The Hindu Tamil News Daily. 2nd September 2014.
Jeganathan, P. (2014). இலை வெட்டி மர்மம் -தி இந்து நாளிதழ் உயிர்மூச்சு இணைப்பில், ‘இயற்கையின் வாசலில்’ தொடர்எண் – 9. 2nd September 2014. Ilaivetti Marmam– Iyarkayin Vaasalil ArticleSeries No.9 (On Leafcutter Bee). The Hindu Tamil News Daily. 2nd September 2014.
- Popular Article2014அண்டங்காக்கையின் ஆச்சரியத் தேடல். (On Jungle Crows searching and feeding on tadpoles)தி இந்து நாளிதழ். The Hindu Tamil News Daily. 9th September 2014.
Jeganathan, P. (2014). அண்டங்காக்கையின் ஆச்சரியத் தேடல் - தி இந்து நாளிதழ் உயிர்மூச்சு இணைப்பில், ‘இயற்கையின் வாசலில்’ தொடர்எண் – 10. 9th September 2014. Andangkakkaiyin Acharya Thedal– Iyarkayin Vaasalil ArticleSeries No.10 (On Jungle Crows searching and feeding on tadpoles). The Hindu Tamil News Daily. 9th September 2014.
- Journal Article2014Multi-scale factors influencing human attitudes towards snow leopards and wolves.Conservation Biology DOI: 10.1111/cobi.12320
- 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
- Popular Article2014Call of the birdsThe Hindu in School, 31 Dec
- Popular Article2014A Hydra-headed plantThe Hindu in School, 26 November
PDF, 5.91 MB
Black and Orange Flycatcher, Nilgiri Flycatcher, Brown-breasted Flycatcher, Asian Paradise-Flycatcher, Rusty-tailed Flycatcher, Grey-headed Canary Flycatcher, Tamil