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.2017.0014, PDF
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.