CES In-House Symposium (10th and 11th January 2008)

Abstract book

Ecology Students’ Society

Indian Institute of Science Bangalore 560012

India

Behavioural Biology and Ecology

Possible novel functions of dominance behaviour (aggression) in the primitively eusocial wasp, Ropalidia marginata Prof. Raghavendra Gadagkar E-mail id: ragh@ces.iisc.ernet.in Abstract not received.

Behavioural Biology and Ecology Even babies can count!

Anindita Bhadra E-mail id: abhadra@ces.iisc.ernet.in

Recent studies on infant cognition have shown that infants have the ability to make simple arithmetic operations for numbers less than four. Studies on some primates have also corroborated these results. These studies show that the ability to count is not restricted by the ability to use language and symbols, and that the concept of numbers is not unique to the "human" mind.

Behavioural Biology and Ecology

Novelties In Breeding Behaviour Of Endemic Anurans Of The Western Ghats

Gururaja K. V. E-mail id: gururaj@ces.iisc.ernet.in Amphibians are known for the duality in their lifecycle, a free living tadpole stage in water and an adult stage on land. Breeding starts in amphibians with the on set of monsoon in the Western Ghats. This generally involves, advertisement calls from male to which female responds. Subsequently, male mounts on female (amplexus) and entire process terminates with oviposition. But some amphibians exhibit bizarre patterns in reproduction and development that they question the very definition of duality in amphibians. And some provide greater insight into breeding behavior, biogeography and evolution. Such novelties are expressed in their calls, courtship displays, amplexus, oviposition site selection, oviposition and post-oviposition activities. Direct development, cephalic amplexus and arboreal/ceiling oviposition are few interesting behaviours dealt in this presentation.

Behavioural Biology and Ecology

Transition of an aggressive potential queen to a docile queen in the primitively eusocial wasp, Ropalidia marginata Aniruddha Mitra E-mail id: aniruddha@ces.iisc.ernet.in Ropalidia marginata is a primitively eusocial paper wasp widely distributed in peninsular India. Colonies comprise of a queen who monopolizes reproduction, and several other females functioning as sterile workers. It is similar to other primitively eusocial species in the absence of morphological difference between queen and workers. Yet unlike other such species, R. marginata queens are remarkably docile in behaviour, which is a characteristic of highly eusocial species. An interesting fact is that when such a docile queen is removed from the colony, one of the remaining individuals emerges as the potential queen, becomes very aggressive and goes on to become the next queen. This suggests that R. marginata potential queens may use dominance to suppress worker reproduction, and later on use some other mechanism, possibly pheromones, once they develop their ovaries and become established as queens. Thus, this system provides a unique model to study the shift in control of worker reproduction from physical inhibition by queen to pheromonal queen signal. We hypothesise therefore, that there should be a negative correlation between dominance behaviour and ovarian development of potential queens. In the present study we provide evidence in support of this hypothesis. In future studies, we propose to also measure the development of pheromonal signal by potential queens. Such studies, in addition to giving evidence for transition in the nature of regulation of worker reproduction from physical control to pheromonal signalling, will also give clues regarding evolution of primitively eusocial to highly eusocial state in general.

Behavioural Biology and Ecology

Suppression of mite reproduction by Apis cerana Jessica Burtness University of Minnesota, USA (Visiting student at Prof. Raghavendra Gadagkar’s Lab.) E-mail id: burt0144@unm.edu, jessica@ces.iisc.ernet.in A parasitic mite (Varroa destructor) causes millions of dollars in damages to Western honey bee colonies (Apis mellifera) every year in the United States and Europe. The mite reproduces on developing honeybee pupae, thereby weakening individual bees and transmitting viruses. The original host of the mite is the Asian honey bee (Apis cerana), which has several traits that make it mite-resistant. One interesting and effective trait is restriction of mite reproduction to male pupae. On A. mellifera, the mite reproduces on both male and female pupae, allowing the mite population to rapidly increase. I am interested in learning whether it is a physical trait of the female pupae or behavior by adult workers that restricts mite reproduction in A. cerana. I will introduce mites onto developing female A. cerana pupae and check for removal by adult bees. I will also measure mite reproduction on female pupae in the absence of removal. The results will help us continue to breed for mite resistance in A. mellifera.

Behavioural Biology and Ecology Floral mimicry and camouflage: a study in visual ecology of crab spiders (Thomisus sp.) Ramachandra M Bhaskara, Brijesh C M, Saveer Ahamed, Renee M Borges E-mail id: bhaskararamachandra@yahoo.com Mimicry can be protective or aggressive. Both forms aid the organisms to achieve crypsis. Camouflage, in which a species appears similar to its surroundings, is essentially a form of visual mimicry, but usually is restricted to cases where the model is non-living or abiotic. Though mimicry is most obvious to humans in visual mimics, others senses such as olfaction (smell) or hearing may be involved, and more than one type of signal may be employed. Mimicry lies in the eyes of the beholder. In floral mimicry the model is the flower. Floral mimicry in many cases is used as a tool to overcome the sensory biases of the predators or prey. Crab spiders are ambush predators and use aggressive mimicry to ambush butterflies, bees, flies, and other flower visitors. Their venoms enable them to successfully attack insects much larger than themselves. Here we examine the basis of floral mimicry in crab spiders (Thomisus sp) on Spathiphyllum plants. Since the selection pressure for the colouration of the Crab spiders is driven by the sensory biases of the prey, we also examined the spider and plant part colouration using hymenopteran visual system. The Spathiphyllum plant is a neo-tropical species. The presence of old-world crab spiders on these plants indicates that these spiders actively select their hunting sites. What are the cues which govern the selection of a hunting site by these spiders? (Visual /olfaction) we examined the role of UV light in the spider’s choice of hunting sites and found that the spiders have a sense of UV perception and use it to enhance prey capture by choosing non-UV reflecting surfaces preferentially.

