- Dataset2017Playing it safe? behavioural responses of mosquito larvae encountering a fish predator. Ethology Ecology & EvolutionData Dryad. http://dx.doi.org/10.5061/dryad.mc132
- Journal Article2017Plant-disperser mutualisms in a semi-arid habitat invaded by Lantana camara L.Plant Ecology 218 (8): 935-946
Dispersal is an important ecological process that affects plant population structure and community composition. Invasive plants with fleshy fruits rapidly form associations with native and invasive dispersers, and may affect existing native plant-disperser associations. We asked whether frugivore visitation rate and fruit removal was associated with plant characteristics in a community of fleshy-fruited plants and whether an invasive plant receives more visitation and greater fruit removal than native plants in a semi-arid habitat of Andhra Pradesh, India. Tree-watches were undertaken at individuals of nine native and one invasive shrub species to assess the identity, number and fruit removal by avian frugivores. Network analyses and generalised linear mixed-effects models were used to understand species and community-level patterns. All plants received most number of visits from abundant, generalist avian frugivores. Number of frugivore visits and time spent by frugivores at individual plants was positively associated with fruit crop size, while fruit removal was positively associated with number of frugivore visits and their mean foraging time at individual plants. The invasive shrub, Lantana camara L. (Lantana), had lower average frugivore visit rate than the community of fleshy-fruited plants and received similar average frugivore visits but greater average per-hour fruit removal than two other concurrently fruiting native species. Based on the results of our study, we infer that there is little evidence of competition between native plants and Lantana for the dispersal services of native frugivores and that more data are required to assess the nature of these interactions over the long term. We speculate that plant associations with generalist frugivores may increase the functional redundancy of this frugivory network, buffering it against loss of participating species.
- Journal Article2017The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) projectEcology and Evolution, Volume 7, Issue 1 Pages: 145–188
The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.
- Dataset2017Data from: Impact of wild prey availability on livestock predation by snow leopardsData Dryad: doi:10.5061/dryad.8p689
- Book Chapter2017Birds in Relation to Farming and Livestock Grazing in the Indian Trans-HimalayasIn Bird Migration across the Himalayas: Wetland Functioning amidst Mountains and Glaciers
- 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 Article2016The Bay Island Lizard: My Work CompanionsSanctuary Asia, January. http://www.sanctuaryasia.com/magazines/features/10184-the-bay-island-lizard-my-work-companions.html
- 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.
- Journal Article2016Response of the red fox to expansion of human habitation in the Trans-Himalayan mountainsEuropean Journal of Wildlife Research, 62: 131-136, DOI 10.1007/s10344-015-0967-8Download
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Habitat modification through rural and urban expansions negatively impacts most wildlife species. However, anthropogenic food sources in habitations can benefit certain species. The red fox Vulpes vulpes can exploit anthropogenic food, but human subsidies sometimes also sustain populations of its potential competitor, the free-ranging dog Canis familiaris. As human habitations expand, populations of free-ranging dog are increasing in many areas, with unknown effects on wild commensal species such as the red fox. We examined occurrence and diet of red fox along a gradient of village size in a rural mountainous landscape of the Indian Trans-Himalaya. Diet analyses suggest substantial use of anthropogenic food (livestock and garbage) by red fox. Contribution of livestock and garbage to diet of red fox declined and increased, respectively, with increasing village size. Red fox occurrence did not show a clear relationship with village size. Red fox occurrence showed weak positive relationships with density of free-ranging dog and garbage availability, respectively, while density of free-ranging dog showed strong positive relationships with village size and garbage availability, respectively. We highlight the potential conservation concern arising from the strong positive association between density of free-ranging dog and village size.
- Dataset2016Data from: Response of the red fox to expansion of human habitation in the Trans-Himalayan mountainshttp://dx.doi.org/10.5061/dryad.5hs50
- Journal Article2016Providing more protected space for tigers Panthera tigris: a landscape conservation approach in the Western Ghats, southern IndiaOryx 50(2): 336–343Download
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Conservation of large carnivores is challenging as they face various threats, including habitat loss and fragmentation. One of the current challenges to tiger Panthera tigris conservation in India is the conversion of habitat to uses that are incompatible with conservation of the species. Bringing more tiger habitat within a protected area system and in the process creating a network of connected protected areas will deliver dual benefits of wildlife conservation and protection of watersheds. Focusing on the southern Indian state of Karnataka, which holds one of the largest contiguous tiger populations, we attempted to address this challenge using a conservation planning technique that considers ecological, social and political factors. This approach yielded several conservation successes, including an expansion of the protected area network by 2,385 sq km, connection of 23 protected areas, and the creation of three complexes of protected areas, increasing the protected area network in Karnataka from 3.8 to 5.2% of the state’s land area. This represents the largest expansion of protected areas in India since the1970s. Such productive partnerships between government officials and conservationists highlight the importance of complementary roles in conservation planning and implementation.
- Book Chapter2016Richness and size distribution of large herbivores in the HimalayaIn: Asian large herbivore ecology, Ahrestani, F., Sankaran, M. (eds.), Springer.Download
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Species diversity across several taxa ranging from plants to vertebrates is reported to decrease with altitude, or to show a mid-elevation peak in mountain systems. Plant biomass availability for herbivores is similarly expected to decline with altitude as temperature becomes limiting. However, the relationship between herbivore species richness and altitude has not been examined in detail. We show that while the overall regional pattern (gamma-richness) for 25 large-herbivore species (56 % grazers, 44 % browsers/mixed feeders) in the Western Himalayas shows a mid-elevation peak, the species richness of grazers increases nearly monotonically with altitude peaking at 4000–5000 m. Median body mass of herbivores decreased with altitude, suggesting greater suitability of higher elevations for smaller bodied herbivores. We propose that seasonal altitudinal migration patterns, biogeographic influences, increases in the abundance of graminoids, and an increase in plant nutrients with altitude might explain the unusual high grazer species richness at higher altitudes in the Himalayan Mountains.
- Popular Article2016The silence of the lambsCaravan, AprilDownload
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A migratory herder in Pin Valley, Himachal Pradesh, goes into a new area with his flock of sheep-goat in search of pasture. Everything was going fine, but then, suddenly, he lost 10-15 of his sheep. How did he and other fellow herders solve the weird challenge of mysterious death of sheep?
- Popular Article2016A four-horned flash of goldThe Hindu in School, 6 January
- Popular Article2016Rendezvous with GabbarThe Hindu in School, 3 February
- Popular Article2016River under attackThe Hindu in School, 10 February
- Popular Article2016New year on the reefThe Hindu in School, 22 March
- Popular Article2016Is oil palm expansion good for Mizoram?The Frontier Despatch, March 18 – 24, 2016, pages 6-7.