- 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 pressAnts on Clerodendrum infortunatum: Disentangling Effects of Larceny and HerbivoryEnvironmental Entomology
Nectar larcenists extract nectar from flowers without pollinating them. A reasonable expectation is that any form of nectar larceny should have a detrimental effect on the plant’s reproductive success. However, studies reveal an entire range of effects, from highly negative to highly positive. This variation in effect may be partly explained by additional, unmeasured, effects of nectar larcenists on plants. In a study system where two ant species Tapinoma melanocephalum (Fabr.) (Hymenoptera: Formicidae) and Trichomyrmex destructor (Jerd.) (Hymenoptera: Formicidae) act as nectar larcenists, we examined the effect of larceny on the female reproductive success of Clerodendrum infortunatum Gaertn. (Lamiales: Lamiaceae) in rain forest fragments of the Western Ghats, India. This was done through a combination of field observations and a series of field experiments looking at the effects of excluding ants from inflorescences. We found that T. destructor reduces fruit set considerably. Rather than this being a consequence of nectar larceny, however, our experiments show that the negative effect arises instead from the herbivorous behavior of the ant. At a population level, both ant species prefer edges over interiors of forest patches, spatially concentrating the interaction zone to forest edges. Simultaneously considering multiple ecological interactions and disentangling their relative contributions might explain the large variation across species in the observed effect of larceny. The overall population effect of nectar larceny and herbivory is likely to depend on the spatial structuring of plants and ants.
- Journal ArticleIn pressLocal community neutralizes traditional wolf traps and builds a stupaOryx
- Journal Article2018The role of artificial habitats and rainfall patterns in the unseasonal nesting of Sarus Cranes (Antigone antigone) in south AsiaWaterbirds 41(1): 80-86.
Sarus Cranes (Antigone antigone) in south Asia breed during the rainy season (monsoon), with few nests initiated outside of the monsoon. Several hypothesis have been put forth to explain the unseasonal nesting outside the monsoon, but a careful evaluation of the hypotheses has been absent. Using a multi-year (2004-2017), multi-scale (four Indian states) data set, this study explored the factors potentially responsible for unseasonal nesting by Sarus Cranes. Nests outside the monsoon were very rare (0.3% of all nests) and were initiated when Sarus Crane pairs were in areas with artificial water sources (irrigation canals or reservoirs) or faced abnormal monsoonal conditions. Unseasonal nests were initiated only when breeding pairs had been unsuccessful in raising chicks in the previous primary nesting season. Altered cropping patterns associated with increased artificial irrigation and changing rainfall patterns appear responsible for unseasonal nesting in Sarus Cranes. Nesting of this species outside the monsoon may increase in response to the increasing changes in cropping patterns and changing rainfall conditions.
- Journal Article2018Temporal variations in patterns of Escherichia coli strain diversity and antimicrobial resistance in the migrant Egyptian VultureInfection Ecology and Epidemeology 8:1, 1450590.
Aims: Multiple antimicrobial resistance in Escherichia coli of wild vertebrates is a global concern with scarce assessments on the subject from developing countries that have high human-wild species interactions. We studied the ecology of E. coli in a wintering population of Egyptian Vultures in India to understand temporal changes in both E. coli strains and patterns of antimicrobial resistance.
Methods and Results: We ribotyped E. coli strains and assessed antimicrobial resistance from wintering vultures at a highly synanthropic carcass dump in north-west India. Both E. coli prevalence (90.32%) and resistance to multiple antimicrobials (71.43%) were very high. Clear temporal patterns were apparent. Diversity of strains changed and homogenized at the end of the Vultures’ wintering period, while the resistance pattern showed significantly difference inter-annually, as well as between arrival and departing individuals within a wintering cycle.
Significance of study: The carcass dump environment altered both E. coli strains and multiple antimicrobial resistance in migratory Egyptian Vultures within a season. Long-distance migratory species could therefore disseminate resistant E. coli strains across broad geographical scales rendering regional mitigation strategies to control multiple antimicrobial resistance in bacteria ineffective.
- Journal Article2018Hornbill Watch: A citizen science initiative for Indian hornbillsIndian Birds, 14:65-70Download
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Hornbills are conspicuous and well-known birds with nine species occurring in India. While several hornbill species have been studied extensively in some parts of India, there is a knowledge gap about their distribution, population size, and adaptations to rapidly changing habitats. Most research and conservation efforts are often focused on single or few species within protected areas. Hornbill Watch (henceforth, HW) is an online platform created specifically to record public sightings of hornbills from anywhere in India. The idea is to encourage birders, nature enthusiasts, and photographers to share information on hornbill presence, behaviour, and conservation-related issues. The main objective is to generate baseline information using sight records and enable long-term monitoring of these species by encouraging citizen participation. HW was launched in June 2014, and up to February 2017 had received 938 records from 430 contributors across India, from 26 States and three Union Territories. States from where most sightings were reported were Karnataka, Maharashtra, Tamil Nadu, Assam, and Arunachal Pradesh. Species were reported from both inside (41%), and outside Protected Areas (59%; henceforth, PA). Hornbills were reported from 70 PAs. Fifty-one records of nesting were reported for all species from inside and outside PAs, while 27 records of communal roosting were reported for some species. The data obtained thus far has yielded some useful information and insights,and has the potential for enhancing our understanding of current hornbill distribution patterns, and for identifying important sites for conservation/protection.