Behavioural Biology and Ecology

Finding an appropriate index to construct dominance hierarchies in the primitively eusocial wasps, Ropalidia marginata and Ropalidia cyathiformis Alok Bang E-mail id: alok@ces.iisc.ernet.in There is a vast diversity in methods of computation of dominance ranks in behavioural literature, but rarely the rationale behind using a particular index has been explained. In this study, we analyzed three dominance indices, viz. Index of Dominance (DI), Clutton-Brock et al.’s index (CBI) and David’s Score (DS). Apart from DI that is proposed by our group to calculate dominance ranks in Ropalidia marginata and Ropalidia cyathiformis, primitively eusocial paper wasps, the other two indices were chosen based on popularity and recommendations by other groups. Dominance ranks obtained from the behavioural data were subjected to correlation analysis and later, the indices were evaluated based on the number of unique ranks (ranks without ties) they attributed. We found that the three indices attributed similar ranks; however, DI gave significantly more number of unique ranks. Using artificial data sets, each index was later tested on two factors, viz. non-interacting pairs and reversals. The three indices attributed similar ranks for artificial data sets with varying percentages of non-interacting pairs or pairs showing reversals. The numbers of unique ranks given by the three indices were not significantly different except that at high percentage of non-interacting pairs, DI emerged as the best index, whereas at higher reversal rates, DS seemed to be a better index. Our results, thus, show that the choice of index to be used should be decided depending on the properties of the index as well as the social structure and interaction network of the species to which it is applied.

Behavioural Biology and Ecology

Host-locating mechanisms in fig wasp nematodes Anusha Krishnan E-mail id: anusha@ces.iisc.ernet.in The association between insects and nematodes make up a significant section of all interspecific interactions in a large variety of ecosystems, with insects often forming "mobile microhabitats" for nematodes to inhabit. Earlier studies have reported the association of nematodes with several species of figs and their pollinators. Observations on the nematode and the pollinator wasps indicate that the nematode enters the fig syconium with female pollinators. Once there, it lays its eggs and develops alongside the fig wasps. The emergence of the female pollinators and the nematodes are highly correlated, and the cycle is repeated, with the nematodes entering the female pollinators' abdomens to be carried to a new fig syconium. While the kind of association that exists between the nematodes found in the fig Ficus racemosa and its fig wasps has not yet been classified, these nematodes have been found within the female pollinators (Ceratosolen fusciceps) for a part of their life cycle. Within a fig syconium, eclosion of wasps of several species (pollinators and non-pollinators) occur around the same time. Therefore, the interior of the syconium is a very crowded area occupied by males and females of several species of fig wasps. The nematode, however, needs to detect and home-in on female pollinator wasps, as it is only these wasps that can carry the nematodes into another fig syconium. This study was designed to investigate the mechanisms by which nematodes detect their appropriate hosts, ie, the female pollinator wasps. We show here that the nematodes use volatile and cuticular hydrocarbon cues to locate female pollinators. The study indicates that the nematodes use volatile and cuticular hydrocarbon cues to distinguish between female pollinators and female non-pollinators, while volatile cues seem to be more important for them to distinguish between male and female pollinators.

Behavioural Biology and Ecology

Comparative analysis of sexual selection in mammals and birds Dr. Kavita Isvaran E-mail id: kavita@ces.iisc.ernet.in Sexual selection is recognised as a strong evolutionary force with consequences for the evolution of diverse morphological, behavioural and life history traits. What predicts the degree of sexual selection in a population? Till recently, genetic studies of paternity and maternity in mammals were too few to allow systematic investigations of patterns of reproductive success in mammals. In this talk, I explore variation in the potential for sexual selection on males in different species of mammals and birds. I discuss the effects of social mating system and covert mating tactics on the potential for sexual selection in a population. Findings indicate an interesting role for extra-pair mating tactics and the ecological conditions influencing the opportunity for such covert tactics are explored. I also discuss the consequences of variation among species in sexual selection for the evolution of adult lifespans, an important life history trait.

Evolution

A re-look at group selection, with special reference to the cellular slime moulds Prof. Vidyanand Nanjundiah E-mail id: vidya@ces.iisc.ernet.in As so much else in biological thought, the levels of selection debate was initiated by Darwin. It has continued ever since, with the protagonists arguing vehemently in favour of 'their' level. The debate keeps getting settled every now and then, but not in the same way. This is a pointer to many things. The first is that there may be a certain degree of confusion in the field - here, between phenomena and explanatory concepts. (Often, though not always, the culprit is language.) The second is a lack of appreciation of the distinction between explanations that are necessary, sufficient, or both necessary and sufficient. The third follows from these two: each of the conflicting opinions on levels of selection may be valid within its own realm of applicability. As far as the notion of group selection goes, the central issue is whether it is meaningful to talk of group-level adaptations. After sketching the points just made, I will try to make a case for the existence of group-level traits, and therefore of group-level adaptations, in the cellular slime moulds.

