Academic

Topic: 
Test
Speaker: 
Test, Test
Date & Time: 
10 Aug 2022 - 1:00pm
Event Type: 
CES Buzz
Venue: 
CES Seminar Hall, 3rd Floor, Biological Sciences Building
Coffee/Tea: 
After the talk
Abstract:

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Speaker Bio: 
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Recent Publications of Priti Hebbar, DST-Inspire Faculty, CES

Priti, H., Gururaja, K. V., Aravind, N. A., & Ravikanth, G. (2021). Influence of microhabitat on the distribution of tadpoles of three endemic Nyctibatrachus species (Nyctibatrachidae) from the Western Ghats, India. Biotropicahttps://onlinelibrary.wiley.com/doi/10.1111/btp.12988 

Short title: Microhabitat factors influencing Nyctibatrachus tadpoles 

Topic: 
To be announced
Date & Time: 
4 Aug 2021 - 5:15pm
Event Type: 
CES Buzz
Venue: 
CES Seminar Hall, 3rd Floor, Biological Sciences Building
Coffee/Tea: 
Before the talk
Abstract:

xxxx

Topic: 
Diversity and distribution of mixed-species groups of reef fish in the Lakshadweep Islands
Speaker: 
Anne Theo, CES
Date & Time: 
30 Jun 2021 - 3:00pm
Event Type: 
Thesis Colloquium
Venue: 
MS Teams
Abstract:

Species interactions are known to shape biological communities. While antagonistic interactions like competition and predation are well known, cooperative interactions have received comparatively less attention. Mixed-species foraging behaviour is a common phenomenon seen across various taxa including fish, birds and mammals, where different species form groups and forage together. Unlike symbiotic associations, these interactions are more dynamic and include a much larger subset of species of the community. We sampled mixed-species groups (MSG) of reef fish in the Lakshadweep islands, off the west coast of India. The data was gathered over four years following a mass-bleaching event which led to massive loss of coral in Lakshadweep in 2010. Though not widely reported, we discovered that mixed-species grouping is a common occurrence in the reef ecosystem. Around 130 of the 305 commonly observed species of fish in the Lakshadweep were seen participating in groups to some extent. Using a cluster analysis on species composition, we categorised the groups that were observed in Lakshadweep into nine compositional categories, which also exhibited variation in behaviour, habitat affinity and group cohesion. We then examined variation in grouping propensity, species richness, species evenness as well as species composition across space, time and habitat for the most commonly observed compositional categories. We found that invertivores tended to form smaller attendant groups, with clear nuclear-follower relationships, and likely form for direct foraging benefits. Herbivorous fish on the other hand formed large shoaling associations indicating benefits gained from increasing group size. We found evidence of the effect of the mass-bleaching event and subsequent ecosystem recovery on the formation of some groups. Reef fish MSGs are thus important components of these ecosystems and can both affect and be impacted by reef structure and function.

Topic: 
Collective escape dynamics of blackbuck herds during predation-like events
Speaker: 
Akanksha Rathore, Indian Institute of Science, Bengaluru
Date & Time: 
21 Jun 2021 - 3:00pm
Event Type: 
Thesis Defense
Venue: 
Google Meet
Abstract:

Collective movement is a fundamental process affecting the survival and reproductive success of group-living animals. Many of the hypothesized benefits of grouping such as predation evasion and foraging efficiency require the individuals in a group to move in a coordinated way. While moving in groups, animals are not only responding to the environment but also interacting with each other. These interactions give rise to emergent collective movement and behavioural patterns. A novel aspect of emergent behaviour is that a group can exhibit properties that no individual displays on its own. 

