- 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 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.
- 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.
- 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
- Report2016Hornbill Nest Adoption Program - 2016 breeding seasonHNAP 2016 Report
- Report2016NCF Annual Report 2016
- Report2015Hornbill Watch Report June 2014 to May 2015May 2015, www.hornbills.inDownload
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An update that summarises the information obtained on Indian hornbills contributed by people on the Hornbill Watch website for one year (June 2014 to May 2015).
- Popular Article2015Crop cycles: Fire and renewal in MizoramPeople's Archive of Rural India, 21 April 2015
- Journal Article2015Tracking seed fates of tropical tree species: evidence for seed caching in a tropical forest in north-east IndiaPLoS ONEDOI: 10.1371/journal.pone.0134658Download
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Rodents affect the post-dispersal fate of seeds by acting either as on-site seed predators or as secondary dispersers when they scatter-hoard seeds. The tropical forests of north-east India harbour a high diversity of little-studied terrestrial murid and hystricid rodents. We examined the role played by these rodents in determining the seed fates of tropical evergreen tree species in a forest site in north-east India. We selected ten tree species (3 mammal-dispersed and 7 bird-dispersed) that varied in seed size and followed the fates of 10,777 tagged seeds. We used camera traps to determine the identity of rodent visitors, visitation rates and their seed-handling behavior. Seeds of all tree species were handled by at least one rodent taxon. Overall rates of seed removal (44.5%) were much higher than direct on-site seed predation (9.9%), but seed-handling behavior differed between the terrestrial rodent groups: two species of murid rodents removed and cached seeds, and two species of porcupines were on-site seed predators. In addition, a true cricket,Brachytrupessp., cached seeds of three species underground. We found 309 caches formed by the rodents and the cricket; most were single-seeded (79%) and seeds were moved up to 19 m. Over 40% of seeds were re-cached from primary cache locations, while about 12% germinated in the primary caches. Seed removal rates varied widely amongst tree species, from 3% inBeilschmiedia assamicato 97% inActinodaphne obovata. Seed predation was observed in nine species.Chisocheton cumingianus(57%) andPrunus ceylanica(25%) had moderate levels of seed predation while the remaining species had less than 10% seed predation. We hypothesized that seed traits that provide information on resource quantity would influence rodent choice of a seed, while traits that determine resource accessibility would influence whether seeds are removed or eaten. Removal rates significantly decreased (p< 0.001) while predation rates increased (p= 0.06) with seed size. Removal rates were significantly lower for soft seeds (p= 0.002), whereas predation rates were significantly higher on soft seeds (p= 0.01). Our results show that murid rodents play a very important role in affecting the seed fates of tropical trees in the Eastern Himalayas. We also found that the different rodent groups differed in their seed handling behavior and responses to changes in seed characteristics.
- Report2015Hornbill Nest Adoption Program - 2015 Breeding SeasonHNAP 2015 Report
- Journal Article2015Fruit resource tracking by hornbill species at multiple scales in a tropical forest in IndiaJournal of Tropical Ecology, 31:477-490Download
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The fruit-tracking hypothesis predicts a positive association between frugivores and fruit abundance over space and time.We documented hornbill diets and examined the relationship between fruit abundance and abundance of three hornbill species (Buceros bicornis, Rhyticeros undulatus and Aceros nipalensis) in the Eastern Himalaya from 2009– 2012. The study was carried out at three scales: at the largest scale of the study area (15km2), at the intermediate scale – eight 3-ha patches within the study area and at the smallest scale of individual fruiting trees.Ninety-one per cent of the 64 foraging sightings of the great hornbill were on figs while more than 50% of the foraging sightings of the wreathed (83) and rufous-necked hornbills (87) were on non-fig fruits. At the largest scale, wreathed hornbill abundance and ripe fruit abundance peaked in the non-breeding season. At the intermediate scale, wreathed hornbill abundance was positively associated with non-fig fruit availability while rufous-necked hornbill abundance was negatively associated with non-fig fruit availability. At the smallest scale, great and rufous-necked hornbill abundances were correlatedwith fig and non-fig fruit crop sizes, respectively. The three hornbill species track fruit availability at different scales based on diet, which has implications for their role in seed dispersal.
- Book Chapter2015Hope for hornbillsIn: Allison Hegan (Ed.), Endangered Tales.
- Journal Article2015Looking beyond parks: the conservation value of unprotected areas for hornbills in Arunachal Pradesh, Eastern HimalayaOryx, 49:303-311Download
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The loss of tropical forests and associated biodiversity is a global concern. Conservation efforts in tropical countries such as India have mostly focused on state-administered protected areas despite the existence of vast tracts of forest outside these areas. We studied hornbills (Bucerotidae), an ecologically important vertebrate group and a flagship for tropical forest conservation, to assess the importance of forests outside protected areas in Arunachal Pradesh, north-east India. We conducted a state-wide survey to record encounters with hornbills in seven protected areas, six state-managed reserved forests and six community-managed unclassed forests. We estimated the density of hornbills in one protected area, four reserved forests and two unclassed forests in eastern Arunachal Pradesh. The state-wide survey showed that the mean rate of encounter of rufous-necked hornbills Aceros nipalensis was four times higher in protected areas than in reserved forests and 22 times higher in protected areas than in unclassed forests. The mean rate of encounter of wreathed hornbills Rhyticeros undulatus was twice as high in protected areas as in reserved forests and eight times higher in protected areas than in unclassed forests. The densities of rufous-necked hornbill were higher inside protected areas, whereas the densities of great hornbill Buceros bicornis and wreathed hornbill were similar inside and outside protected areas. Key informant surveys revealed possible extirpation of some hornbill species at sites in two protected areas and three unclassed forests. These results highlight a paradoxical situation where individual populations of hornbills are being lost even in some legally protected habitat, whereas they continue to persist over most of the landscape. Better protection within protected areas and creative community- based conservation efforts elsewhere are necessary to maintain hornbill populations in this biodiversity-rich region.
- Journal Article2015Protecting a hornbill haven: a community-based conservation initiative in Arunachal Pradesh, north-east IndiaMalayan Nature Journal, 67 (2): 203-218
- Popular Article2015How the tangkung lost its tailThe Hindu in School, 1 OctoberDownload
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- 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.
- 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’.
- Book Chapter2015SciuridsIn: Mammals of South Asia: Volume 2, (eds A. J. T. Johnsingh & N. Manjrekar), pp. 513-573. Universities Press, Hyderabad.
- Thesis2014Seed dispersal by hornbills, conservation status and the consequences of their decline in tropical forests of Arunachal PradeshManipal University, Manipal, Karnataka