- Journal Article2015Invasive alien species in relation to edges and forest structure in tropical rainforest fragments of the Western GhatsTropical Ecology 56: 233-244Download
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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.
- Book Chapter2015The Nilgiri TahrPages 409-432 in A. J. T. Johnsingh & N. Manjrekar (editors) Mammals of South Asia. Volume 2. Universities Press, Hyderabad, India.
Keywords: Nilgiritragus hylocrius
- Book Chapter2015Chital Axis axisPages 192-222 in A. J. T. Johnsingh and Nima Manjrekar (Editors), Mammals of South Asia: Volume 2. Universities Press, Hyderabad.
- Book Chapter2015The chevrotainsPages 146-158 in A. J. T. Johnsingh and Nima Manjrekar (Editors), Mammals of South Asia: Volume 2. Universities Press, Hyderabad.
- Popular Article2015The long road to growthThe Hindu, Op-ed Comment, 19 March 2015, Page 9.
As power lines and roads slice up forest cover, it becomes clear that a knowledge economy must tackle development with a wider perspective than that of mere short-term gains. Available from here: http://www.thehindu.com/opinion/op-ed/the-long-road-to-growth/article7008158.ece
In Tamil translation by P. Jeganathan in The Hindu Tamil and here: http://blog.ncf-india.org/2015/04/19/the-long-road-to-growth_tamil-version/
- Popular Article2015Leopard landscapes: coexisting with carnivores in countryside and cityEconomic and Political Weekly, Web Exclusive, 3 January 2015
Web Exclusive, available here:
- Journal Article2015Prey abundance and leopard diet in a plantation and rainforest landscape, Anamalai Hills, Western GhatsCurrent Science 109: 323-330.Download
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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.
- Popular Article2015The other invisible handInternational Health Policies Blog, 4 June 2015.
- Popular Article2015Crop cycles: Fire and renewal in MizoramPeople's Archive of Rural India, 21 April 2015
- Popular Article2015Road to perditionFountain Ink, July 2015, 4(9): 30-44.
The central government has started relaxing norms that protect the environment in favour of industry and development projects, leading to loss of forests, habitat, and wildlife.
Available here: http://fountainink.in/?p=7197&all=1
- Popular Article2015Restoring the fabricSanctuary Asia, June 2015, 35(6): 53.
- Journal Article2015Distribution, relative abundance, and conservation status of Asian elephants in Karnataka, southern IndiaBiological Conservation 187:34-40Download
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Karnataka state in southern India supports a globally significant—and the country’s largest—population of the Asian elephant Elephas maximus. A reliable map of Asian elephant distribution and measures of spatial variation in their abundance, both vital needs for conservation and management action, are unavailable not only in Karnataka, but across its global range. Here, we use various data gathered between 2000 and 2015 to map the distribution of elephants in Karnataka at the scale of the smallest forest management unit, the ‘beat’, while also presenting data on elephant dung density for a subset of ‘elephant beats.’ Elephants occurred in 972 out of 2855 forest beats of Karnataka. Sixty percent of these 972 beats—and 55% of the forest habitat—lay outside notified protected areas (PAs), and included lands designated for agricultural production and human dwelling. While median elephant dung density inside protected areas was nearly thrice as much as outside, elephants routinely occurred in or used habitats outside PAs where human density, land fraction under cultivation, and the interface between human-dominated areas and forests were greater. Based on our data, it is clear that India’s framework for elephant conservation— which legally protects the species wherever it occurs, but protects only some of its habitats—while being appropriate in furthering their conservation within PAs, seriously falters in situations where elephants reside in and/or seasonally use areas outside PAs. Attempts to further elephant conservation in production and dwelling areas have extracted high costs in human, elephant, material and monetary terms in Karnataka. In such settings, conservation planning exercises are necessary to determine where the needs of elephants—or humans—must take priority over the other, and to achieve that in a manner that is based not only on reliable scientific data but also on a process of public reasoning.
