CES In-house Symposium 2014: Abstracts

Aniruddha Dutta Roy

Title- A peek into the evolutionary origin of skinks of the Indian subcontinent. (30 min)

Abstract

Skinks are the largest and most diverse family of lizards living today. They are remarkably diverse not just in terms of the number of species, but also diversity of traits. Because of this reason, skinks are increasingly being used as a model system in order to study the evolution of traits such as limb loss. Even within the Indian subcontinent, skinks are one of the most speciose families of lizards occupying almost all kinds of habitats. Lygosominae and Scincinae are the largest subfamilies within skinks and the Indian subcontinent has representatives of both. Knowing the unique biogeographic history of the Indian subcontinent, it would be interesting to understand when and how the skinks in the subcontinent have come from. My talk revolves around a few phylogenetic studies on Indian skinks wherein I try to trace their evolutionary origin.

Anjan Kumar Nandi

Title – Dominance networks in social wasps: detecting substructure and beyond. (15 min)

Abstract

During the past two decades, network science has evolved as a very powerful tool in the analysis of different complex systems. Dominance interaction networks constructed from the behavioral observations in the social wasp Ropalidia marginata are found out to be structurally similar to different biological and technological regulatory networks. The presence of specific substructure elements suggests that the network is capable of information transfer more efficiently than a randomized network. These findings are consistent with the hypothesis that, in the course of evolution, the dominance behavior in primitively eusocial wasps has been adapted for information transfer in addition to its primal function of reproductive monopolization.

Bharath H. Aithal

Title – Visualisation of urbanisation patterns in Greater Bangalore, India. (15 min)

Abstract

Rapid urbanization is one of the crucial issues of global change during the 21st century affecting the human dimensions. Unplanned urbanization has led to the over exploitation of natural resources with significant impacts on ecosystem structure and its functional abilities threatening urban sustainable development. Urbanisation interacts with the neighboring landscape structures in the form of commuter’s flow, pollution, obtaining food grain, which create dispersed growth or sprawl in between the metropolis and the semi urban area, and these areas are often devoid of basic amenities. Landscape transformation under the influence of urbanization is multi-directional and differentiated in time and space. The best approach to understand the process of urbanization and its consequences is by quantifying spatial patterns. Prediction of future growth is essential to control the uncontrolled development and plan for sustainable cities. Predictive models are useful as they foresee spatial changes based on the historical land uses, which helps the decision makers in planning the growth including sprawl across the city periphery.

Focus of this talk is to discuss the land use changes in Bangalore and modeling based on agents and the past trends in land use changes. Visualisation of urbanisation by 2020 is done using Land Change Modeler (LCM), Geomod and Fuzzy AHP based modelling. The potential of Markov chain and cellular automata model for predicting the spatial and temporal urban growth dynamics is also explored for rapidly urbanizing Bangalore, India. The results suggest further peri urban expansion and degradation of environment by 2020 despite limited water resource in the region.

 

Dr. Deepak Veerappan

Title – Preliminary findings on the phylogeography and systematics of the fan-throated lizards Sitana cf. ponticeriana. (30 min)

Abstract

Sitana cf. ponticeriana is a small terrestrial lizard found in the dry zones of the Indian sub region. Past studies on the genus in Terai region of Nepal led to discovery of three distinct species in a small geographic area. In the current study sampling was carried out in 70 different locations in seven different states of India. Preliminary phylogenetic analysis using just mitochondrial DNA data suggests that fan-throated lizards belong to a cryptic species complex with six distinct clades and many undescribed species. Mapping of their dewlap colour and hemipenial morphology on the phylogeny suggest that they have evolved certain traits multiple times during the course of diversification. Morphometric analyses of select morphotypes from some of the clades have shown remarkable variation in body ratios. Variations in scale counts was insufficient to separate all the morphotypes but were informative in separating a few.

Divya B.

Title- Capturing richness independent phylogenetic diversity and testing PD surrogates in woody plant communities. (30 min)

Abstract

Phylogenetic diversity (PD) is a measure of biodiversity that incorporates the evolutionary relationship between the organisms. This study elucidates the significance of using PD over taxon richness as a measure of biodiversity. We show that, by using intensive quadratic entropy (J), one can measure diversity in a richness independent manner. We also demonstrate that node-based-PD and richness-at-higher-taxonomic-levels are not good surrogates for PD as has previously been proposed.

