Our research is focused on hornbill biology, interactions between rats, seeds and rainforest trees, tree phenology, understanding patterns and processes in vegetation recovery following shifting cultivation. Past work has focused on monitoring threatened wildlife, understanding anthropogenic effects on wildlife, exploration surveys and management of reserves. Our work with communities has focused on addressing socio-economic needs to enable positive conservation outcomes.
Hornbill biology and conservation
Tropical forest interactions
Conservation education and outreach
- Book ChapterIn pressTop-down or bottom-up: the role of the government and local institutions in regulating shifting cultivation in the Upper Siang district, Eastern Himalaya, India (in press)Shifting Cultivation and Environmental Change: Indigenous People, Agriculture and Forest Conservation (Ed: Malcolm Cairns), Published by Routledge.
- Journal Article2016Field to a forest: Patterns of forest recovery following shifting cultivation in the Eastern HimalayaForest Ecology & Management http://dx.doi.org/10.1016/j.foreco.2016.01.006
The patterns of vegetation recovery in shifting cultivation landscapes that undergo a cycle of clearing, cultivation and forest regeneration are not well understood in Asian tropical forests. We determined for- est recovery patterns by comparing species composition, richness and forest structure in early and late fallows formed following shifting cultivation and in an uncut forest site in a mid-elevation subtropical forest in the Indian Eastern Himalaya. We also examined changes in functional traits of tree species to understand recovery processes with succession. Tree species richness in the 12, 25 and 50-year old sites was 37%, 54% and 82% the value of the richness in uncut forest, respectively, while basal area was 33%, 25% and 41% of the value in uncut forest, respectively. Species composition recovery, however, was low; with even the oldest fallow (50-year fallow) being less than 50% similar to uncut forest in terms of composition. Successional sites that recover over long periods may differ compositionally from uncut forest within a shifting cultivation landscape as these forests are often prone to other anthropogenic dis- turbances. Functional trait analysis revealed that early fallows were colonized by tree species that are animal-dispersed, insect-pollinated with small fruits and seeds, whereas uncut forest and late succes- sional forests were dominated by species that were tall, self-dispersed, wind-pollinated and of high wood density that are dominant mature forest species in the Himalaya. These results are in contrast with the patterns in functional traits of tree species in successional sites from the Neotropics. This points to the importance of site-specificity in succession following shifting cultivation.
- Journal Article2016Shifting to settled cultivation: Changing practices among the Adis in Central Arunachal Pradesh, north-east IndiaAmbio doi 10.1007/s13280-016-0765-x
In the hilly tropics, although shifting cultivation is a widespread practice, government policies have attempted to replace it with other land-uses. However, several factors determine whether farming communities can make the shift. We tried understanding the factors that facilitate or impede the shift to settled cultivation through interviews with the Adi tribe in north-east India. Although settled cultivation was initiated in the sixties, about 90 % of the families practice shifting cultivation, observing 13 festivals associated with the annual agricultural calendar. Our results indicate that the economic status of a household affected the ability to undertake settled cultivation, while labour availability is important for shifting cultivation. Often, these nuances are ignored in government policies. We conclude that future policies should be mindful of cultural and socio-economic factors that affect the community and of the social-ecological resilience of the landscapes and not use a one-size-fits-all strategy.
- Dataset2016Data from: Spatial and temporal variation in hornbill densities in Namdapha Tiger Reserve, Arunachal Pradesh, north-east IndiaDOI: doi:10.5061/dryad.qr068
- Dataset2016Data from: Field to a forest: patterns of forest recovery following shifting cultivation in the eastern Himalaya. Dryad Digital Repository.doi:10.5061/dryad.k83h6
- Report2016NCF Annual Report 2016
- Report2016Hornbill Nest Adoption Program - 2016 breeding seasonHNAP 2016 Report
- Book Chapter2015SciuridsIn: Mammals of South Asia: Volume 2, (eds A. J. T. Johnsingh & N. Manjrekar), pp. 513-573. Universities Press, Hyderabad.
- Journal Article2015Seed dispersal by avian frugivores: non-random heterogeneity at fine scales.Biotropica 47(1): 77-84.Download
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Seed dispersal studies have primarily examined dispersal as a function of distance from the parent tree and/or heterogeneity in dispersal due to animal use of nesting, roosting and sleeping sites. However, non-random heterogeneity in seed dispersal is also likely to result from the post-foraging behavior and movement of frugivores which prefer certain trees. To characterize variation in seed rain at fine scales, we studied the dispersal curve of Prunus ceylanica, a primarily bird-dispersed species. We compared seed rain at conspecifics, heterospecific fruiting trees with similar frugivore assemblages, emergent trees, and the landscape surrounding these trees. Seed rain of P. ceylanica was found to peak globally under the canopy of conspecifics but to peak locally under the canopy and immediate neighborhood of heterospecific fruiting trees. Our results demonstrate that seed rain is highly clumped even at fine spatial scales. A large proportion of seeds are dispersed in specific, localized regions. This variation can have important implications for plant population dynamics and might significantly alter the impact of post-dispersal processes. Seed dispersal models may need to incorporate this heterogeneity to explain manifestations of spatially explicit dynamics like mixed species ‘orchards’.
- Journal Article2015Reduced hornbill abundance associated with low seed arrival and altered recruitment in a hunted and logged tropical forestPLOSOne; DOI: 10.1371/journal.pone.0120062
Logging and hunting are two key direct threats to the survival of wildlife in the tropics, and also disrupt important ecosystem processes. We investigated the impacts of these two factors on the different stages of the seed dispersal cycle, including abundance of plants and their dispersers and dispersal of seeds and recruitment, in a tropical forest in north-east India. We focused on hornbills, which are important seed dispersers in these forests, and their food tree species. We compared abundances of hornbill food tree species in a site with high logging and hunting pressures (heavily disturbed) with a site that had no logging and relatively low levels of hunting (less disturbed) to understand logging impacts on hornbill food tree abundance. We compared hornbill abundances across these two sites. We, then, compared the scatter-dispersed seed arrival of five large-seeded tree species and the recruitment of four of those species. Abundances of hornbill food trees that are preferentially targeted by logging were two times higher in the less disturbed site as compared to the heavily disturbed site while that of hornbills was 22 times higher. The arrival of scatter-dispersed seeds was seven times higher in the less disturbed site. Abundances of recruits of two tree species were significantly higher in the less disturbed site. For another species, abundances of younger recruits were significantly lower while that of older recruits were higher in the heavily disturbed site. Our findings suggest that logging reduces food plant abundance for an important frugivore-seed disperser group, while hunting diminishes disperser abundances, with an associated reduction in seed arrival and altered recruitment of animal-dispersed tree species in the disturbed site. Based on our results, we present a conceptual model depicting the relationships and pathways between vertebrate-dispersed trees, their dispersers, and the impacts of hunting and logging on these pathways.