- Dataset2015Data from: Does mixed-species flocking influence how birds respond to a gradient of land-use intensity? Proceedings of the Royal Society BDryad Data Repository doi: 10.5061/dryad.vk070
Available here: http://dx.doi.org/10.5061/dryad.vk070
- Journal Article2015Does mixed-species flocking influence how birds respond to a gradient of land-use intensity?Proceedings of the Royal Society B 282: 20151118.Download
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Conservation biology is increasingly concerned with preserving interactions among species such as mutualisms in landscapes facing anthropogenic change. We investigated how one kind of mutualism, mixed-species bird flocks, influences the way in which birds respond to different habitat types of varying land-use intensity. We use data from a well-replicated, large-scale study in Sri Lanka and the Western Ghats of India, in which flocks were observed inside forest reserves, in ‘buffer zones' of degraded forest or timber plantations, and in areas of intensive agriculture. We find flocks affected the responses of birds in three ways: (i) species with high propensity to flock were more sensitive to land use; (ii) different flock types, dominated by different flock leaders, varied in their sensitivity to land use and because following species have distinct preferences for leaders, this can have a cascading effect on followers' habitat selection; and (iii) those forest-interior species that remain outside of forests were found more inside flocks than would be expected by chance, as they may use flocks more in suboptimal habitat. We conclude that designing policies to protect flocks and their leading species may be an effective way to conserve multiple bird species in mixed forest and agricultural landscapes.
PDF also available here: http://dx.doi.org/10.1098/rspb.2015.1118
- 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.
- Popular Article2015Abhi to the rescue!The Hindu in School, 12 AugustDownload
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- Popular Article2015Back home to the healing forestThe Hindu in School, 19 August
- Journal Article2015Fish community reassembly after a coral mass mortality: higher trophic groups are subject to increased rates of extinctionEcology Letters 18(5): 451–461Download
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Since Gleason and Clements, our understanding of community dynamics has been influenced by theories emphasising either dispersal or niche assembly as central to community structuring. Determining the relative importance of these processes in structuring real-world communities remains a challenge. We tracked reef fish community reassembly after a catastrophic coral mortality in a relatively unfished archipelago. We revisited the stochastic model underlying MacArthur and Wilson’s Island Biogeography Theory, with a simple extension to account for trophic identity. Colonisation and extinction rates calculated from decadal presence-absence data based on (1) species neutrality, (2) trophic identity and (3) site-specificity were used to model post-disturbance reassembly, and compared with empirical observations. Results indicate that species neutrality holds within trophic guilds, and trophic identity significantly increases overall model performance. Strikingly, extinction rates increased clearly with trophic position, indicating that fish communities may be inherently susceptible to trophic downgrading even without targeted fishing of top predators.
- Journal Article2015Wetland loss and waterbird use of wetlands in Palwal district, Haryana, India: The role of agriculture, urbanization and conversion to fish pondsWetlands. DOI 10.1007/s13157-014-0600-8Download
PDF, 1.15 MB
Wetlands in tropical and sub-tropical landscapes
are experiencing changes and loss due to urbanization and
intensive human use, but there is sparse detailed understanding
of how these affect use by wetland-dependent birds.
Urbanization and conversion of community wetlands to private
fish ponds are occurring rapidly in Haryana state in north
India. We conducted a study in Palwal district, Haryana in
2013–2014 to simultaneously understand (i) rates and reasons
for wetland loss between 1970s and 2000s, and (ii) relative
importance of location (towns/ villages versus those amid
agriculture) versus site-specific variables on the winter abundance of 31 waterbird species in these fish ponds. Wetland
extent reduced by 52 %, and average wetland size reduced by
42 % between 1970s and 2000s. Expansion of urban areas
converted 105 agricultural wetlands to town wetlands.
Wetlands of different locations could not be differentiated
using waterbird abundance suggesting that wetland conditions
have been homogenized, in part due to conversions to fish
ponds and in part due to urban expansions. Focal waterbird
abundance was affected more due to human activities relative
to location or vegetation. A complex combination of current
management practices and historical determinants of wetland persistence appear to be driving waterbird use of wetlands in
locations like Palwal.
- Popular Article2015Current ecological concerns in the power sector: options to avoid or minimise impactsPages 89-100 in M N Goswami and P Chaudhry (editors) An Epochal Shift in the Idea of India-Meeting aspirations? IPPAI Knowledge Report, Independent Power Producers Association of India, New Delhi.