Ganesh Hegde

Title – Solar energy for rural Electrification: Rooftop PV for domestic and standalone systems for irrigation. (15 min)

Abstract

Energy is essential for economic and social development of a region. Dependence on fossil fuels has posed a serious threat due to greenhouse gas (GHG) emissions, dwindling stock of the fuel resource base. Among daily activities, about 80% of the mechanical work requires electrical energy. Dependence on the conventional energy resources for electricity generation is eroding the resources at faster rate. The process of electricity generation causes significant adverse effect on ecology by producing enormous quantity of byproducts including nuclear waste and carbon dioxide. Improving energy efficiency, switch over to renewable sources of energy and de-linking economic development from energy consumption (particularly of fossil fuels) is essential for sustainable development of a region. Green energy technologies have gained importance so that they are reliable and environmental friendly. Electrical energy harvesting from solar radiations is one such promising technology which uses photoelectric effect. Rooftop SPV installation and utilization of barren land for solar energy harvesting is a promising method to exploit more energy from sun to meet regional domestic and irrigation demand.

Jaideep Joshi

Title – Collective movement and evolution of altruism. (15 min)

Abstract

Altruism is extremely difficult to evolve in nature, unless altruists interact more often than chance with other altruists. This can happen by several mechanisms, including kin recognition, and spatial structuring. We show that in even in the absence of kin recognition, collective movement governed by simple local interactions like attraction and alignment to neighbours, could co-evolve with altruistic behaviour, creating favourable spatial structures that can sustain altruism.

Dr. Kavita Isvaran

Title – Is the distribution of reproductive success among females relatively uniform in birds and mammals? (15 min)

Abstract

The way in which reproductive success is distributed among individuals of a sex within a population has attracted much attention because this variation represents the potential for selection to act within a population. Studies exploring differences between species in the variance in reproductive success have largely focussed on males because intrasexual competition for mates, a process that can generate much variance in reproductive success, is typically expected to be much more intense in males than in females, particularly in mammals and birds. So, is reproductive success then uniformly distributed among females in populations of birds and mammals? Surprisingly, the generality of this expected pattern has not been formally examined. Here, I discuss patterns in the distribution of female reproductive success in mammals and birds and processes that may generate high reproductive skew among females.

Kunal Arekar

Title – Determining the species status of the Himalayan populations of Hanuman langur. (15 min)

Abstract

The Hanuman langur (Semnopithecus entellus, Sub-family Colobinae) is widely distributed throughout India and also found in Sri Lanka, parts of Bangladesh, Pakistan and Nepal. Two major forms of this langur have been recognised based on their tail morphology: the Northern type (NT), which has a tail that loops forward, and the southern type (ST), which has a tail that loops backward.

The Himalayan langur is NT Hanuman langur, but it is morphologically different from the Hanuman langur found in the plains of North India. Hill has classified the Himalayan ones into a different species, Semnopithecus schistaceus. Again there have been many classification schemes which have assigned these langurs to various species and subspecies. In this study we will try to determine if the Himalayan population is genetically and ecologically distinct from the population in the plains, and if so, then elevate this to species level.

Monisha Bhattacharya

Title – Reproductive isolation through song in two sympatric tree cricket species. (15 min)

Abstract

Oecanthus henryi and Oecanthus indicus are sympatric tree cricket species found in South India. The calls of both the species consists of chirps made up of syllables. However the number of syllables per chirp and other temporal parameters differ between the two calls making the calls unique. With change in temperature the carrier frequency of the call changes for both the species and shows some overlap at lower temperatures. The present talk will focus on reproductive isolation in these two species through the mechanism of temporal pattern recognition, explored through behavioural experiments in Oecanthus henryi.

Nitin Saxena

Title – Understanding the pattern of evolution of schooling behavior in fish using phylogenetic approach. (15 min)

Abstract

Collective behaviour has been observed in nature in various organisms ranging from prokaryotes to multicellular, high order eukaryotic organisms. We here try to focus on collective behavior in fish which record for high variability. With the help of advances in the field of phylogenetics, we have tried to trace the pattern of schooling behavior in fish along different lineages. We worked on Carangidae family belonging to order Perciformes.

