Scientist, Western Ghats
My primary research interests is in tropical ecology, particularly rainforests and applied ecological subjects such as restoration ecology and conservation biology. I have continuing academic interests in the fields of plant-animal interactions (particularly frugivory and seed dispersal) and animal behaviour.
Hornbills and small carnivores are the animal groups I study and specialize in. I studied the Malabar Grey Hornbill for my Master's dissertation (Salim Ali School of Ecology, Pondicherry University), followed by other studies on hornbills, including nearly a decade of nest monitoring, distribution and abundance surveys along the Western Ghats, and effects of rainforest fragmentation on hornbills. My doctoral thesis (Bharathiar University, Coimbatore) was on the ecology and conservation of the endemic and nocturnal brown palm civet, a frugivorous small carnivore in the tropical rainforests of the Western Ghats.
The broad goal and long-term plan of my research activities is to improve the scientific understanding of the patterns and processes in tropical ecosystems and to use this knowledge for implementation of conservation programmes that would benefit both wildlife and local communities.
- Journal Article2017Successional status, seed dispersal mode and overstorey species influence tree regeneration in tropical rain-forest fragments in Western Ghats, IndiaJournal of Tropical Ecology 33: 270-284. DOI: 10.1017/S0266467417000219
The effects of fragmentation and overstorey tree diversity on tree regeneration were assessed in tropical rain forests of the Western Ghats, India. Ninety plots were sampled for saplings (1–5 cm diameter at breast height (dbh); 5×5-m plots) and overstorey trees (>9.55 cm dbh; 20×20-m plots) within two fragments (32 ha and 18 ha) and two continuous forests. We tested the hypotheses that fragmentation and expected seed-dispersal declines (1) reduce sapling densities and species richness of all species and old-growth species, and increase recruitment of early-successional species, (2) reduce the prevalence of dispersed recruits and (3) increase influence of local overstorey on sapling densities and richness. Continuous forests and fragments had similar sapling densities and species richness overall, but density and richness of old-growth species declined by 62% and 48%, respectively, in fragments. Fragments had 39% lower densities and 24% lower richness of immigrant saplings (presumed dispersed into sites as conspecific adults were absent nearby), and immigrant densities of old-growth bird-dispersed species declined by 79%. Sapling species richness (overall and old-growth) increased with overstorey species richness in fragments, but was unrelated to overstorey richness in continuous forests. Our results show that while forest fragments retain significant sapling diversity, losses of immigrant recruits and increased overstorey influence strengthen barriers to natural regeneration of old-growth tropical rain forests.
- Journal Article2017Bats in the Ghats: Agricultural intensification reduces functional diversity and increases trait filtering in a biodiversity hotspot in IndiaBiological Conservation 210: 48-55.
The responses of bats to land-use change have been extensively studied in temperate zones and the neotropics, but little is known from the palaeotropics. Effective conservation in heavily-populated palaeotropical hotspots requires a better understanding of which bats can and cannot survive in human-modified landscapes. We used catching and acoustic transects to examine bat assemblages in the Western Ghats of India, and identify the species most sensitive to agricultural change. We quantified functional diversity and trait filtering of assemblages in forest fragments, tea and coffee plantations, and along rivers in tea plantations with and without forested corridors, compared to protected forests.
Functional diversity in forest fragments and shade-grown coffee was similar to that in protected forests, but was far lower in tea plantations. Trait filtering was also strongest in tea plantations. Forested river corridors in tea plantations mitigated much of the loss of functional diversity and the trait filtering seen on rivers in tea plantations without forested corridors. The bats most vulnerable to intensive agriculture were frugivorous, large, had short broad wings, or made constant frequency echolocation calls. The last three features are characteristic of forest animal-eating species that typically take large prey, often by gleaning.
Ongoing conservation work to restore forest fragments and retain native trees in coffee plantations should be highly beneficial for bats in this landscape. The maintenance of a mosaic landscape with sufficient patches of forest, shade-grown coffee and riparian corridors will help to maintain landscape wide functional diversity in an area dominated by tea plantations.
- Popular Article2016Rātriñcaranmār [In Malayalam: Night rangers, article on small carnivores].Koodu, October 4(5): 70-72.
