- Journal ArticleIn pressMixed fortunes: old expansion and recent decline in population size of a subtropical montane primate, the Arunachal macaquePLoS One
- Journal ArticleIn pressGoral Nemorhaedus goralIn: A. J. T. Johnsingh and N. Manjrekar (eds.) Mammals of South Asia: ecology, behaviour and conservation. Permanent Black, Delhi.
- Journal ArticleIn pressSerow Nemorhaedus sumatraensisIn: A. J. T. Johnsingh and N. Manjrekar (eds.) Mammals of South Asia: ecology, behaviour and conservation. Permanent Black, Delhi.
- Journal ArticleIn pressHunting or habitat? Drivers of waterbird abundance and community structure in agricultural wetlands of southern IndiaAmbio, DOI: 10.1007/s13280-017-0907-9
The relative impacts of hunting and habitat on waterbird community were studied in agricultural wetlands of southern India. We surveyed wetlands to document waterbird community, and interviewed hunters to document hunting intensity, targeted species, and the motivations for hunting. Our results show that hunting leads to drastic declines in waterbird diversity and numbers, and skew the community towards smaller species. Hunting intensity, water spread, and vegetation cover were the three most important determinants of waterbird abundance and community structure. Species richness, density of piscivorous species, and medium-sized species (31–65 cm) were most affected by hunting. Out of 53 species recorded, 47 were hunted, with a preference for larger birds. Although illegal, hunting has increased in recent years and is driven by market demand. This challenges the widely held belief that waterbird hunting in India is a low intensity, subsistence activity, and undermines the importance of agricultural wetlands in waterbird conservation.
- Journal ArticleIn pressPlaying it safe? Behavioural responses of mosquito larvae encountering a fish predatorEthology, Ecology & Evolution
- Journal Article2017Commensal in conflict: Livestock depredation patterns by free-ranging domestic dogs in the Upper Spiti Landscape, Himachal Pradesh, IndiaAmbio: doi:10.1007/s13280-016-0858-6Download
PDF, 1.89 MB
In human-populated landscapes worldwide, domestic dogs (Canis lupus familiaris) are the most abundant terrestrial carnivore. Although dogs have been used for the protection of livestock from wild carnivores, they have also been implicated as predators of livestock. We used a combination of methods (field surveys, interview surveys, and data from secondary sources) to examine the patterns and factors driving livestock depredation by free-ranging dogs, as well as economic losses to local communities in a Trans-Himalayan agro-pastoralist landscape in India. Our results show that livestock abundance was a better predictor of depredation in the villages than local dog abundance. Dogs mainly killed small-bodied livestock and sheep were the most selected prey. Dogs were responsible for the majority of livestock losses, with losses being comparable to that by snow leopards. This high level of conflict may disrupt community benefits from conservation programs and potentially undermine the conservation efforts in the region through a range of cascading effects.
- Journal Article2017Alternative reproductive tactics and inverse size-assortment in a high-density fish spawning aggregationBMC Ecology, 17:10, DOI 10.1186/s12898-017-0120-5Download
PDF, 1.44 MB
Mating successfully at high densities often requires species to employ unusual reproductive tactics. We report unique courtship behaviours in an un shed, high-density spawning aggregation of squaretail groupers (Plectropomus areolatus) that are potentially associated with alternative reproductive tactics (ARTs). Aggregating males are typically known to court females in small territories (pair courtship), which is often associated with a pair-spawning tactic. However, we also observed the largest males simultaneously courting several females in mid-water shoals – a unique, high-cost-high-benefit courtship tactic which appears to result in a novel school-spawning tactic. Counter-intuitively we observed an inverse size- assortment in individuals–large males courted smaller females and vice-a-versa, likely linked to different pay- offs with competitive ability and local mate density. These unique, high-density behaviours are threatened to be lost, with increasing commercial fishing pressures on the P. areolatus aggregation.
- Journal Article2017From intent to action: A case study for the expansion of tiger conservation from southern IndiaGlobal Ecology and Conservation, 9: 11–20Download
PDF, 2.61 MB
To conserve a large, wide-ranging carnivore like the tiger, it is critical not only to maintain populations at key habitat sites, but also to enable the persistence of the species across much larger landscapes. To do this, it is important to establish well-linked habitat networks where sites for survival and reproduction of tigers are complemented by opportunities for dispersal and colonization. On the ground, expanding protection to areas with a potential for tiger recovery still remains the means of operationalizing the landscape approach. Yet, while the gazetting of protected areas is necessary to enable this, it is not sufficient. It is essential to benchmark and monitor the process by which establishment of protected areas must necessarily be followed by management changes that enable a recovery of tigers, their prey and their habitats. In this paper, we report a case study from the Cauvery and Malai Mahadeshwara Hills Wildlife Sanctuaries of southern India, where we document the infrastructural and institutional changes that ensued after an unprecedented expansion of protected areas in this landscape. Further, we establish ecological benchmarks of the abundance and distribution of tigers, the relative abundance of their prey, and the status of their habitats, against which the recovery of tigers in this area of vast conservation potential may be assessed over time.
