- Popular Article2014அற்புதங்களுக்குப் பின் ஒளிந்திருக்கும் ‘செட்டப்'. (On irresponsible and unethical nature photography)தி இந்து நாளிதழ். The Hindu Tamil News Daily. 11th November 2014.
Jeganathan, P. (2014).அற்புதங்களுக்குப் பின் ஒளிந்திருக்கும் ‘செட்டப்' - தி இந்து நாளிதழ் உயிர்மூச்சு இணைப்பில், ‘இயற்கையின் வாசலில்’ தொடர் எண் – 19. 11th November 2014. Arputhangaluku pin olinthirukum setup– Iyarkayin Vaasalil ArticleSeries No.19 (On irresponsible and unethical nature photography). The Hindu Tamil News Daily. 11th November 2014.
- Poster2014Asian ElephantsDownload
PDF, 7.67 MB
Dexterous, Pondorous, Evergreen Forests, Grasslands, Patriarch, Bamboo, Browse, Bark, Ivory, Tamil
- Poster2014Spotting Elephant SignsDownload
JPG, 353 KB
Dung, Herd, Inefficient Digestion, Debark, Tuskers, Deciduous Forests, Grewia, Teak
PDF, 8.59 MB
Nocturnal, Fruit Eating Bats, Insect Eating Bats, Ultrasonic,Tamil
- Popular Article2014Gardeners of the rainforestSaevus, November 2014, pp. 19-23.
- Journal Article2014Accounting for false positives improves estimates of occupancy from key informant interviewsDiversity and Distributions 20: 223-235Download
PDF, 443 KB
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.
JPG, 318 KB
Prey Animals, Gaur, Sambar, Cubs, Tiger, Poaching, Herbivore Prey
- Poster2014Venomous SnakesDownload
PDF, 20.2 MB
Malabar Pit Viper, Striped Coral Snake, Large-scaled Pit Viper, Hump-nosed Pit Viper, Spectacled Cobra, Common Krait, Rats, Heat-sensitive Pit, 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
PDF, 278 KB
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.
JPG, 455 KB
Landscape Species, Forests, Grasslands, Plantations, Cow Elephants, 'Matriarch'
- Poster2014Tracking Tigers and LeopardsDownload
JPG, 570 KB
Tigers, Leopards, Pugmarks, Soil, Moisture, Claw Marks, Scats, Scrapes, Remains of Prey, Scent-marking
PDF, 17.7 MB
Lithe, Nimble, Palm Civets, Brown Palm Civet, Malabar Civet, Tamil
- 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
- Book Chapter2014Nature Without Borders: An IntroductionPages 1-40 in Rangarajan, M., Madhusudan, M. D., & Shahabuddin, G. (eds.) Nature Without Borders. Orient Blackswan.
PDF, 19.9 MB
White-bellied Woodpecker, Black-rumped Flamebach, Rufous Woodpecker, Speckled Piculet, Tamil
- Poster2014Dhole or Wild DogDownload
PDF, 6.92 MB
Coordinated Hunts, Sambar, Leopard, Chital, Tamil
PDF, 32.2 MB
Two-headed Snake, Earthworms, Insect Larvae, Flattened Tail, Tamil
- Popular Article2014கோடியக்கரை: விருந்தாளிப் பறவைகளின் உல்லாச விடுதி. (On Point Calimere Wildlife Sanctuary)தி இந்து நாளிதழ். The Hindu Tamil News Daily. 22th July 2014.
Jeganathan, P. (2014). கோடியக்கரை: விருந்தாளிப் பறவைகளின் உல்லாச விடுதி - தி இந்து நாளிதழ் உயிர்மூச்சு இணைப்பில், ‘இயற்கையின்வாசலில்’தொடர் எண் – 3. 22th July 2014. Kodiyakkarai: Virunthalip paravaigalin ullasa viduthi – Iyarkayin Vaasalil ArticleSeries No.3 (On Point Calimere Wildlife Sanctuary). The Hindu Tamil News Daily. 22th July 2014.
- Poster2014Tortoise and TurtlesDownload
PDF, 7.04 MB
Indian Pond Terrapin, Cochin Forest Cane Turtle, Travancore Tortoise, Tamil
- 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.