Video: Marching giant crabs

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New paper: Friendship across species borders: factors that facilitate and constrain heterospecific sociality

Check out this new paper by Hari Sridhar, an INSA postdoctoral fellow in our lab.

Hari Sridhar and Vishwesha Guttal, 2018, Friendship across species borders: factors that facilitate and constrain heterospecific sociality, Phil. Trans. Royal Society of London B, 373: 20170014. http://dx.doi.org/10.1098/rstb.2017.0014PDF

Hari did some fabulous work on mixed-species flocks during his Ph.D. thesis, advised by my colleague Kartik Shanker. Hari continues that trend with another piece of fundamental contribution to the field. I am quite lucky to have been involved with him on this and had lots of new things to learn from him on the topic. The main proposal of the paper is nicely captured in the abstract:

Our understanding of animal sociality is based almost entirely on single-species sociality. Heterospecific sociality, although documented in numerous taxa and contexts, remains at the margins of sociality research and is rarely investigated in conjunction with single-species sociality. This could be because heterospecific and single-species sociality are thought to be based on fundamentally different mechanisms. However, our literature survey shows that heterospecific sociality based on mechanisms similar to single-species sociality is reported from many taxa, contexts and for various benefits. Therefore, we propose a conceptual framework to understand conspecific versus heterospecific social partner choice. Previous attempts, which are all in the context of social information, model partner choice as a trade-off between information benefit and competition cost, along a single phenotypic distance axis. Our framework of partner choice considers both direct grouping benefits and information benefits, allows heterospecific and conspecific partners to differ in degree and qualitatively, and uses a multi-dimensional trait space analysis of costs (competition and activity matching) and benefits (relevance of partner and quality of partner). We conclude that social partner choice is best-viewed as a continuum: some social benefits are obtainable only from conspecifics, some only from dissimilar heterospecifics, while many are potentially obtainable from conspecifics and heterospecifics.

This is published as part of theme issue on “Collective movement ecology” – a must read for everyone interested in movement ecology.

 

We have been awarded an UGC-UKIERI grant for collaboration with Colin Torney

We are delighted that we have been awarded an UGC-UKIERI grant for collaboration with Colin Torney in the School of Mathematics and Statistics, University of Glasgow and my colleague Dr Kavita Isvaran at CES. The grant amount is around 25,000 UK Pounds (equivalent to around 25 lakhs) and is valid from March 2018 – March 2020.

The ideas and work proposed here are by PhD student Akanksha Rathore who is jointly advised by me and Kavita. The grant will help both of our groups to travel back and forth, and work on investigating collective behaviour of blackbuck in the wild.

This is our second collaborative grant with Colin Torney, the previous one being funded by Royal Society which was instrumental in starting our collaboration as well as getting this grant.

 

 

 

New paper: Jaideep Joshi’s paper on mobility and cooperation

We have a bunch of papers from the lab that I haven’t time to announce on the website (but I do active tweet about them!). Here, I briefly post about the first thesis chapter of Jaideep Joshi is now published in Plos Computational Biology. It’s a really cool theory paper on mobility can actually promote cooperation.

Active-Passive-CollBeh-Simulations

(The above picture is from Figure 1 of the manuscript Joshi et al 2017, Mobility can promote the evolution of cooperation via emergent self-assortment dynamics, PLoS Computational Biology, 13(9): e1005732).

The way we set up the problem is that can we have cooperation in mobile organisms if we exclude well known mechanisms that facilitate the evolution of cooperation. Yes, indeed, we can find cooperation via emergent assortment of cooperators. This paper shows this counter-intuitive using heavy simulations of active or self-propelled particles, simulations of passive particles in turbulent media, and an analytical theory. All of it packed into a single paper.

Here is a nice summary of this work written by Ananya from Research Matters, a popular science communication webpage:

Classically, it has been argued that cooperative interactions evolve mostly among genetic relatives or individuals in close-knit environments – like the lions or the buffaloes. There is also the factor that these animals are mobile and often split and merge depending on the availability of food. What, then, could be the motivation for cooperative interactions to emerge among such dynamic groups that are not genetically related?

“Much of the earlier research on cooperation thought that mobility was a hindrance to the evolution of cooperation. This is because mobility allows defectors to invade and destroy clusters of co-operators, which are necessary for cooperation to sustain”, says Mr. Joshi. In their study, published in the journal PLOS Computational Biology, the researchers have considered two scenarios for mobility – one, where the individuals move through self-propulsion such as fishes and birds, and second, where the individuals move due to the flow of the medium they live in such as microbes.

The study demonstrates that, rather than hinder it, mobility can help animals evolve cooperation to form groups even among unknown individuals without any kinship. “Our study is like a thought-experiment, but aided by sophisticated theoretical and computational tools. However, our model can easily be adapted to real systems by incorporating features specific to those systems. These could include cancer cells, quorum sensing bacteria, mixed species bird flocks, or even grouping mammals such as spotted deer, baboons and elephants”, signs off Dr. Joshi.

Collective behaviour meeting in Germany

I am just returning from an highly stimulating workshop/conference on “Multi scale analysis and modeling of collective migration in biological systems”, Bielefeld, Germany, Oct 2017. 

One day of the conference was on collective behaviour in organismal biology. There were great talks on quantifying interactions in fish and sheep, intermittent behaviour in sheep, collective feeding in C elegans, models of swarming bees, criticality in schooling systems, etc. I gave a talk on our recent (unpublished) work on fish schooling by Amith-Kumar and Jitesh Jhawar followed by my previous work on evolutionary models of collective migration, including Jaideep’s recent work on cooperation.

It was great to catch up with Pawel Romanczuk (with whom I collaborated on locust cannibalism) and Guy Theraulaz (a leader in the field of collective behaviour). There were not too many people I knew previously. So it was nice to many others whose papers I had read but not never met.

Guy shared his fond memories of his visit to Bengaluru in 1990 when he attended International meeting on social insects. Guy has been encouraging me to organise a meeting on collective behaviour in Bangalore.  Should I 🙂 ?

Several of our lab members attend international conferences and workshops this summer

As I mentioned in the previous post, our postdoc is attending Ecological Society of America Annual Meeting in Portland this week. In addition, our lab had presence in various other international conferences and workshops this summer.

Four PhD students from our lab presented their work at the conference “Mathematical models in ecology and evolution” (MMEE) held at London in July 2017.

  1. Jaideep Joshi, final year student who has already submitted his thesis, presented his work on “Demographic noise and the evolution of tag-based cooperation”.
  2. Sumithra Sankaran, finishing her 4th year of PhD, presented her work on “Demographic noise promotes bistability in ecosystems”
  3. Jitesh Jhawar, finishing his 3rd year of PhD, presented his work on “Role of stochasticity in the dynamics of fish schools”
  4. Aakanksha Rathore, finishing her 2nd year of PhD, presented her work on “Spatial dynamics of Blackbuck herds”

Three of the students, Sumithra, Jitesh and Aakanksha, also attended BES organised one day symposium on movement ecology in London.

After the conference, Aakanksha went to visit Dr Colin Torney at University of Glasgow.

Jaideep went on to Puerto Rico to attend a workshop on tropical forest ecology.

Student trips were supported by funds from Indian Institute of Science (MHRD) and a grant from Royal society to visit Dr Torney’s lab.