- Journal Article2017Coping with catastrophe: foraging plasticity enables a benthic predator to survive in rapidly degrading coral reefsAnimal Behaviour, Vol 131: 13-22. http://dx.doi.org/10.1016/j.anbehav.2017.07.010Download
PDF, 550 KB
Human-induced rapid environmental change (HIREC) disproportionately affects species with specialist traits and long generation times. By circumventing prolonged evolutionary processes, behavioural plasticity is critical in allowing species to cope with rapid environmental changes within their lifetimes. Coral reefs have faced multiple mass mortality events of corals related to climate change in the last two decades. The consequent loss of structural complexity adversely impacts long-lived, structure-dependent fish predators. We attempted to determine how well a guild of groupers (Pisces: Epinephelidae) copes with rapid structural change in the lightly fished Lakshadweep Archipelago, Indian Ocean. Of the 15 species, territorial and site-attached groupers declined exponentially with decreasing structural complexity, while widely ranging species showed no change. However, one site-attached species, the peacock grouper, Cephalopholis argus, maintained high densities across the structural gradient. We explored the mechanisms this species employs to cope with declining habitat structure. Our observations indicate that both a potential release from specialist competitors and plasticity in foraging behaviour (foraging territory size, diet and foraging mode) appeared to favour the peacock grouper's survival in sites of high and low structure. While specialist competitors dropped out of the assemblage, the foraging territory size of peacock groupers increased exponentially with structural decline, but remained constant and compact (50 m2) above a threshold of structural complexity (corresponding to a canopy height of 60 cm). Interestingly, despite significant differences in prey density in sites of high and low structure, gut content and stable isotope analyses indicated that peacock groupers maintained a specialized dietary niche. In-water behavioural observations suggested that diet specialization was maintained by switching foraging modes from a structure-dependent ‘ambush’ to a structure-independent ‘widely foraging’ mode. The remarkable foraging plasticity of species such as the peacock grouper will become increasingly critical in separating winners from losers and may help preserve specialist ecosystem functions as habitats collapse as a result of climate change.
- Journal Article2017Snow Leopard, Ecology and Conservation Issues in IndiaResonance, Indian Academy of Sciences, DOI 10.1007/s12045-017-0511-0Download
PDF, 704 KB
Snow leopard, an elusive mammal species of the cat family, is the top-predator of the Central and South Asian, highaltitude ecosystem. Snow leopards occur at low densities across the Central Asian mountains and the Indian Himalayan region. Owing to their secretive nature and inaccessible habitat, little is known about its ecology and distribution. Due to its endangered status and high aesthetic value, the snow leopard is considered as an ‘umbrella species’ for wildlife conservation in the Indian Himalayas. This article summarizes the current knowledge on snow leopard ecology and conservation issues in the Indian context.
- 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.
- 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.
- Journal Article2017Latitude and live coral cover independently affect butterflyfish & angelfish community distribution in the Andaman & Nicobar archipelago, IndiaMarine Biodiversity. DOI 10.1007/s12526-017-0790-4Download
PDF, 1.41 MB
Latitude and live coral cover independently affect Chaetodontid and Pomacanthid fish community distribution in the Andaman and Nicobar archipelago, India
Empirical evidence indicates that for two reef fish groups, chaetodontids and pomacanthids, live coral cover and latitude determine the local abundance and species richness patterns. Most studies have considered the influence of either live coral cover or latitude in isolation, and the interactive effects that are likely to influence the geographical distribution of species richness and diversity has not been explored. In this study we explored the relationship between (1) species richness and latitude, and (2) species richness and benthic variables, (3) species diversity and latitude and (4) species diversity and benthic variables for butterflyfish (Chaetodontidae) and angelfish (Pomacanthidae) at 75 sites across 51 islands in the Andaman and Nicobar (A & N) archipelago. A total of 30 species of chaetodontids belonging to four genera and 13 species of pomacanthids belonging to nine genera were recorded. We found that live coral cover and latitude were the best predictors for explaining variation in the distribution of these fish communities across the A & N archipelago. This is probably because of the high dependence of these two fish groups on the live coral cover and Nicobar’s geographical proximity to the Coral Triangle, which is considered to be the centre of origin of coral reefs and supports high biodiversity. Our results show that de- spite the high dependence of chaetodontids and pomacanthids on live coral cover, reduction of live coral cover due to a series of disturbance events had limited influence on species richness of these two fish groups, indicating that broad geographical trends are important in explaining variation in species richness for chaetodontid and pomacanthid fish groups.
