Research Programme

The Centre for Ecological Sciences at the Indian Institute of Science offers exciting opportunities for research in a variety of areas in ecology. These include animal behaviour, evolutionary and sociobiology, community and habitat ecology, molecular genetics and conservation biology, large mammal and forest ecology, and climate change. Research is being carried out on a number of taxa, ranging from ants to elephants, and including bees, wasps, crickets, spiders, large mammals, birds and monkeys. The Centre maintains field stations near Mudumalai Wildlife Sanctuary, and in Uttara and Dakshin Kannada in the Western Ghats to facilitate field research in these areas. The projects range from theoretical to laboratory to field-based research with the different approaches being used in a complementary manner.

Animal Behaviour and Community Ecology

Acoustic communication: Research is being carried out on the structure, diversity, perception, function, ecology and evolution of acoustic communication signals, mostly using orthopteran insects as model systems. Nocturnal acoustic communities in tropical evergreen forests are being characterised in respect of acoustic signal structures, spatial and temporal calling patterns and habitat selection in relation to acoustic transmission properties of forest microhabitats. Acoustic sampling is being developed as a rapid, reliable, non-invasive method to monitor cricket species diversity. The phenomenon of acoustic call synchrony between simultaneously calling individuals of a species is being examined in terms of mechanism, as well as ecological and evolutionary factors. The rules by which female crickets sample and select mates, and the role of communication signals in effecting reproductive isolation between species, is also being investigated.

Behavioural and chemical ecology of interactions between species: The mutualistic and antagonistic relationships between species are being investigated using a variety of model systems from the Western Ghats.  In the ant-plant Humboldtia brunonis, the evolution of myrmecophytic traits and the response of ants to the sugar and amino acid compositions of the extrafloral nectar rewards are being studied. The chemical and behavioural basis for the mimicry between ants and ant-mimicking jumping spiders as well as the attraction between wasp pollinators and receptive figs is being investigated. The community ecology of parasitic wasps, their impact on the mutualism between figs and their pollinating wasps and the impact of predatory ants on the mutualism are also being studied. Vision in crepuscular butterflies and nocturnal carpenter bees is being studied to understand their flower and nesting site choices. Models of animal movement strategies are being developed using data from foraging paths taken by giant squirrels (Ratufa indica) through the forest canopy.

Animal Behaviour and Sociobiology

The evolution of cooperation and altruism in animal societies is being studied using social insects such as ants, bees and wasps as experimental model systems. Social insects are used because they exhibit the most spectacular examples of cooperation and altruism and because they are easy to manipulate and study. Questions being addressed include how the members of a social insect colony divide labour among themselves, regulate each other's reproduction, communicate with each other, distinguish their nestmates from non nestmates and how natural selection can lead either to the origin and elaboration or to the loss of sociality. The techniques used include behavioural observations, pheromone extractions and bioassays and the use of microsatellite based molecular markers to estimate genetic relatedness and genetic structure of populations.

The cellular slime mould Dictyostelium is also being used as a model system to study the evolution of altruism. In this soil amoeba, single free-living cells come together when starved and form a multicellular body in which some of the cells die and, in doing so, apparently enhance the reproductive success of the rest. Some of the cells thus behave altruistically. The relative roles of genetic relatedness and epigenetic factors in mediating such altruistic behaviour are being investigated.

Animal Behavior and Trophic Interactions

We investigate behavioural strategies that predators and prey utilise and how they change at different spatial and temporal scales, and with different levels of community complexity. We are also interested in animal decision making, and how they reconcile conflicting information in an uncertain environment. We investigate how local interactions among nearby animals lead to collective synchronous motion in animal groups. We also study adaptive basis of grouping and collective coordinated motion.
Related faculty: Vishwesha Guttal and Maria Thaker

Forest dynamics

The long-term dynamics of forest tree communities in relation to climate, fire, impact of elephants and human disturbance is being examined in permanent plots in the Nilgiri Biosphere Reserve since 1988. Recruitment, growth and survivorship of individuals are being monitored annually. A series of 19 one-hectare plots along a rainfall gradient are also being monitored. The phenology of tree species in montane, deciduous and thorn forestsis is also being studied.
Related Faculty:
R Sukumar

Ecosystems

Our research on ecosystems focuses on three inter-related themes (1) Ecosystem patterns, structures and functions, (2) How ecosystems respond to climatic and anthropogenic influences, (3) Assessing ecological resilience as a conceptual framework to inform ecosystem management. To address these aspects, we use a combination of field experiments, long-term observation and monitoring, mathematical models and statistical tools. A considerable portion of this work is carried in coupled human-natural settings that are not only important for biodiversity conservation, but also provide ecosystem services to support human livelihoods. Students are encouraged to develop inter-disciplinary research questions that overlap with population biology, community ecology, ecosystem science, biogeochemistry, global change, and conservation. Related faculty: Sumanta Bagchi and Vishwesha Guttal

Climate change

Past climate change: The past climate and vegetation of the Nilgiri Hills (about 40,000 years before present), has been studied through stable carbon and oxygen isotope analyses of peat bogs on the plateau. Efforts are also being made to use annual growth rings of trees to understand climate change in the recent past.

