Scientist, Education and Public Engagement
I have two major interests. The first is in Evolutionary Ecology, which is a fancy way of saying that I'm interested in why animals and plants do what they do. That is, how does what they do make sense? For example, why do crows chase away koels from their nests; or why do mosquito larvae move less when they smell danger?
My other main interest is in Citizen Science, or what is often now called Public Participation in Scientific Research. The idea here is that the world is large and complex and is changing rapidly; and to better understand the world we need to work together, all of us, regardless of our background or formal training. Our Citizen Science programmes are run in collaboration with the National Centre for Biological Sciences, as well as other partners. The two main projects we run are MigrantWatch, which looks at the timing of migration of birds; and SeasonWatch, in which we investigate seasonal patterns in leaf-flush, flowering and fruiting of trees. Everyone is welcome to participate!
- Popular Article2016The fall of a squirrelThe Hindu in School, 16 November
- Book2015Birds of peninsular India: a pocket guide to 135 familiar birds
- Book2015What's that bird? Common birds of India
Flashcards of birds for children
- Journal Article2015Demographic superiority with increased logging in tropical understorey birdsJournal of Applied Ecology, 52 (5): 1374-1380
- Journal Article2015Perceptions of priority issues in the conservation of biodiversity and ecosystems in IndiaBiological Conservation, 187: 201-211Download
PDF, 886 KB
We report on the results of a country-wide survey of people’s perceptions of issues relating to the con- servation of biodiversity and ecosystems in India. Our survey, mainly conducted online, yielded 572 respondents, mostly among educated, urban and sub-urban citizens interested in ecological and environ- mental issues. 3160 ‘‘raw’’ questions generated by the survey were iteratively processed by a group of ecologists, environmental and conservation scientists to produce the primary result of this study: a sum- marized list of 152 priority questions for the conservation of India’s biodiversity and ecosystems, which range across 17 broad thematic classes. Of these, three thematic classes—‘‘Policy and Governance’’, ‘‘Biodiversity and Endangered Species’’ and ‘‘Protection and Conservation’’—accounted for the largest number of questions. A comparative analysis of the results of this study with those from similar studies in other regions brought out interesting regional differences in the thematic classes of questions that were emphasized and suggest that local context plays a large role in determining emergent themes. We believe that the ready list of priority issues generated by this study can be a useful guiding framework for conservation practitioners, researchers, citizens, policy makers and funders to focus their resources and efforts in India’s conservation research, action and funding landscape.
- Journal Article2014Genetic diversity and population structure of Lantana camara in India indicates multiple introductions and gene flow.Plant Biology. 16(3): 651-658.Download
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Lantana camara is a highly invasive plant, which has spread over 60 countries and island groups of Asia, Africa and Australia. In India, it was introduced in the early nineteenth century, since when it has expanded and gradually established itself in almost every available ecosystem. We investigated the genetic diversity and population structure of this plant in India in order to understand its introduction, subsequent range expansion and gene flow. A total of 179 individuals were sequenced at three chloroplast loci and 218 individuals were genotyped for six nuclear microsatellites. Both chloroplasts (nine haplotypes) and microsatellites (83 alleles) showed high genetic diversity. Besides, each type of marker confirmed the presence of private polymorphism. We uncovered low to medium population structure in both markers, and found a faint signal of isolation by distance with microsatellites. Bayesian clustering analyses revealed multiple divergent genetic clusters. Taken together, these findings (i.e. high genetic diversity with private alleles and multiple genetic clusters) suggest that Lantana was introduced multiple times and gradually underwent spatial expansion with recurrent gene flow.
