Foraging in Ants

I have recently moved to Switzerland to join the fantastic group of Prof. Laurent Keller at the Department of Ecology and Evolution, University of Lausanne. I will be working on exploring foraging and other behaviours in ants using an amazing ant tracking system. Watch this space for more details soon!

Information Use in bumblebee foraging

As part of a Zukunftskolleg Invited Research Visit, my collaborators and I have recently started a project looking at the recruitment process in bumblebee foraging. We plan to explore how workers in the nest respond to changes inside and outside the colony and what factors influence their decision to forage.

This project is on hold, as the pandemic forced me to leave Germany before we could start experiments. But we'll be back with updates sometime in the future!

Collaborators: Dr. Anja Weidenmüller and Dr. Morgane Nouvian

Waggle dance behaviour in Asian honey bees

While in Bangalore, I have had the opportunity to work with all three of the honey bee species found in this corner of the world: Apis florea, A. cerana and A. dorsata. Compared to the western honey bee, A. mellifera, very little is known about the behaviour and ecology of the Asian honey bee species. In line with my broader interest in social communication and interactions, I have been a part of projects focused on the waggle dance communication in these species.

Check out details of the individual projects through the tabs below.

Dance Dialects Dance Follower Behaviour Optic Flow and Dance Behaviour

Dance Dialects

In a project spearheaded by Patrick Kohl from the University of Würzburg, we looked at whether honey bee populations show dance dialects (differences in the slope between the waggle dance duration and distance of the food source indicated). We found that the species show differences in the slope which are inversely correlated with their foraging range (with A. cerana having the steepest slope and the shortest foraging range, and A. dorsata the shallowest slope and the largest foraging range in Bangalore). Thus, dance dialects represent an adaptive evolution to the environmental food availability in honey bees.

The manuscript detailing these findings is published in the journal Proceedings of the Royal Society B.

Collaborators: Patrick Kohl, Neethu Thulasi, Benjamin Rutschmann, Dr. Ingolf-Steffan Dewenter and Dr. Axel Brockmann

Dance Follower Behaviour

Signals produced by the foragers in the waggle dance vary amongst the extant honey bee species (A. florea produces a visual but not an acoustic signal, A. cerana does the reverse while A. dorsata produces both). However, nothing is known about how the receivers of these signals, the dance followers, respond to these differences. We found that the dance follower behaviour is conserved across all three species throughout the waggle dance and is similar to follower behaviour in A. mellifera. This indicates that the mechanism by which spatial information is transmitted in the waggle dance is likely to be conserved across the genus Apis.

The manuscript detailing these findings is published in the journal Animal Behaviour.

Collaborators: Smruti Pimplikar, Neethu Thulasi and Dr. Axel Brockmann

Optic Flow and Waggle Dance

The effect of optic flow on the waggle dance behaviour has been previously explored in A. mellifera, using foragers trained in an artificial tunnel. My collaborators and I looked at the effect of natural variation in the optic flow of foraging environments on the waggle dance activity of A. florea and A. cerana. We found that, similar to A. mellifera, higher optic flow conditions led to a more rapid increase in the waggle phase duration with distance, but only in A. florea and not A. cerana.

The manuscript detailing these findings is published in the Journal of Experimental Biology.

Collaborators: Neethu Thulasi, Patrick Kohl, Sachin Suresh, Benjamin Rutschmann and Dr. Axel Brockmann

Individual variation in recruitment activity

During my PhD, I was primarily interested in the interplay between individual and social factors in regulating an individual honey bee forager’s decision to recruit to a food source using the waggle dance. Through some excellent collaborations, we found that the total recruitment activity of an individual is a combination of two behavioural parameters, dance probability and dance intensity, which are in turn affected differently by individual and social factors.

Check out details of the individual projects through the tabs below.

Social Modulation Mechanisms Agent-based Simulations

Social Modulation of Individual Differences

In this project, we were interested in looking at how recruitment activity to the same food source varies within a group of foragers. We found that foragers showed strong differences, consistent over days, in their probability of dancing and intensity of dances for the same food source. When we removed some foragers from the group, only the more active individuals changed their total recruitment activity and did so by increasing their probability of dancing and not the intensity. Since the removal of foragers potentially changes social interactions in the hive, the probability of dancing is associated more with the ‘social’ perception of the food reward, as compared to the dance intensity.

The manuscript detailing these findings is published in the journal Behavioral Ecology and Sociobiology.

This project was done under the guidance of Dr. Axel Brockmann

Mechanisms underlying Individual Differences

To explore potential mechanisms underlying inter-individual variation in recruitment activity within honey bees, we looked at sucrose response thresholds and whole-brain transcript levels of specific genes in individual foragers. The sucrose responsiveness is linked to the ‘behavioural state’ that an individual is in, and while dance intensity showed a small positive correlation with sucrose responsiveness, dance probability did not. We also found that the foraging gene showed a strong negative correlation with the total recruitment activity of individual foragers, adding a new dimension to the role this gene plays in food related motor behaviours in insects.

The manuscript detailing these findings is published in the journal Genes, Brain and Behavior.

Collaborators: Ann-Kathrin Bröger, Dr. Markus Thamm, Dr. Axel Brockmann and Dr. Ricarda Scheiner

Agent Based Model Simulations of Dance Behaviour

One exciting, but largely unexplored, area of research is the role that consistent individual variation plays within social insect groups. Building on an excellent agent-based model by Shürch and Grüter, we first introduced variation in the probability and intensity of dancing amongst the agents that captures the individual variation in total recruitment seen in our empirical data. We then compared the food influx of colonies with and without inter-agent variation to determine how this variation affects the colonies fitness under different environmental conditions.

The manuscript detailing these findings is currently available as a pre-print on bioRxiv.

Collaborators: Supraja Rajagopal and Dr. Axel Brockmann