Future climate change and its impact: The potential impact of future climate change on forests in India is being assessed through models integrating global and regional climate change projections with vegetation change models. Carbon inventory of forests, adaptation to climate change and mitigation of climate change through changes in land use patterns are other lines of research being pursued. Related Faculty:R. Sukumar and N.H. Ravindranath

Large mammal ecology

The population dynamics of large mammals in Mudumalai Wildlife Sanctuary is studied by long-term monitoring using line transects. The population structures of a number of herbivorous mammals, including elephants, gaur, spotted deer and sambar, are being assessed and the dynamics of their interactions are being modeled. A study of predation patterns of the dhole (Asiatic wild dog) is also in progress. Elephant movement patterns are being examined using radio telemetry and GPS monitoring in West Bengal in order to address human-elephant conflicts in this region and develop early warning systems for field managers on the movement of troublesome elephants. Related Faculty: R Sukumar

Molecular genetics, molecular systematics and phylogeography

Population genetic structure, variation and phylogeography of Asian elephants have been investigated using molecular tools. Similar work is also being carried out on gaurs and Nilgiri tahr. Molecular genetic variation in plants is being studied to understand the effect of pollinator flight distances on gene flow, and the impact of plant visual displays on pollinator visitation.

The problem of delineating species boundaries between closely related congeners is approached by comparing the boundaries obtained using morphological, behavioural and molecular data. This approach is being applied to a number of taxa, including crickets, Hanuman langurs and Hemidactylus geckos. Molecular phylogenetics is also being applied to the study of disjunct avian distributions.
Related Faculty:
Praveen Karanth

 

Diversity: patterns and mechanisms

This research examines the distribution of diversity at various levels of organisation, from genes to ecosystems, and at various scales from local communities to macro-ecological regional scales. At the species level, what determines the structure of communities? How does metapopulation dynamics and island biogeography help in understanding the effects of forest fragmentation on diversity? At the genetic level, how is molecular diversity distributed within and among populations and species? Can understanding these patterns of species diversity and distribution help prioritise areas for conservation? The research currently focuses on herpetofauna in forest systems especially on hotspots of diversity such as the Western Ghats, northeastern India and the Andaman and Nicobar Islands.

Marine turtle biology and conservation

This research continues ongoing work on the ecology and evolutionary biology of marine turtles, including population biology and genetics, and behaviour and movements. It follows from current projects on the phylogeny and population genetics of marine turtles on the coast of India, population monitoring, satellite telemetry and reproductive biology. The focus areas are Orissa, the Andaman and Nicobar Islands, and the Lakshadweep Islands.
Related Faculty:
Kartik Shanker

Behavioural and evolutionary ecology

This research focusses on three themes: first, the ecology and evolution of behaviour and life-histories; second, the consequences of individual behaviour towards population dynamics; and third, the application of insights from behavioural ecology and evolution towards conservation. To address these questions, we use a combination of mathematical modelling, field studies, and meta-analyses. Students can either take up projects under the specific research topics described below or choose topics that fall within the three broad themes described above. Current research areas include (1) Mating system evolution and sexual selection in mammals and birds (2) Evolutionary ecology of invasive species (3) Female life-history strategies and population dynamics.

Ecophysiology

We are particularly interested in understanding the physiological mechanisms that vertebrates use to survive under different natural ecological conditions. For example, how hormonal stress responses vary within and among species along habitat gradients and across geographical areas. We are also investigating how physiological mechanisms underlie behavioural responses and their consequences fortrait complexes across populations and species.
Related Faculty: Maria Thaker

Spatial and Mathematical Ecology

We have established a spatial and mathematical ecology laboratories to investigate, analyze and predict ecological patterns in space and time. Research is underway to predict and analyze patterns of animal movement, and their adaptive significance, in various scenarios such as foraging, migration and predator-prey interactions. We use combination of mathematical and computational models of movement implemented on latest high performance computing systems and evolutionary game theoretic techniques to reveal fundamental principles of animal movement ecology. We are also developing predictive mathematical models to understand spatial organization of vegetation, especially in semi-arid areas. Related faculty: Vishwesha Guttal and Maria Thaker