Navendu Page

Title – Patterns in local, regional and turnover diversity in the evergreen woody plants of the Western Ghats. (15 min)

Abstract

The evergreen tree communities of Western Ghats exhibit substantial variation in species richness along its latitudinal extent. This provide an ideal scenario for studying how regional species diversity (gamma) is expressed as diversity within (alpha) and across habitats (beta). Studying the interrelationships between alpha, beta and gamma may provide useful insights into the role of local processes in determining the size of the regional species pool. In this study we explore the patterns in alpha and beta diversity across the latitudinal gradient of the Western Ghats and its consequence on gamma diversity.

Paromita Saha

Title- To be updated. (15 min)

Dr. Praveen Karanth

Title – Phylogenetic diversity as a measure of biodiversity: Pros and cons. (30 min)

Abstract

One of the commonly used measures of biodiversity is species richness which is the numbers of different species presented in an area. Typically areas with higher species richness are accorded greater conservation value. However species richness often underestimates true diversity as it does not take into account how different the species are from each other. For example an area with four species of lizards and another area with four species of reptiles (a lizard, a snake, a crocodile and a tortoise) will both be assigned the same value for reptile richness. Nevertheless the second area has greater diversity as it harbours very different composition of reptiles. To correct for this discrepancy, diversity can be measured at higher levels (genus or family or order), but here again a true picture does not emerge due to taxonomic uncertainty and discordance between taxonomic rank and age of the taxonomic group. In this regard, molecular phylogenies are very useful. In this talk I will introduce the concept of phylogenetic diversity (PD) to illustrate some of these issues. Furthermore I will contrast species richness with PD and discuss the powers of such comparisons for rating areas for conservation action.

Dr. Raghavendra Gadagkar

Title- Worker Policing in Social Hymenoptera: are ugly data destroying a beautiful theory, and what we should do about it? (30 min)

Abstract

Hamilton’s rule, though now under attack, has been a powerful conceptual framework to understand the evolution of social behaviour. It follows from Hamilton’s rule that workers in polyandrous hymenopteran societies should destroy each other’s male-destined eggs and only rear the queen’s sons. There is considerable empirical support for this claim and indeed worker policing is considered one of the most powerful tests of Hamilton’s rule. There are however many conceptual problems and some contradicting data. I will present the theory, both sides of the empirical story and argue that it is in the interest, even of the supporters of the theory, to pay more attention to its potential weakness.

Ravi Jhambekar

Title – Impact of the Invasive Weed Lantana camara (Verbenaceae) on Butterfly behaviour. (15 min)

Abstract

Invasive species, now a major cause of extinction worldwide, are thought to reduce native biodiversity and influence native plant-animal interactions through a wide range of direct and indirect effects. We examine the influence of one such invasive plant in tropical forests of India, Lantana camara, on butterfly communities. Here, we address the hypothesis that lantana by dominating an area reduces the diversity of resources and microhabitats essential for butterflies leading to reduced habitat use by butterflies. We test the predictions that butterflies should show a reduced suite of behaviours in lantana-dominated areas compared with native vegetation; and the reduced diversity in resources should result in fewer butterfly species regularly using lantana-dominated patches. To test these predictions, multiple plots were laid in areas dominated with lantana and those consisting of only native vegetation in two forest types. Behavioural observations were made in each of these plots through one-hour sampling sessions spread through the day. Butterfly abundance and the number of species using these plots were estimated using point sampling. We found that butterflies showed significant behavioural differences between areas dominated by lantana and native vegetation. Furthermore, fewer butterfly species and individuals were recorded in lantana-dominated plots compared with native vegetation plots particularly in one forest type. These findings suggest that one mechanism by which an invasive plant may affect native butterfly communities is by changing the distribution of resources needed by the organisms leading to reduced habitat use and ultimately to reduced population sizes and local extinctions.

Dr. Renee M. Borges

Title – Do plant and animals differ in phenotypic plasticity? (30 min)

Abstract

This talk will attempt to answer or present relevant findings on some key issues related to phenotypic plasticity in plants versus that of animals.

1) Is the reaction norm in plants greater than that in animals?

2) How does the supra-cellular nature of plants contribute to their plasticity?

3) Are there stem cell differences between plants and animals and do these contribute to plasticity differences?