Evolution Exploitation and co-existence in social groups of the cellular slime moulds Santosh Sathe1, Bandhana Katoch2, Ramesh K Aggarwal3, James Cavender4 and Vidyanand Nanjundiah1, 2

1Centre for Ecological Sciences, Indian Institute of Science, Bangalore 560 012, India. 2Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560 012, India. 3Centre for Cellular and Molecular Biology, Hyderabad 500 007, India. 4Department of Environmental and Plant Biology, Ohio University, Ohio 45701, U.S.A. E-mail id: santosh_sathe@ces.iisc.ernet.in Cellular slime mould (CSM) amoebae organise themselves into aggregates in which some cells die (and form a stalk – equivalent to somatic tissue) whereas others survive (and form spores – equivalent to a germ line or reproductive tissue). This provides an extreme example of so called ‘altruistic’ and ‘selfish’ behaviour within a social group. We have been working with CSM isolates, isolated from undisturbed forest soil. A molecular phylogeny based on small subunit ribosomal RNA (SSU rDNA) partial gene sequences from 17 wild isolates belonging to 5 species and four isolates from three laboratory strains indicates their pattern of relatedness. The experiments reported below were carried out with genetically distinguishable strains of Dictyostelium giganteum, with the F1 progenies of a cross between two strains, or with a parent-offspring combination. Strains intermingle freely in the laboratory. In other words, they can form chimeric aggregates After they do so, one strain often exploits the other during sporulation; that is, it forms a disproportionate number of spores relative to the other. Further there is a hierarchy in relative spore forming abilities of these strains. However the strains co-exist in close proximity in the wild; one assumes that the co-existence is not a transient phenomenon. We have begun to address questions that are raised by this observation. 1) What might account for the co-existence of different strains of same species even when one is more efficient at sporulating than the other in a chimera? 2) How do group-level traits such as aggregation territory size, overall spore forming efficiency and strain productivity compare between clonal and chimeric groups? Our preliminary findings are as follows: (a) There is a trade-off between different life cycle components of fitness, which may help two strains to co-exist; (b) With respect to territory size and spore forming efficiency, but not individual strain productivity, clonal groups and chimaeras are comparable; (c) The maintenance of ‘altruistic’ behaviour in a social group may depend on other factors besides the average level of genetic similarity between group members. Reference: Kaushik S, Katoch B, Nanjundiah V (2006) Social behaviour in genetically

heterogeneous groups of Dictyostelium giganteum. Behav Ecol Sociobiol 59: 521-530.

Evolution Karyotypic evolution and selection strategies in nasuta-albomicans complex of Drosophila

Dr. M. C. Shilpa E-mail id: shilpa@ces.iisc.ernet.in

Hybridization leads to the incorporation of genes of one species into the gene pool of another. Considering the importance of hybridization in evolution, to study the events that promotes differentiation of gene pools followed by introgression, nasuta-albomicans complex was established by taking the advantage of the cross fertility between Drosophila nasuta nasuta and D. n. albomicans. Interracial hybridization under laboratory conditions between D. n. nasuta and D. n. albomicans has lead to the introgression of their genomes and has resulted in the evolution of new karyotypic races called Cytoraces. In each of the new Cytorace, chromosomes of D. n. nasuta and D. n. albomicans are represented in different combinations in different Cytoraces. The karyotypic composition of thirty such Cytoraces will be discussed with reference to evolutionary strategies effect in different components of the evolving karyotypes.

Evolution Primate Numts and reticulate evolution of capped and golden leaf monkeys (Primates: Colobinae) Dr. Praveen Karanth E-mail id: karanth@ces.iisc.ernet.in

Recent phylogenetic study of langurs and leaf monkeys of South Asia suggested a reticulate evolution of capped and golden leaf monkeys through ancient hybridization between Semnopithecus and Trachypithecus. To test this hybridization scenario I have analyzed nuclear copies of mitochondrial cytochrome b gene (numts) from capped, golden and Phayre’s leaf monkeys. These numts were aligned with mitochondrial cytochrome b sequences of various species in the genera Semnopithecus and Trachypithecus. In the phylogenetic tree derived from this alignment, the numts fell into three distinct clades (A, B, and C) suggesting three independent integration events. Clade A was basal to Semnopithecus and clades B and C were basal to Trachypithecus. Among the numts in clades A and C were sequences derived from species not represented in their respective sister mitochondrial groups. This unusual placement of certain numts is taken as a strong support for the hybridization scenario. Based on the molecular dating of these integration events, hybridization is estimated to have occurred between 3.7 and 6.4 million years ago. Capped and golden leaf monkeys might have to be assign to a new genus to reconcile their unique evolutionary history. Additionally northeast India appears to be a “hot spot” for lineages that might have evolved through reticulate evolution.