- Journal Article2018Breeding biology of Great Hornbill Buceros bicornis in tropical rainforest and human-modified plantation landscape in Western Ghats, IndiaOrnithological Science, 17:205-216Download
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Loss of mature tropical forests to agricultural expansion often creates landscapes with forest fragments embedded within a matrix of human-modified habitats and land uses. Such habitat fragmentation may be detrimental to species with specialized habitat and foraging requirements and their ability to persist in such landscapes may depend on their adaptability to habitat modification. Great Hornbills Buceros bicornis, among the largest birds in Asian tropical rainforests, depend on large trees for nesting and a diverse array of patchily distributed fruiting trees. In the human-modified landscape of the Anamalai Hills, India, we compared the breeding biology and nesting behaviour of Great Hornbills in contiguous rainforest (N=3 nests) and in modified habitat consisting of coffee plantations and rainforest fragments (N=5 nests). The nesting cycle of seven of the eight nests monitored varied between 114 and 130 days. Nest provisioning behaviour was similar in contiguous forest and modified habitat in terms of visitation and food delivery rates, but visitation tended to be higher and food delivery rate lower during the nestling phase than during incubation. As expected, tree density and native food plant diversity were lower in modified habitat than in continuous forest. The diversity of food provisioned was lower in modified habitat with a 57.5% dietary overlap with contiguous forest. Hornbills in the modified habitat of coffee plantations used non-native tree species for nesting and foraging, indicating their adaptability to modified landscapes.
- Journal Article2018eBird in Asia: standardised tools for birdwatchersBirdingASIA, 29:105-108
- Journal Article2018Seasonal variation in wildlife roadkills in plantations and tropical rainforest in the Anamalai Hills, Western Ghats, IndiaCurrent Science. 114(3): 619-626.
- Journal Article2018Context-dependent interactive effects of non-lethal predation on larvae impact adult longevity and body compositionPLoS ONE. 13(2): e0192104
Full text available here:
Predation impacts development, behavior and morphology of prey species thereby shaping their abundances, distribution and community structure. Non-lethal threat of predation, specifically, can have a strong influence on prey lifehistory characteristics. While investigations often focus on the impact of predation threat on prey in isolation, tests of its interactive effects with food availability and resource competition on prey survival and fitness can improve understanding of costs, benefits and trade-offs of anti-predator strategies. This study, involving Aedes aegypti mosquitoes as a model organism, investigates both simple and interactive effects of predation threat during the larval stage on survival, size at and time to maturity, stored teneral reserves of glycogen, protein and lipid in adults, and adult longevity. Our results show that development times of mosquito larvae were increased (by 14.84% in males and by 97.63% in females), and size of eclosing adults decreased (by 62.30% in males and by 58.33% in females) when exposed to lowered nutrition and elevated intraspecific competition, but that predation had no detectable effect on these simple traits. Teneral reserves of glycogen, protein and lipid and adult longevity were positively correlated with adult body size. Non-lethal predation threat had significant interactive effects with nutrition and larval competition on teneral reserves in males and adult longevity in males and females. The sexes responded differently to conditions encountered as larvae, with the larval environment affecting development and adult characteristics more acutely for females than for males. The outcome of this study shows how threat of predation on juveniles can have long-lasting effects on adults that are likely to impact mosquito population dynamics and that may impact disease transmission.
- Journal Article2018Common Starling Sturnus vulgaris in Anini, Arunachal PradeshIndian Birds 14(3): 90
- Journal Article2018Whose habitat is it anyway? Role of natural and anthropogenic habitats in conservation of charismatic speciesTropical Conservation Science 11: 1-5.Download
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Developmental activities have been one of the major drivers of conversion of natural forest areas into mosaics of forest fragments, agriculture, and plantations, threatening the existence of wildlife species in such altered landscapes. Most conservation research and actions are protected area centric and seldom addresses the importance of landscape matrices around these protected areas in providing habitats to a wide range of species. In this article, we bring out the crucial role of natural and anthropogenic habitats for the existence of three charismatic species, namely, Asian elephants, leopard, and lion-tailed macaques. The larger public perception of where the animals should be and where the animals actually are is also discussed. We emphasize that, while habitat generalists often adapt behaviorally and ecologically to modified landscapes, habitat specialists, such as the lion-tailed macaques could find survival harder, with increasing anthropogenic pressures and loss of their habitats.
- 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.