4) How do the autotrophy of plants and the concept of local sources versus sinks contribute to developmental plasticity? Are these concepts applicable to animals, in whole (e.g. sedentary, photosynthesizing composites such as Cnidaria) or in part (e.g. circulatory systems, nutrient acquisition and transport systems)?

5) What is the role of ancient signaling mechanisms such as those involving reactive oxygen species (ROS) and nitric oxide (NO) in phenotypic plasticity?

Dr. Rohini Balakrishnan

Title – Temperature, size and song frequency in tree crickets. (30 min)

Abstract

In most cricket species, males use narrow bandwidth, species-specific calling songs produced by rubbing the forewings to attract females from a distance. Females recognize males of their species based on temporal and spectral attributes of their calling songs. Females are typically sharply tuned to the carrier frequency of conspecific male calling song, both physiologically and behaviourally. Tree crickets of the genus Oecanthus are however known to change the carrier frequency of their songs with temperature, prompting the term ‘thermometer crickets.’ We investigated the mechanisms responsible for the change in carrier frequency using laser Doppler vibrometry and finite element modelling. We found that wing geometry, specifically aspect ratio as well as the nature of the driving mechanism accounted for the change in carrier frequency with temperature. Since the carrier frequency of tree crickets changes with temperature, this should pose a problem for female receivers: they should adopt the strategy either of changing the frequency to which they are tuned with temperature or have a broad enough tuning to encompass the range of variation of male song with temperature. We carried out a series of biophysical and behavioural experiments on the tree cricket Oecanthus henryi to test these alternatives. We found that females adopt the latter strategy and the mechanical frequency response of the eardrum (tympanum) is in fact exceptionally flat, with no indication of tuning at higher song intensities.

Rutuja Chitra Tarak

Title – Trees shrink: how much did they grow then? (15 min)

Abstract

Tree growth in forest inventories is typically estimated by measuring tree trunk diameter increment with a tape, or a fixed band. However, tree diameter changes not only due to wood increment, but also due to water flux in and out of the stem. Tree stem thus expands & shrinks, at daily to multi-year scale. Unmeasured as this factor remains, we are left with unknown inaccuracy in tree growth estimates. As seasonally dry tropical forests (SDTFs) experience high variability in water availability, this inaccuracy could be substantial. Thus I set out to estimate these errors in measuring tree growth in SDTFs of Southern India.

Sabiha Sachdeva

Title – Anticipating the regime shifts in ecosystems using spatial data. (15 min)

Abstract

Naturally changing drivers and/or human induced activities can cause abrupt shifts in ecosystems from one state to an alternative state. Such shifts, as in eutrophication of lakes of desertification, can lead to loss of productivity of ecosystems. It is difficult to predict these shifts because the system hardly changes before the abrupt transition. Recently, studies based on ideas from non-equilibrium phase transitions,have proposed early warning signals of abrupt ecological transitions. However, owing to complexity of ecological systems a precise parameterization of value of drivers or state of the system at which transitions occurs remains a daunting task. Using a simple spatially explicit model of vegetation, we have developed a method to estimate the value of the ecological state variable and the driver at which a tipping point is likely to occur.

Samira Agnihotri

Title – Quantifying vocal mimicry in the Greater Racket-tailed Drongo: A comparison of automated methods and human assessment. (15 min)

Abstract

A fundamental part of any study on avian vocal mimicry is the objective identification and description of mimicked calls, but very few studies have adopted a quantitative approach to address this. We used spectral feature representations commonly used in human speech analysis in combination with various distance metrics to distinguish between mimicked and non-mimicked calls of the greater racket-tailed drongo, Dicrurus paradiseus and cross validated the results with human assessment of spectral similarity. We found that the automated method and human subjects performed similarly in terms of the overall number of correct matches of mimicked calls to putative model calls. However, the two methods also misclassified different subsets of calls and we achieved a maximum accuracy of ninety five per cent only when we combined the results of both the methods. This study is the first to use algorithms normally used in human speech recognition to quantify vocal mimicry. Our findings also suggest that in spite of several advances in automated methods of song analysis, corresponding cross validation by humans remains essential.