Evolution Comparative population genetic structure of three Hemidactylus geckos Rohini Bansal E-mail id: rohini_bansal@ces.iisc.ernet.in Hemidactylus species, is one of the most diverse and most widely distributed group of reptiles in the world. Genus Hemidactylus constitutes of 80 species around the world of which 18 species are found in India. There is a wide range of habitats that are inhabited by Hemidactylus species. The most commonly known species of Hemidactylus is H. brookii that resides in human habitations and is found both inside and outside their houses. On the other hand, some of these species have a continuous distribution outside the human habitations while rest are habitat specialists. Because of this variability in the degree of association with human beings, their population structure are likely to show difference owing to the variations to the agents limiting the gene flow amongst their populations. In case of commensal species, the human transport might act as a potential agent for gene flow amongst its populations. Whereas, in case of habitat specialists, there might be very less or no gene flow amongst the populations. Based on the variations in the habitat preferences and different degrees of their commensalisms with humans, I am studying the population genetic structure of three closely related species of Hemidactylus geckos.

Evolution

Characterising morphological variations of Hanuman langurs (Semnopithecus entellus) of Peninsular India

Chetan Nag E-mail id: chetan@ces.iisc.ernet.in

Hanuman langurs are one of the well-known and revered non-human primates in India, and they have long been a taxonomic nightmare. Existing classification schemes of Hanuman langurs are inconsistent with each other and there is much disagreement in the literature on the subspecies or species status of various populations of the Hanuman langurs. The same population has been assigned to different species/subspecies with very different distributional range by various authors. Most recent classification schemes have been based on reanalysis of existing museum specimens collected in the first half of last century or earlier or reinterpretation of earlier work. Thus no new material from the field has been used in most of these studies.

In the present work an objective analysis of morphological characters using appropriate statistical tool was undertaken in order to resolve the underlying problem of Identification of langurs in different parts of Karnataka. Data were collected on external morphological characters, like coat color, blackness of hands, presence or absence of crest etc., from various Hanuman langur populations in the field throughout Karnataka. This data was subjected to statistical analyses to objectively identify distinct “morphotypes” in order to address questions pertaining to number of morphotypes and their diagnostic characters with respect to state of Karnataka. Results indicate that there are at least four distinct morphotypes of so-called Hanuman langurs in Karnataka. Implications of this result on the various classification schemes is also discussed.

Plant-Animal Interactions

Factors influencing fruit removal of an economically valuable tree in dry tropical forests of Mudumalai Soumya Prasad E-mail id: soumya@ces.iisc.ernet.in

In animal-dispersed species, all fruiting individuals in a population are not equally attractive to frugivores. Understanding what influences frugivore choice is a critical step linking frugivore behaviour with plant demography. For tropical forest fruits that are harvested by people, understanding quantities of fruits removed by frugivores and what influences their choice is vital to develop ecologically sustainable practices of harvest. Fruits of Phyllanthus emblica Linn., (Euphorbiaceae), a tree common in dry tropical forests of south Asia, are important non-timber forest produce. Its fruits are dispersed primarily by ruminants (chital, barking deer, mouse deer) aided by colobine monkeys (langurs). Langurs drop fruits under the parent tree itself, but make fruits accessible to terrestrial frugivores like ruminants. Ruminants swallow fruits whole and regurgitate seeds intact after retaining them in the rumen for several hours (Prasad et al. 2006). Fruit quantity and densities of fruiting neighbours are two factors that have been shown to explain among-plant variability in fruit removal in several field studies (Garcia et al. 2001, Saracco et al. 2005). Fruiting P. emblica trees representing the range of fruit crop sizes and densities of fruiting resources (both conspecific and heterospecific) available at the site were monitored for fruit removal at the 50 ha plot in Mudumalai during two consequtive fruiting seasons (2005-07). Generalized linear models and mixed-effect models were used to explore the relationships between fruit crop size, fruiting neighbourhood densities and fruit removal. Intra-specific competition between trees for frugivores appears to be the driving factor during the high fruiting year. In the low fruiting year, competition between frugivores for fruiting resources appears to mould this fruit-frugivore interaction. This analyses suggests that inter-annual variability in fruit crop size has important consequences for fruit-frugivore interactions. References: García, Daniel, Zamora, Regino, Gómez, José M. & Hódar, José A. 2001. Frugivory at

Juniperus communis depends more on population characteristics than on individual attributes. Journal of Ecology 89 (4), 639-647.

Prasad, S., R. Chellam, J. Krishnaswamy, and S. P. Goyal. 2006. Ruminant-mediated seed dispersal of an economically valuable tree in Indian dry forests. Biotropica.38 (5):679 – 682

Saracco, James F., Collazo, Jaime A., Groom, Martha J. & Carlo, Tomás A. (2005) Crop Size and Fruit Neighborhood Effects on Bird Visitation to Fruiting Schefflera morototoni Trees in Puerto Rico

Plant-Animal Interactions Eavesdropping ants in an obligate insect-plant mutualism Yuvaraj Ranganathan and Renee M. Borges E-mail: fig@ces.iisc.ernet.in Ficus racemosa, a monoecious fig species, is patrolled by several ant species such as Oecophylla smaragdina (Formicinae), Technomyrmex albipes (Dolichoderinae) and Myrmicaria brunnea (Myrmicinae). We examined the variation in volatile signature along the F. racemosa syconium developmental cycle. At particular developmental phases of the fig syconia, mass arrival and exodus of fig wasps occur. We investigated whether ants are able to eavesdrop on the chemical communication between the figs and their pollinating fig-wasps and use this information to their own advantage to localize fig wasps (pollinators and parasites) as prey. We conducted behavioural assays using a Y-shaped glass olfactometer to test whether ants are able to respond to volatiles from different developmental phases of fig syconia, and thus whether the ants could use these volatiles as cues for prey location. We also tested the response of ants to volatiles emanating from the fig wasps themselves. We found that each ant species responded differently to the test volatiles and that the response was concentration-dependent. Non-predatory and homopteran-tending ants did not respond to fig or wasp volatiles. Furthermore, predatory ants nesting in and patrolling non-fig trees did not respond to fig or wasp volatiles. This indicates that ant response to fig and wasp volatiles is a learnt behaviour. Based on their biology, some ant species are more effective fig wasp predators and can form interactions with fig trees of varied benefits to the tree depending on whether pollinating or parasitic wasps are preferentially preyed upon.

