James Higham, New York University, Anthropology
Location: University of Exeter, Streatham Campus, Exeter EX4 4QJ
This project is one of a number that are in competition for funding from the NERC Great Western Four+ Doctoral Training Partnership (GW4+ DTP). The GW4+ DTP consists of the Great Western Four alliance of the University of Bath, University of Bristol, Cardiff University and the University of Exeter plus five Research Organisation partners: British Antarctic Survey, British Geological Survey, Centre for Ecology and Hydrology, the Natural History Museum and Plymouth Marine Laboratory. The partnership aims to provide a broad training in earth and environmental sciences, designed to train tomorrow’s leaders in earth and environmental science.
For further details about the programme please see http://nercgw4plus.ac.uk/
Individuals who are well integrated into society have greater access to resources and tend to live longer [2-4]. Why some individuals are socially isolated is therefore puzzling from an evolutionary perspective. Studies of humans and other group-living animals have documented individuals that are very socially isolated compared to other members of their population [1, 5, 6]. Isolated individuals may be pushed to the periphery of their social networks by extrinsic factors, such as competitive exclusion.
However, social isolation could also be a viable alternative evolutionary strategy whose benefits arise in certain contexts, such as during spikes in within-group competition levels, or in association with particular life-stages. These contexts may be common or severe enough to drive selection but not common enough to be detected by most studies, which tend to be relatively short-term and focused on relatively well integrated individuals. This project aims to test hypotheses on the potential benefits of social isolation, and to answer outstanding questions regarding the evolution and persistence of isolated individuals.
Project Aims and Methods
This project will combine theoretical models with field-based empirical data on the health, longevity, reproductive output, and social behaviours of a naturalistic population of rhesus macaque monkeys (Macaca mulatta). Leveraging the lead and co-supervisor’s established collaboration at one of the longest running field sites in the world, the Cayo Santiago field station in Puerto Rico , this project has three broad aims:
1. To use theoretical models to predict the contexts in which the benefits of social isolation outweigh the costs;
2. To use behavioural observations to establish whether socially isolated macaques attempt to integrate in social networks but are competitively excluded by others, or whether they fail to initiate social contact;
3. To test theoretical predictions in the Cayo Santiago macaques by comparing the biological success of isolated versus integrated individuals. This aim will be achieved using: a) long-term data on individual survival and reproductive success and; b) newly generated data on the health status of individuals, including immune activation and endocrine function.
The supervisors encourage student involvement in refinement of project design and research direction.
The student will have the opportunity to learn social network analysis and classic field-based behavioural ecology techniques for documenting behavioural variation, along with theoretical modelling and laboratory-based analyses of immune and endocrine biomarkers. The student will gain experience working abroad, with field-work based in Puerto Rico, and laboratory analyses conducted in the co-supervisor’s laboratory in New York.
References:  Brent LJN, et. al. (2017) Persistent social isolation reflects identity and social context but not maternal effects or early environment. Scientific Reports, 7.1: 17791.  Brent LJN, et. al. (2017) Family network size and survival across the lifespan of female macaques. Proceedings of the Royal Society B: Biological Sciences, 284.  Silk, J. B, et al. (2003). Social Bonds of Female Baboons Enhance Infant Survival. Science, 302: 1231-1234.  Brent LJN (2015). Friends of friends: are indirect connections in social networks important to animal behaviour? Animal Behaviour, 103: 211-222.  Fowler JH, et al. (2009). Model of genetic variation in human social networks. Proc. Natl. Acad. Sci., 106, 1720-1724.  Page, AE, et al. (2017) Hunter-gatherer social networks and reproductive success. Scientific Reports, 7, 1153.  Clutton-Brock, T. (2016). Mammal Societies. John Wiley & Sons.