- Dataset2013Data from: Influence of gaze and directness of approach on the escape responses of the Indian rock lizard, Psammophilus dorsalis (Gray, 1831).Dryad Digital Repository. doi:10.5061/dryad.1h551
Contains both raw data and analysis scripts. Permanent link to the dataset and scripts on Dryad:
- Journal Article2013Influence of gaze and directness of approach on the escape responses of the Indian Rock Lizard, Psammophilus dorsalis (Gray, 1831).Journal of Biosciences. 38(5): 829–833.Download
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Free download from J. Biosciences webpage:
Animals often evaluate the degree of risk posed by a predator and respond accordingly. Since many predators orient their eyes towards prey while attacking, predator gaze and directness of approach could serve as conspicuous indicators of risk to prey. The ability to perceive these cues and discriminate between high and low predation risk should benefit prey species through both higher survival and decreased energy expenditure. We experimentally examined whether Indian rock lizards (Psammophilus dorsalis) can perceive these two indicators of predation risk by measuring the variation in their fleeing behaviour in response to type of gaze and approach by a human predator. Overall, we found that the gaze and approach of the predator influenced flight initiation distance, which also varied with attributes of the prey (i.e. size/sex and tail-raise behaviour). Flight initiation distance (FID) was 43% longer during direct approaches with direct gaze compared with tangential approaches with averted gaze. In further, exploratory, analyses, we found that FID was 23% shorter for adult male lizards than for female or young male (FYM) lizards. In addition, FYM lizards that showed a tail-raise display during approach had a 71% longer FID than those that did not. Our results suggest that multiple factors influence the decision to flee in animals. Further studies are needed to test the generality of these factors and to investigate the proximate mechanisms underlying flight decisions.
- Journal Article2013Antelope mating strategies facilitate invasion of grasslands by a woody weed.Oikos. 122(10): 1441-1452.Download
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Intra and interspecific variation in frugivore behaviour can have important consequences for seed dispersal outcomes. However, most information comes from among-species comparisons, and within-species variation is relatively poorly understood. We examined how large intraspecific differences in the behaviour of a native disperser, blackbuck antelope Antilope cervicapra, influence dispersal of a woody invasive, Prosopis juliflora, in a grassland ecosystem. Blackbuck disperse P. juliflora seeds through their dung. In lekking blackbuck populations, males defend clustered or dispersed mating territories. Territorial male movement is restricted, and within their territories males defecate on dung-piles. In contrast, mixed-sex herds range over large areas and do not create dung-piles. We expected territorial males to shape seed dispersal patterns, and seed deposition and seedling recruitment to be spatially localized. Territorial males had a disproportionately large influence on seed dispersal. Adult males removed twice as much fruit as females, and seed arrival was disproportionately high on territories. Also, because lek-territories are clustered, seed arrival was spatially highly concentrated. Seedling recruitment was also substantially higher on territories compared with random sites, indicating that the local concentration of seeds created by territorial males continued into high local recruitment of seedlings. Territorial male behaviour may, thus, result in a distinct spatial pattern of invasion of grasslands by the woody P. juliflora. An ex situ experiment showed no beneficial effect of dung and a negative effect of light on seed germination. We conclude that large intraspecific behavioural differences within frugivore populations can result in significant variation in their effectiveness as seed dispersers. Mating strategies in a disperser could shape seed dispersal, seedling recruitment and potentially plant distribution patterns. These mating strategies may aid in the spread of invasives, such as P. juliflora, which could, in turn, negatively influence the behaviour and ecology of native dispersers.
- Journal Article2012To eat and not be eaten: modelling resources and safety in multi-species animal groups.PLoS ONE. 7(7): e42071.Download
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Using mixed-species bird flocks as an example, we model the payoffs for two types of species from participating in multi-species animal groups. Salliers feed on mobile prey, are good sentinels and do not affect prey capture rates of gleaners; gleaners feed on prey on substrates and can enhance the prey capture rate of salliers by flushing prey, but are poor sentinels. These functional types are known from various animal taxa that form multi-species associations. We model costs and benefits of joining groups for a wide range of group compositions under varying abundances of two types of prey–prey on substrates and mobile prey. Our model predicts that gleaners and salliers show a conflict of interest in multi-species groups, because gleaners benefit from increasing numbers of salliers in the group, whereas salliers benefit from increasing gleaner numbers. The model also predicts that the limits to size and variability in composition of multi-species groups are driven by the relative abundance of different types of prey, independent of predation pressure. Our model emphasises resources as a primary driver of temporal and spatial group dynamics, rather than reproductive activity or predation per se, which have hitherto been thought to explain patterns of multi-species group formation and cohesion. The qualitative predictions of the model are supported by empirical patterns from both terrestrial and marine multi-species groups, suggesting that similar mechanisms might underlie group dynamics in a range of taxa. The model also makes novel predictions about group dynamics that can be tested using variation across space and time.