Plant-Animal Interactions The chemical ecology of seed dispersal in monoecious and dioecious figs Renee M. Borges

E-mail id: renee@ces.iisc.ernet.in In the nursery pollination system of figs (Ficus, Moraceae), flower-bearing receptacles called syconia breed pollinating wasps and are units of both pollination and seed dispersal. Pollinators and mammalian seed dispersers are attracted to syconia by volatile organic compounds (VOCs). In monoecious figs, syconia produce both wasps and seeds, while in (gyno) dioecious figs, male (gall) fig trees produce wasps, and female (seed) fig trees produce seeds. VOCs were collected using dynamic headspace adsorption methods on freshly collected figs from different trees using Super Q® collection traps. VOC profiles were determined using gas chromatography-mass spectrometry (GC-MS). The VOC profile of receptive and dispersal phase figs were clearly different only in the dioecious mammal-dispersed Ficus hispida but not in dioecious bird-dispersed F.exasperata and monoecious bird-dispersed F. tsjahela. The VOC profile of dispersal phase female figs was clearly different from that of male figs only in F. hispida but not in F. exasperata, as predicted from the phenology of syconium production which only in F. hispida overlaps between male and female trees. Greater difference in VOC profile in F. hispida might ensure preferential removal of seed figs by dispersal agents when gall figs are simultaneously available. The VOC profile of only mammal-dispersed female figs of F. hispida had high levels of fatty acid derivatives such as amyl-acetates and 2-heptanone, while monoterpenes, sesquiterpenes and shikimic acid derivatives were predominant in the other syconial types. A bird- and mammal-repellent compound methyl anthranilate occurred only in gall figs of both dioecious species, as expected, since gall figs containing wasp pollinators should not be consumed by dispersal agents.

Plant-Animal Interactions

The role of domatia in the interaction of the ant-plant Humboldtia brunonis with its invertebrate associates Joyshree Chanam E-mail id: joy@ces.iisc.ernet.in This is a brief description of the work plan for my study on the semi-myrmecophyte Humboldtia brunonis (Fabaceae). This understorey tree, endemic to the Western Ghats, is polymorphic for the presence of domatia, with some plants in the population bearing domatia while others do not. Domatia in this species are swollen hollow internodes which house protective as well as non-protective ants besides a large diversity of non-formicid invertebrates. The plant also provides extrafloral nectar (EFN) containing sugars and amino acids to ants from nectaries borne on young leaves. We would like to determine if there is any geographic variation in the propensity for domatia formation, and whether the abundance of domatia at a site affects herbivory. Since domatia provide housing for ants in which brood is reared, we will also investigate the existence of trophic interactions between the plant and its invertebrate associates (especially ants), using stable isotope analyses. Using this technique, we will ask whether plants acquire nitrogen from their resident invertebrates by absorbing this nutrient from the domatia, and how much carbon is acquired by the ants from EFN. Since ants also feed on plant-based resources via honeydew from Homoptera that they tend on plants, we will also investigate the role of Homoptera in this trophic interaction, and determine how the presence of domatia affects this interaction.

Plant-Animal Interactions Comparative longevity in a fig wasp community Mahua Ghara and Renee M. Borges

E-mail id: mahua@ces.iisc.ernet.in The fig-fig wasp system is a well known example of mutualism and parasitism. Figs (Moraceae: Ficus spp.) harbour developing pollinators and parasites (Hymenoptera: Agaonidae) in an urn-shaped receptacle called a syconium whose development from pollination to seed dispersal may last several months. The syconium is lined by flowers, which are used as oviposition sites by pollinators and parasitic gallers. The pollinators and the parasites comprise the fig wasp community. Pollinators are gallers, pro-ovigenic, short-lived (1–2 days), enter the syconium and die inside after pollination and oviposition. The parasites can be gallers, inquilines, parasitoids or hyperparasitoids, pro- or syn-ovigenic, short to long-lived, and oviposit into multiple syconia from the exterior using long ovipositors. The various wasp species oviposit at different developmental stages of the syconium, yet their progeny exit at the same time. Thus, the fig wasp community is a multitrophic interaction system, in which the community members may not only be partitioned with relation to oviposition sites but also differ in longevity to meet the searching requirements for their specific hosts. Therefore, a study of the comparative longevity of the fig wasp community of Ficus racemosa Linn. (Section: Sycomorus) from southern India was undertaken under laboratory conditions to relate longevity to wasp biology. This community consists of the pollinating galler (Ceratosolen fusciceps Mayr), 4 parasitic putative gallers (Apocryptophagus spp.) and 2 parasitoids (Apocrypta spp.). These were fed on combinations of water and sucrose solutions and their longevity was compared to untreated controls. Their ovigeny was also investigated. Body size was measured as a correlate of longevity. The duration of the developing stages of the syconium used by the parasites for oviposition was also recorded. The results indicated that the syn-ovigenic parasitoids Apocrypta spp. live longer than the pro-ovigenic putative galler species. However the correlation between longevity and body size did not show any consistent results. Longevity of the parasitoids increased nearly three-fold in the sucrose treatment. Based on these results, it is possible that parasitoids feed on carbohydrate sources in the wild (honeydew or nectar), thereby increasing their longevity. Ovipositing parasitoids were generally present across most developing stages of the syconium. Thus, with increased longevity and presence across more developing stages of the syconium, parasitoids may be able to parasitize most other community members and also control their population using a top down approach in this multitrophic interaction system.

