- Journal Article2012Distance-related thresholds and influence of the 2004 tsunami on damage and recovery patterns of coral reefs in the Nicobar IslandsCurrent Science 102:1199–1205
The earthquake and tsunami of 2004 resulted in the devastation of marine and coastal ecosystems across the Indian Ocean. However, without adequate baseline information it has been difficult to properly gauge its full impact. The reefs of the Nicobar Islands in the Bay of Bengal lie on a path that ranges from 190 to 500 km from Banda Aceh, the epicentre of the 2004 tsunami. In 2008, we recorded benthic damage as a result of the tsunami to reefs off 14 Nicobar Islands across a gradient of distance from the epicentre. A clear pattern was observed in the demographic structure of the most abundant coral genera, Acropora and Porites across the distance gradient. Significantly, for the largest coral individuals of both genera (> 50 cm diameter), there were distinct threshold effects – their abundance declining dramatically in reefs closer than 350 km from the epicentre. Corals between 20 and 50 cm diameter also increased with distance from the epicentre, but in a more linear fashion. Smaller size classes either showed no apparent trend (Acropora) or decreased linearly (Porites) with distance. These gen- era represent very different life-history strategies: Acropora is fast-growing and highly susceptible to a range of disturbances, while Porites typically grows slowly but is resistant to disturbance. The fact that both genera showed similar thresholds indicates that, close to the epicentre, the impact of the earthquake and tsunami was large enough to override any species- specific resistance. Also, algal cover was also much higher than at locations further north, linked to higher coral mortality at these locations. However, the fact that smaller size class coral individuals were rela- tively abundant and even increased close to the ep centre indicates possible paths of reef recovery after the catastrophe.
- Popular Article2012A problem landscape in the Western GhatsHornbill, April-June, 2012 : 4-8
- Popular Article2012The fading of an invisible mapThe Hindu, February 11th, Magazine Section
- Popular Article2012Expedition North AndamanThe Hindu in School, 12 September
- Popular Article2012No mermaid fairytaleDown to Earth, August issue
- Journal Article2012Conservation needs of the Coconut Crab (Birgus latro) on the Nicobar Islands, IndiaOryx, 46: 175-178.Download
PDF, 139 KB
We describe the distribution of the coconut crab Birgus latro, categorized as Data Deficient on the IUCN Red List, local perspectives towards the species, and its conservation needs on the Nicobar Islands in the eastern Indian Ocean. The species is threatened with extinction across most of its range and in India it is found only on a few islands in the Andaman and Nicobar archipelagoes. We carried out informal discussions with Nicobari commu- nities to examine issues regarding conservation of the species and conducted timed searches in areas where coconut crabs were likely to be found. The discussions revealed that there are social taboos against hunting the coconut crab on most of the Nicobar Islands. However, on some islands these taboos are not being followed and community members may hunt the crab for consumption. Athough the coconut crab is legally protected under the Indian Wildlife Protection Act none of the villagers were aware of this. Of the six islands surveyed we recorded the presence of 17 and 14 crabs on two islands, respectively. On four islands villagers reported the presence of the crab prior to the tsunami of 2004, and on two of these islands the species may now be locally extinct. A small population size and a fragmented distribution in areas of coconut planta- tions suggest that the species is threatened. We recommend monitoring and detailed research on the ecology and genetics of the coconut crab, along with community-based conservation initiatives to conserve the species and its habitat.
- Popular Article2012Of tamarind and toleranceThe Hindu Magazine, 17 June 2012, page 4.
Link to this article here.
- Popular Article2012காணாமல் போகும் சாலையோர உலகம் (On disappearing roadside trees)Puthiya Thalaimurai, Tamil Weekly Magazine, 30 August
காணாமல் போகும் சாலையோர உலகம். காக்கைக் குருவி எங்கள் ஜாதி தொடர்-8. புதிய தலைமுறை. 30ஆகஸ்டு 2012. [Jeganathan, P. (2012).Kanamal Pogum Salaiyora Ulagam. Kakkai Kuruvi Engal Jathi-Series, Article No.8 Puthiya Thalaimurai. 30th August 2012. (On disappearing roadside trees)]
- Journal Article2012To eat and not be eaten: modelling resources and safety in multi-species animal groups.PLoS ONE. 7(7): e42071.Download
PDF, 291 KB
Using mixed-species bird flocks as an example, we model the payoffs for two types of species from participating in multi-species animal groups. Salliers feed on mobile prey, are good sentinels and do not affect prey capture rates of gleaners; gleaners feed on prey on substrates and can enhance the prey capture rate of salliers by flushing prey, but are poor sentinels. These functional types are known from various animal taxa that form multi-species associations. We model costs and benefits of joining groups for a wide range of group compositions under varying abundances of two types of prey–prey on substrates and mobile prey. Our model predicts that gleaners and salliers show a conflict of interest in multi-species groups, because gleaners benefit from increasing numbers of salliers in the group, whereas salliers benefit from increasing gleaner numbers. The model also predicts that the limits to size and variability in composition of multi-species groups are driven by the relative abundance of different types of prey, independent of predation pressure. Our model emphasises resources as a primary driver of temporal and spatial group dynamics, rather than reproductive activity or predation per se, which have hitherto been thought to explain patterns of multi-species group formation and cohesion. The qualitative predictions of the model are supported by empirical patterns from both terrestrial and marine multi-species groups, suggesting that similar mechanisms might underlie group dynamics in a range of taxa. The model also makes novel predictions about group dynamics that can be tested using variation across space and 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.
- Popular Article2012Trans-Himalaya: In the shadows of a giantCare4Nature
- Popular Article2012A thousand leopards in the SeaThe Hindu in School, 29 September
- Popular Article2012Dugongs, mermaids of the seaThe Hindu in School, 26 September
- Journal Article2012Averting biodiversity collapse in tropical forest protected areas.Nature 489: 290-294.
- Popular Article2012The world of bats: echolocationThe Hindu in School, 9 May
- Popular Article2012Dolphins for the GovernorThe Hindu in School, 22 August
- Popular Article2012Bird Migrations: Adaptations and threatsThe Hindu in School, 31 October
- Popular Article2012Not just a boatmanThe Hindu in School, 5 September
- Popular Article2012Jalebis at the forest fenceThe Hindu in School, 6 March
- Journal Article2012Standardizing the double-observer survey method for estimating mountain ungulate prey of the endangered snow leopardOecologia DOI: 10.1007/s00442-011-2237-0