Sandeep Pulla

Title – Tree niche differentiation in a tropical forest. (30 min)

Abstracts

Theory predicts that species occupying identical niches cannot coexist. Yet, high levels of alpha diversity are observed in tropical forest trees, all of which apparently require the same set of resources. Evidence that plants in natural communities are segregated along spatial gradients of light, water, and nutrients is growing, but far from conclusive. Furthermore, environmental heterogeneity resulting from, say, inter-annual rainfall variability, creates opportunities for temporal niches. I discuss the evidence for tree niche differentiation along resource gradients in space and time using long-term data from a seasonally dry tropical forest in southern India.

Sanjeeta Sharma Pokharel

Title – Assessing stress response in Asian Elephants using fecal glucocorticoid metabolites. (15 min)

Abstract

Various human-induced and ecological stressors like native habitat shrinking due to rapid expansion of human population and low availability of resources results in chronic stress in animals .In order to cope with adverse conditions, body secretes glucocorticoid which mobilizes energy in response to stressors. But as the adversities increase, resultant chronic stress elevates the glucocorticoid levels , which can cause reproductive inhibition, immune system suppression, neuronal death and impaired cognitive function. Though, the effects of environmental disturbances are difficult to establish in the slowly reproducing long lived species like elephants, it can be analyzed by measuring the levels of cortisol/ corticosterone in blood plasma, saliva, urine or feces. Invasive techniques like blood sampling, in itself, increases the level of cortisol/ corticosterone which in turn influences the result. Recent studies have proven that the non-invasive assessment of adrenocortical function is more efficient and helpful than the invasive one. The proposed study on Asian elephants attempts to assess the long-term effects of stress using the non-invasive technique i.e. fecal Glucocorticoid Metabolites. The study will, hence, characterize the pattern of glucocorticoid metabolites concentration (using a validated enzyme immunoassay (EIA)) in free-ranging and captive Asian elephants based on ecological pressures like seasonality, body condition and crop-raiding vs. non-crop-raiding elephants. In addition, this study aims to analyze the effect of external and internal variables (age, sex, diet, external environment, etc) which may not be related to the endocrine status of an individual but has influence on the actual hormone concentration.

Souvik Mandal

Title – How far do wasps fly? (15 min)

Abstract

Ropalidia marginata is a primitively eusocial, independent founding, polistine wasp widely distributed in peninsular India. Although we have a fair amount of information about its nesting biology and social organization, we know little about its abilities and mechanisms of orientation, navigation and homing. In an attempt to understand how far the wasps fly, we removed and transported foragers from 4 nests, without giving them a view of the surroundings, and released them in 4 cardinal directions, in gradually increasing distances from the nests. Only foragers were used for the experiment because they were already observed to fly out and successfully return to their nests. All wasps (43/43 wasps and a total of 198/198 releases) successfully returned to their nests when they were released within an area of about one sq. km around their nests. We also released 125 wasps beyond an area of one sq. km around their nests but within four sq. km around their nests. Here the wasps returned sometimes but not always: of the 243 releases, wasps returned only in 140 cases. No wasps (0/64 wasps) returned to their nests when they were released beyond four sq. km around their nests. In another experiment, when all wasps, including foragers and non-foragers were released at a point 100 meters away from their nests, only some (38/64 wasps) successfully returned to their nests, even when they were given a view of their surroundings during transportation. In this experiment, the probability that a wasp returned to her nest was positively correlated with the proportion of time that she had spent away from her nest prior to the experiment. These results are consistent with the hypothesis that familiarity with the surroundings is both necessary and sufficient for the wasps to perform successful homing.

Suman Attiwilli

Title- Impact of invasive plant Lantana camara and road on habitat use by butterflies in a moist deciduous forest. (15 min)

Abstract

Dr. Sumanta Bagchi

Title – Empirical signatures of ecological resilience. (15 min)

Abstract

Characterization and prediction of dynamics in natural communities remains a fundamental challenge in ecology. Communities and ecosystems have long been known to show abrupt directional shift, transient and reversible change, apparent nondirectional drift, as well as relative stability through time. Such behaviors are expressions of ecological resilience. But, our ability to recognize their empirical signatures in real-world ecological data, and the timescales associated with different behaviors, remains inadequate. We propose a correspondence between the four major types of community dynamics and properties of animal movement: dispersal, migration, nomadism, and residence respectively. We test this idea using available long-term vegetation records. This approach provides opportunities to interpret ecosystem dynamics and refine guidelines for natural resource managers.

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