Ecosystem dynamics

The resilience of tropical dry forests to disturbance and climatic variability: a 16-year study of a large-scale plot at Mudumalai, Southern India Sukumar, R., Dattaraja, H.S., Suresh, H.S. Centre for Ecological Sciences, Indian Institute of Science, Bangalore 560012, India E-mail id: rsuku@ces.iisc.ernet.in The structure and stability of tropical forests and their role in the carbon cycle are being investigated, especially in the context of future climate change. We have been studying forest structure and dynamics in a 50-ha permanent plot in a tropical dry forest at Mudumalai, Southern India. During the period 1988-2004, this site has witnessed six ground fires, a severe drought during 2001-03, and significant mortality in understory trees because of fire and herbivory by elephants. Recruitment, mortality and population size of woody stems (> 1cm> dbh) have fluctuated widely, depending mainly on occurrence of fire. Basal area increased overall from 24.4 m2/ha in 1988 to 25.3 m2/ha during 2004, though there were marginal declines during periods of deficient rainfall. Interestingly, there has been a monotonous increase in above-ground biomass (and carbon stocks) from 174 tons/ha in 1988 to 193 tons/ha in 2004, mainly because of a shift in biomass from species with low wood density to those with high wood density, suggesting that this dry forest has sequestered carbon in spite of disturbance and extreme climate. We suggest that tropical dry forests subject to a regime of disturbance and high environmental variability have adapted through a variety of life-historical traits, and thus show high resilience, an important consideration in assessing future climate change impacts on tropical ecosystems.

Ecosystem dynamics

Tree species diversity and dynamics across a rainfall gradient in Mudumalai Wildlife sanctuary - Southern India

H. S. Dattaraja E-mail id: dattaraj@ces.iisc.ernet.in The species richness and diversity in tropical forests have been well documented. A study was conducted to understand the species diversity in Mudumalai wild life sanctuary. The aim was to describe and compare relationships among plots using vegetation data with the environmental data. A series of 19 permanent 1 ha plots were established along east (dry) to west (wet) direction. The important components of the ecosystem such as vegetation and climatic factors were analyzed by multivariate methods. Statistically significant correlation was observed among structural and floristic diversity with precipitation and fire frequency. The structural and floristic richness increased along the precipitation gradient. However, the recurring fires in this region had direct influence on the species distribution and richness. We have been studying all 19 plots to understand long-term dynamics of above heterogeneous sites since its establishment (1994-95). We examine the basic aspects of population dynamics including changes in species population, growth, survival and causes of mortality across moisture gradient.

Ecosystem dynamics

Impact of climate change on Indian forests: A short term and medium term assessment Rajiv Chaturvedi E-mail id: rajiv@ces.iisc.ernet.in Global assessments have shown that future climate change is likely to significantly impact forest ecosystems. Long term assessment of the impact of Climate change on Indian forest ecosystems are available. However, due to lack of regional climate projections for short and medium terms, such estimates are not available for these intermediate time periods. The present study makes an assessment of the impact of projected climate change on Indian forest ecosystems for the years 2020 and 2050. The assessment is based on climate projections of General Circulation Model of the Hadley centre (HadCM3) using A2 (740 ppm CO2) and B2 (575 ppm CO2) scenarios of Special Report on Emission Scenarios of IPCC and the BIOME4 vegetation response model. The paper assesses likely change in Net primary productivity and forest types over the grid sizes of 3.75 * 2.5 degrees across India.

Ecosystem dynamics

Aliens! Theories of invasion and an overview of Lantana camara in tropical forests Geetha Ramaswami E-mail id: geetha_r@ces.iisc.ernet.in In the current era of global change, one of the most imminent of all dangers seems to be the homogenization of biological diversity. With the effect that more and more organisms are now being found in geographical locations in which they were historically unknown, and are increasingly becoming a threat to the existing diversity. Several theories have been put forward to explain the success of non-native species in areas that they colonize, like: Evolution of Increased Competitive Ability (EICA), Novel Weapon Hypothesis (NWH), Resource Limitation Hypothesis amongst others. In spite of several of these hypotheses being put to rigorous tests, it is still extremely difficult to attribute all observed characteristics of an invasive to any one theory. Lantana camara is a plant of Central and South American origin, which has gained notoriety as one of the most invasive of tropical plants in Asia, Africa and Australia. L. camara has been credited with formidable allelopathic arsenal and has for long been the nemesis of forest authorities, as the seven headed hydra of dry forests. I plan to study the impact of Lantana on environmental and biological aspects of a dry deciduous forest ecosystem, and eventually build a model for predicting future distributions of the plant in a changing climate scenario.

