My current research interests lie in the causes and consequences of individual variation in growth in cooperative societies. Growth is one of the most important life-history traits: it reflects the tradeoff between age and size at maturity; and rapid growth in early life can have long-term consequences into adulthood. However, measures of growth in the wild are difficult to attain and formal investigations of growth in cooperative societies have only recently received attention. I am currently quantifying the relationship between size and age in meerkats, so that parameters of standard non-linear growth equations (e.g. asymptote and growth rate function) can inform future analyses. I aim to investigate whether female meerkats, for which body size is an important predictor of fitness, attempt to outgrow their sisters to maximise their chances of becoming dominant. Finally, I will be investigating the relative influence of social and ecological conditions experienced in early life on long-term growth trajectories.

Individual variation in helping behaviour in meerkats 

In cooperatively breeding species, variation in contributions to cooperation can often be explained by differences in sex, age or relatedness. However, there is often striking individual variation in helping effort that cannot be explained by these factors. For my PhD research, I investigated individual variation in helping in cooperatively breeding meerkats. Specifically, I approached variation in helping from three different perspectives: first, how early conditions influence later helping behaviour; second, the extent to which individuals are consistent in their helping over time and across contexts; and finally, the relationship between helper-offspring communication and variaton in cooperative behaviour.  

Previous Research
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In 2004, I was awarded a Royal Society Summer Studentship with Mike Cant investigating aggression and reproductive suppression in primitively eusocial paper wasps (Polistes dominulus). During my MSc in Biology at Oxford (2004-2005), I conducted research projects with Angus Buckling on the coevolution between bacteria and bacteriophage; and with Ben Sheldon and Clare Andrews on sex differences in begging vocalisations of blue tit nestlings.

Publications
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8.) S. English, Nakagawa, S. & Clutton-Brock, T. H. (2010). Consistent individual differences in cooperative behaviour in meerkats (Suricata suricatta). Journal of Evolutionary Biology 23(8): 1597-1604.

7.) Madden, J.R., H.P. Kunc, S. English and T.H. Clutton-Brock (2009) Why do meerkat pups stop begging? Animal Behaviour 78:85–89.

6.) Madden, J.R., H.P. Kunc, S. English, M.B. Manser and T.H. Clutton-Brock (2009) Do meerkat (Suricata suricatta) pups exhibit strategic begging behaviour and so exploit adults that feed at
relatively high rates? Behavioural Ecology & Sociobiology 63(9):1259-1268.

5.) Madden, J.R., H.P. Kunc, S. English, T.H. Clutton-Brock and M.B. Manser (2009) Calling in the gap: competition or cooperation in littermates’ begging behaviour? Proceedings of the Royal Society (B) 276(1660): 1255-1262.

4.) Manser, M.B., H.P. Kunc, J.R. Madden, S. English and T.H. Clutton-Brock (2008) Signals of need in a cooperatively breeding mammal with mobile offspring. Animal Behaviour 76(6): 1805-1813.

3.) S. English, H.P. Kunc, J.R. Madden and T.H. Clutton-Brock (2008) Sex differences in responsiveness to begging in a cooperative mammal. Biology Letters. 4(4): 334-338 [PDF]

2.) M. A. Cant and S. English (2006) Stable group size in cooperative breeders: the role of inheritance and reproductive skew. Behavioral Ecology 17(4):560-568. [PDF]

1.) M. A. Cant, S. English, H. K. Reeve, J. Field (2006) Escalated conflict in a social hierarchy. Proceedings of the Royal Society B, 273, 2977-2984. [PDF]