Most studies on emergent properties of collective behaviour are conducted in controlled conditions. However, in natural settings, habitat is heterogeneous in terms of resource distribution, availability of hiding places and substrate for movement. Empirical studies have rarely investigated such fine-scale interactions (e.g. alignment, attraction among individuals) in their natural habitat. One reason for the dearth of such studies is the difficulty of data collection. Recent advances in techniques of aerial imagery allow us to observe and record such fine-scale data. For my PhD project, I studied the collective behaviour of blackbuck herds in their natural habitat. More specifically, I investigated the collective response of blackbuck herds during predation-like events. By analyzing multiple interactions among group members simultaneously, I aimed to understand the role of social interactions in shaping the collective response of blackbuck herds when faced with predation-like threats. 

First, we overcome the difficulty of observing fine-scale interactions in animal groups (in their natural habitat) by using UAVs. We recorded blackbuck herding behaviour at high spatio-temporal resolutions (30 frames per second). Using this technique we were able to record the blackbuck herd’s collective escape behaviour in the context of predation using controlled-simulated threats.

Tracking animals in the videos recorded in natural habitat is extremely difficult due to varying background and light conditions and clutter in the background. Relatively basic image processing methods and default tools don’t perform satisfactorily in such a scenario. 

Hence, we developed a machine learning method and GUI tool to extract the spatial locations and movement trajectories of all the individuals in a group from the videos recorded in natural field conditions.

Once we were able to obtain the movement trajectories from the videos, I then analysed these trajectories and interactions between individuals to explore - how the information about predatory risk spreads through a group in natural conditions. Broadly, our results suggest that transient leader-follower relationships emerge in these groups while performing the high-speed coordinated movement. Also, males and females respond differently to the threat scenario: adult females are more likely to be the response initiators whereas adult breeding males are more likely to influence the group movement during the escape response. Our results indicate that in fission-fusion groups associations are likely to last for short time scales and spatial positions of the individuals only affect their response-time (vigilance behaviour) but not their influence on the group. 

Topic: 
Can We Learn From Insect Societies?
Speaker: 
Raghavendra Gadagkar, Indian Institute of Science, Bengaluru
Date & Time: 
20 Jun 2021 - 4:00pm
Event Type: 
Online Public Talk
Venue: 
https://youtu.be/27yUMkyTbrI
Abstract:

Many insects such as ants, bees, wasps and termites organise themselves into societies with division of labour, communication, conflict, cooperation and altruism. Insect societies resemble human societies in many ways and are arguably more efficient than ours in some ways. They sustainably harvest environmental resources, engineer their environments both inside and outside their nests, practice agriculture, fight disease with a combination of individual and social immunity, organise social hunting parties, navigate their environment using terrestrial and celestial cues and majorly influence the evolutionary trajectories of other organisms such as flowering plants. So, can we humans learn anything from insect societies? In this talk I will attempt to answer this question in the affirmative, but with caution. I will consider such relatively non- controversial topics as communication, agriculture and robotics but also some relatively controversial topics such as cooperation, conflict, collective decision making and democracy.

Speaker Bio: 
Raghavendra Gadagkar, Ph.D. (Indian Institute of Science, Bangalore, 1979), studies Animal Behaviour, Ecology and Evolution and is especially interested in the origin and evolution of social life in animals. Gadagkar is now DST Year of Science Chair Professor at the Centre for Ecological Sciences, Indian Institute of Science and Non-Resident Permanent Fellow of the Wissenschaftskolleg zu Berlin. He has published over 350 research papers, articles and three books, Survival Strategies (Harvard University Press, 1997), The Social Biology of Ropalidia (Harvard University Press, 2001) and How to Design Experiments in Animal Behaviour (Open-access e-book, Indian Academy of Sciences, 2021). He has been recognized by several awards including the Shanthi Swarup Bhatnagar Prize, the Third World Academy of Sciences award in Biology and the Cross of the Order of Merit of the Federal Republic of Germany. He is a fellow of the Indian Academy of Sciences, the Indian National Science Academy, the National Academy of Sciences, India, The World Academy of Sciences, Leopoldina, The German National Science Academy, International Member, National Academy of sciences, USA and Foreign Honorary Member, American Academy of Arts and Sciences. He has served as a member of several committees including the Scientific Advisory Committee to the Cabinet, Government of India.

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