Ecosystem dynamics

Clean development mechanism and forestry sector in India Indu K. Murthy E-mail id: indu@ces.iisc.ernet.in Forestry is broadly included under ‘Land Use Land-Use Change and Forestry’ (LULUCF) sector in the Climate Convention. Afforestation and re forestation projects have been included under the Clean Development Mechanism (CDM) of the Kyoto Protocol. Given that India has vast extent of degraded or wastelands, which are unlikely to be afforested under the current afforestation programmes, there have been efforts to do forestry projects under CDM. However, there are issues such as establishing baseline, leakage, and additionality, which makes forestry projects under CDM a complex effort. However, forestry projects have immense co-benefits such as biodiversity conservation, enhanced participation of all stakeholders, watershed protection and ultimately sustainable development, which is also the ultimate goal of the Climate Convention, which makes forestry and CDM an area to be explored.

Macroecology and Biogeography

A global comparison of mixed-species bird flocks Hari Sridhar E-mail id: hari@ces.iisc.ernet.in Mixed-species bird flocks (flocks hereafter) occur in forested habitats all over the world. These groups, of mostly insectivorous species, are thought to form either for anti-predatory or/and foraging benefits. In this talk, I attempt to synthesize what is known about flocks world-over. I examine variation in flock richness, size, and composition, and in species’ propensity to flock across the globe. I also describe features which are common to bird species which lead flocks (nuclear species). Finally, I discuss the advantages of using comparative analyses in understanding the how and why of mixed-species bird flocking.

Macroecology and Biogeography Comparative phylogeography of Scolopendrids (Class: Chilopoda) of peninsular India Jahnavi Joshi E-mail id: jahnavi@ces.iisc.ernet.in Comparative phylogeography is a sub-branch of phylogeography where geographic pattern of genetic variation among multiple co-distributed species are studied. Here I am trying to understand the role of various ecological, environmental, and physical factors that might have shaped the genetic architecture of terrestrial invertebrates, particularly in Peninsular India. I am using centipedes which are terrestrial, predatory, primitive and low dispersing arthropods as the model system for this study.

Macroecology and Biogeography

Biogeography of amphibians and reptiles of Nicobar Islands: Delimiting assemblages S.P. Vijayakumar E-mail id: vj@ces.iisc.ernet.in A historical biogeographic analysis is a three step process: recognition of spatial homology, identification of areas of endemism and hypothesis about area relationship. In this talk, I will present the results pertaining to recognition of spatial homology in the Andaman and Nicobar archipelago. Traditionally, the archipelago has been considered as a single biogeographic region with two provinces: Andaman and Nicobar. Quantitative analysis of the distribution patterns among various taxonomic groups has been hampered due to lack of island wise distribution data. Based on field data on the distribution of three taxonomic groups: frogs, lizards, and snakes from 15 islands in the Nicobar archipelago I delimit distinct herpetofaunal assemblages using parsimony analysis of distribution. The results indicate the presence of two major assemblages in the Nicobar Islands with their boundary coinciding with a deep sea channel. Bathymetric data shows that the major area clades identified in this study probably remained isolated during the last glacial maximum.

Macroecology and Biogeography

Can taxon pulse driven biotic diversification explain patterns in biogeography of anuran amphibians of Western Ghats? M. S. Chaitra E-mail id: chaitra@ces.iisc.ernet.in Historical biogeography, a major school of biogeography whichexplains episodes of allopatric speciation resulting from the formation of a geographic barrier, called vicariant speciation. With the availability of phylogenetic analysis, it has become quite easy to invoke vicariance to explain biogeographic patterns of multiple taxa/clades mirroring the history of the formation of barrier. In the mean time there are other parallel paradigms like “Taxon–Pulse” driven diversifications which have been neglected in biogeography. Taxon pulse model incorporates both dispersal and vicariance in analysis and assume that species and their adaptations arise in the centers of diversification and that distribution of taxa periodically fluctuate around a more stable continuously occupied centers. This general biotic dispersal may be interrupted by formation of barriers, producing episodes of vicariant speciation. Breakdown of those barriers produces new episodes of biotic expansions leading to next series of vicariant events. Anuran amphibians of Western Ghats comprise around 120 species with high levels of endemism. Various models like dispersal, vicariance (out of India, Into India, and Gondwana relicts) have been invoked to explain the biogeography of anurans in Western Ghats. Most of these models are taxon specific and none of these models explain biogeography of anurans in general. The anuran of Western Ghats represents clades belonging to various temporal scales in the evolutionary history. For example Micrixalidae, Nyctibatrachidae, Ranixaidae and Sooglossidae represents Jurassic–cretaceous history, Rhacophoridae represents cretaceous history, while Ranidae and Dicroglossidae have multiple colonization history after India–Eurasia collision. The temporal scales to which these clades are dated clearly demonstrate that both dispersal and vicariance have been influencing the biogeography of anurans in Western Ghats. In this study I have made an attempt to explain the present distribution patterns of anurans in Western Ghats by revisiting the taxon-pulse models using both mitochondrial and nuclear DNA phylogenies along with divergence time estimates using multiple calibration points.