- Popular Article2016Hornbills: the feathered foresters.Mudappa, D. 2016. JLR Explore, 15 May 2016.
Most of us are familiar with charismatic mammals such as tigers, elephants and apes. And there are charismatic species amongst birds too: bustards, cranes, eagles. But in the Asian and African tropics are birds that gain charisma from their large size, spectacular appearance, and extraordinary breeding habits: the hornbills.
- Journal Article2016Range extension of the endangered Salim Ali’s Fruit Bat Latidens salimalii (Chiroptera: Pteropodidae) in the Anamalai Hills, Tamil Nadu, India.Journal of Threatened Taxa 8: 9486-9490. http://dx.doi.org/10.11609/jott.2718.104.22.16886-9490
Available here: http://threatenedtaxa.org/index.php/JoTT/article/view/2796/3827
- Popular Article2015Restoring the fabricSanctuary Asia, June 2015, 35(6): 53.
- Popular Article2015When a million turtles landhttps://maptia.com/kalyanvarma/stories/when-a-million-turtles-landDownload
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In a small coastal town in India, every year hundreds of thousands of turtles come en-masse to nest in a small stretch of beach.
- Journal Article2015Invasive alien species in relation to edges and forest structure in tropical rainforest fragments of the Western GhatsTropical Ecology 56: 233-244Download
PDF, 1.03 MB
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 Article2015Landscape scale habitat suitability modelling of bats in the Western Ghats of India:Bats like something in their teaBiological Conservation 191: 529-536.Download
PDF, 1.92 MB
To conserve biodiversity it is imperative that we understand how different species respond to land use change, and determine the scales at which habitat changes affect species' persistence. We used habitat suitability models (HSMs) at spatial scales from 100–4000 m to address these concerns for bats in the Western Ghats of India, a biodiversity hotspot of global importance where the habitat requirements of bats are poorly understood. We used acoustic and capture data to build fine scale HSMs for ten species (Hesperoptenus tickelli, Miniopterus fuliginosus, Miniopterus pusillus, Myotis horsfieldii, Pipistrellus ceylonicus, Megaderma spasma, Hipposideros pomona, Rhinolophus beddomei, Rhinolophus indorouxii and Rhinolophus lepidus) in a tea-dominated landscape. Small (100–500 m) scale habitat variables (e.g. percentage tea plantation cover) and distances to habitat features (e.g. distance to water) were the strongest predictors of bat occurrence, likely due to their high mobility, which enables them to exploit even small or isolated foraging areas. Most species showed a positive response to coffee plantations grown under native shade and to forest fragments, but a negative response to more heavily modified tea plantations. Two species were never recorded in tea plantations. This is the first study of bats in tea planta- tions globally, and the first ecological Old World bat study to combine acoustic and capture data. Our results suggest that although bats respond negatively to tea plantations, tea-dominated landscapes that also contain forest fragments and shade coffee can nevertheless support many bat species.
- Journal Article2015Prey abundance and leopard diet in a plantation and rainforest landscape, Anamalai Hills, Western GhatsCurrent Science 109: 323-330.Download
PDF, 3.54 MB
Leopards use a wide range of habitats from natural forests to plantations in human-dominated landscapes. Within interface areas, understanding leopard ecology and diet can help in conservation management and conflict avoidance. In a fragmented rainforest and plantation landscape in southern India, we examined diet of large carnivores (with a focus on leopards) using scat analysis with DNA-based identification of predator species, and estimated relative abundance of prey species in different land uses through transect surveys. Large carnivores predominantly consumed wild prey species (98.1%) and domestic prey species contributed <2% to overall prey biomass. For leopards, four wild prey species (Indian muntjac, Indian spotted chevrotain, sambar and Indian porcupine) contributed 95.1% of prey biomass, with the rest being minor wild prey species (no livestock in identified scats). Wild prey species occurred across the landscape but varied in relative abundance by land-use type, with forest fragments supporting higher abundance of many species relative to tea and coffee plantations. As large carnivores mainly depend on wild prey and rainforest fragments act as refuges for these mammals within the tea and coffee plantations, it is important to continue to retain or restore these forest fragments.