- Journal Article2017The value of ecosystem services in the high altitude Spiti Valley, Indian Trans-Himalayahttps://doi.org/10.1016/j.ecoser.2017.10.018Download
PDF, 645 KB
The high mountain ranges of South and Central Asia are increasingly being exposed to large-scale development projects. These areas are home to traditional pastoralist communities and internationally important biodiversity including the endangered snow leopard Panthera uncia. Development projects rely on economic cost-benefit analysis, but the ecosystem services in the high Himalayas are poorly understood and are rarely accounted for. As a first step to fill this gap, we identified the main ecosystem services used by local people in the Trans-Himalayan Spiti Valley (7591 km2), a region important for conservation of snow leopards and high mountain biodiversity, and undertook an economic valuation. Stakeholders identified a range of services, though these were dominated by provisioning services identified by 90% of respondents. Only 5.4% of the respondents recognised regulatory services and 4.8% recognised cultural services. The mean economic value of provisioning services was estimated at US$ 3622 ± 149 HH−1 yr−1, which was 3.8 times higher than the average annual household income. Our results underscore the need to account for ecosystem services in the cost-benefit analyses of large-scale development projects in addition to assessments of their environmental and social impact.
- Journal Article2017Evaluating a survey landscape for tiger abundance in the confluence of the Western and Eastern GhatsCurrent Science, Vol 113, No. 9, 1759-1763.Download
PDF, 1.54 MB
Due to the current depleting trends in tiger populations, range countries have committed to double tiger numbers by the year 2022. However, some of the areas, including source sites, across the range countries lack scientifically estimated tiger numbers both at the larger landscape and at the protected area level. Here we report a population of tigers, from Biligirirangaswamy Temple Tiger Reserve, using camera trap based capture-mark recapture in a spatially explicit Likelihood and Bayesian analyses that yielded an estimate of ~55 tigers with a density of about 6.8 tigers/100 km2. Biligirirangaswamy Tiger Reserve nestled in a larger tiger landscape perhaps contributes dispersing individuals to the adjoining forests calling for integrated monitoring and management efforts for the entire landscape. This data set could help in designing long-term, landscape level plans, and outcomes.
- Journal Article2017Assessing changes in distribution of the Endangered snow leopard Panthera uncia and its wild prey over 2 decades in the Indian Himalaya through interviewbased occupancy surveysdoi:10.1017/S0030605317001107Download
PDF, 585 KB
Understanding species distributions, patterns of change and threats can form the basis for assessing the conservation status of elusive species that are difficult to survey. The snow leopard Panthera uncia is the top predator of the Central and South Asian mountains. Knowledge of the distribution and status of this elusive felid and its wild prey is limited. Using recall-based key-informant interviews we estimated site use by snow leopards and their primary wild prey, blue sheep Pseudois nayaur and Asiatic ibex Capra sibirica, across two time periods (past: –; recent: –) in the state of Himachal Pradesh, India. We also conducted a threat assessment for the recent period. Probability of site use was similar across the two time periods for snow leopards, blue sheep and ibex, whereas for wild prey (blue sheep and ibex combined) overall there was an % contraction. Although our surveys were conducted in areas within the presumed distribution range of the snow leopard, we found snow leopards were using only % of the area (, km). Blue sheep and ibex had distinct distribution ranges. Snow leopards and their wild prey were not restricted to protected areas, which encompassed only % of their distribution within the study area. Migratory livestock grazing was pervasive across ibex distribution range and was the most widespread and serious conservation threat. Depredation by free-ranging dogs, and illegal hunting and wildlife trade were the other severe threats. Our results underscore the importance of community-based, landscape- scale conservation approaches and caution against reliance on geophysical and opinion-based distribution maps that have been used to estimate national and global snow leopard ranges.
- Journal Article2017Impact of wild prey availability on livestock predation by snow leopards.Royal Society Open Science, 4(6), 170026.Download
PDF, 566 KB
An increasing proportion of the world's poor is rearing livestock today, and the global livestock population is growing. Livestock predation by large carnivores and their retaliatory killing is becoming an economic and conservation concern. A common recommendation for carnivore conservation and for reducing predation on livestock is to increase wild prey populations based on the assumption that the carnivores will consume this alternative food. Livestock predation, however, could either reduce or intensify with increases in wild prey depending on prey choice and trends in carnivore abundance. We show that the extent of livestock predation by the endangered snow leopard Panthera uncia intensifies with increases in the density of wild ungulate prey, and subsequently stabilizes. We found that snow leopard density, estimated at seven sites, was a positive linear function of the density of wild ungulates—the preferred prey—and showed no discernible relationship with livestock density. We also found that modelled livestock predation increased with livestock density. Our results suggest that snow leopard conservation would benefit from an increase in wild ungulates, but that would intensify the problem of livestock predation for pastoralists. The potential benefits of increased wild prey abundance in reducing livestock predation can be overwhelmed by a resultant increase in snow leopard populations. Snow leopard conservation efforts aimed at facilitating increases in wild prey must be accompanied by greater assistance for better livestock protection and offsetting the economic damage caused by carnivores.
- 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.