Conservation Biology

Sea turtle conservation Dr. Kartik Shanker E-mail id: kshanker@ces.iisc.ernet.in In recent times, sea turtles have become flagships for conservation, with champions amongst wildlife conservationists as well as local communities. Sea turtle conservation in India by the State and non-governmental organisations is about thirty years old. These programmes can also be contrasted with national programmes such as the Government of India – United Nations Development Program (UNDP) sea turtle project which was operated from 2000 – 2002, and international instruments, such as the shrimp – turtle dispute at the WTO. What started with a conservation program by a group of dedicated individuals in Madras, and a research program by the state Forest Department at the mass nesting beaches in Orissa, has now spread to most coastal states in India. While some turtle conservation projects are still run by the respective state Forest Departments, many are run by non-governmental organisations, ranging from students to animal activists to local communities. Of particular interest is a students’ group in Madras, which has survived despite the lack of formal structure, principally due to the attraction of working with sea turtles. Of even greater interest are the fishermen of a small hamlet in Kerala, who started with a sea turtle conservation program, and thanks in part to its success, are now leaders of their community on a number of social and environmental issues. On the other hand, the very visibility of sea turtles in Orissa may have promoted the creation of a rift between diverse communities of fishermen and conservationists; and the species has, instead of being a source of pride and valued heritage, become a bone of contention in a highly polarised and politicised battle. Hence, the use of flagships can sometimes drive conservation and social change, and at others, be a detriment to both environmental and social development.

Conservation Biology Pattern, process, cause and consequences of urban growth in Bangalore Sudhira, H.S. E-mail id: hs.sudhira@gmail.com Bangalore is one of the fastest growing cities in India. With the advent and growth of IT industry, as well as numerous industries in other sectors and the onset of economic liberalisation since the early 1990s, Bangalore has taken lead in service-based industries fuelling substantial growth of the city both economically and spatially. The unplanned and uncoordinated urban growth spatially is referred to as sprawl. Sprawl is also referred to a pattern of land-use resulting in the outgrowth that engulfs along the periphery of the city. Ascribing sprawl as a pattern of land-use alone does not throw light on the underlying processes, causes and hence their consequences. In a developing country like India, where population density is high with significant urbanization rates, urban sprawl obviously cannot be characterised by pattern alone but processes, causes and their consequences. We suggest a modification to the definition of urban sprawl as the pattern of outgrowth emergent during the process of urban spatial expansion over time caused by certain externalities and a consequence of inadequate regional planning and governance. The pattern of urban sprawl is characterised by using spatial metrics on the extent of paved surface or built-up areas. The process of urban sprawl can be characterized by changes in the pattern over time, like the proportional increase in the built-up area leading to rapid urban spatial expansion. Analyzing the causes of urban spatial expansion, the externalities are modelled as agents in a geospatial environment like the location of jobs, housing, access to services and the level of economic activity. The interaction of agents and their outcomes help generate scenarios of the consequences on land-use. The sequence of patterns, processes, causes and consequences sets the research agenda. This presentation addresses the issue of urban sprawl in the Indian context with a focus on Bangalore city. We emphasise on utility of spatial planning tools in managing urban sprawl.

Conservation Biology Elephant Conservation in the Anamalai Hill Ranges of Southern India N. Baskaran1, G. Kannan2 and R. Sukumar2 1Asian Nature Conservation Foundation Innovation Centre, Institute of Science, Bangalore 560 012. 2 Centre for Ecological Sciences, Indian Institute of Science, Bangalore 560 012. E-mail id: baskar@ces.iisc.ernet.in The Anamalai landscape (5700 km2) located in the Western Ghats of southern India is one of the potential areas for the long-term conservation of the Asian elephant (Venaktaraman et al. 2002 & Leimgruber 2003). This elephant population is genetically more diverse and distinct from the much larger population further north in the Ghats. This area is also known for its rich biodiversity along a rainfall and topographic gradient that supports natural vegetation ranging from tropical montane stunted forest and grassland to lower elevation evergreen, deciduous and dry thorn forests. Through extensive field surveys we assessed elephant habitats, mapped elephant distributions, land-use patterns and corridors, estimated elephant population size and documented elephant-human conflict. We identified several barriers to the movement of elephants arising mainly from developmental activities and topographic constraints. The mean density of elephants was estimated to be ~1 elephant/km2 at a moderately skewed ratio of adult male to female (1:9). Elephant-human conflict was much higher along the eastern than the western part of the landscape, possibly due to greater fragmentation by non-forest activities, different cropping patterns and degradation of habitats. Based on our surveys and GIS analysis we make recommendations for the long-term conservation of this flagship species.

Literature Cited: Leimgruber, P, Gagnon, J.B., Wemmer, C., Kelly, D.S., Songer, M.A., and Selig, E.R.

2003. Fragmentation of Asia’s remaining wild lands: implications for Asian elephant conservation. Anim. Conserv.6: 347-358.

Venkataraman, A. B., N. V. Kumar, K. S. Varman and R. Sukumar. 2002. Conservation of

Flagship species: Prioritizing Asian Elephant (Elephas maximus) conservation units in southern India. Curr. Sci., 82, 8: 1022-1033.

Vidya, T. N. C., Fernando, P., Melnick, D. J. and Sukumar, R. 2005. Population

differentiation within and among Asian elephant (Elephas maximus) populations in southern India. Heredity 94: 71-80.