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Causes and consequences of personality in the Seychelles warbler

Dr Hannah Dugdale (SoB), Prof Keith Hamer (SoB), Prof Terry Burke (U Sheffield), Prof David Richardson (U East Anglia), Prof Jan Komdeur (U Groningen, NL)

Project partner(s): Nature Seychelles (CASE)

Contact email:

‘Personality’ describes consistent behavioural differences between individuals. For example, some individuals may explore novel environments consistently more than others, resulting in different personalities along an exploration–avoidance axis. Exploration tendency may then be correlated with behaviour in a different context. Why such personality differences exist is intriguing – if individuals were more flexible in their behaviour, individuals could adapt their behaviour to variable natural environments. This PhD will investigate whether different personalities are associated with different life-history strategies, what their fitness consequences are, and the genetic basis of personality using genomic markers in a natural population (Fig.1).

In cooperatively breeding societies, individuals help to raise offspring that are not their own. Why individuals do this is a fascinating question. Individuals may remain in their natal territory and help to raise offspring that are not their own, they may stay and not help, or they may disperse to find a breeding position of their own. These different life-history strategies may be expected to favour a range of personalities, making cooperative breeding systems ideal for investigating the evolution of personality.

Figure 1: A Seychelles warbler (Acrocephalus sechellensis; Left, ©Hannah Dugdale) on the study site of Cousin Island, Seychelles (Right, ©Dave Richardson). Individual Seychelles warblers on Cousin are given a unique metal ring on their right leg, with a colour ring on top of it and two colour rings on the left leg that allows individual identification over their lifetimes. 

Theoretically, personalities may evolve if they are linked to an individual’s state. For example, risk-avoiding individuals should have higher future fitness expectations than riskier explorative individuals. Additionally, personalities could evolve if they are linked to frequency dependent fitness benefits. Accurate fitness measures, such as survival and reproduction, are fundamental to this question but they can be very difficult to measure in natural populations, as individuals may disperse from open study areas. Closed populations offer a solution to this, which when the subject of long-term studies that generate lifetime data over multiple generations offer a unique opportunity to study the evolution of personality.

For personalities to evolve, they must have a fitness benefit and a genetic basis. While studies of individual differences in behaviour in natural populations have shown that they can be repeatable and heritable, little is known about their underlying genetic architecture. Candidate genes have been identified but they tend to explain a small amount of genetic variation and these effects can even differ across populations. A genomic approach is therefore required to investigate the genetic architecture of personalities.

The student will use the exceptional model system of the Seychelles warbler (Fig.1). Seychelles warblers are a cooperatively breeding bird that show repeatable and heritable variation in personality (Fig.2), and are studied on an isolated island where fitness can be measured accurately. The student will have access to the exceptional long-term dataset and genetic pedigree, gaining skills in fieldwork, genomics, quantitative genetics and statistics. For example, the genetic pedigree will be used to study the fitness consequences and life-history trade-offs associated with personality. Next-generation sequencing will be used to investigate genomic regions associated with personality. Bioinformatics and statistical skills are an advantage, but training will be provided. The student will benefit from interactions with members of Seychelles Warbler Project ( and a vibrant academic environment at the University of Leeds, including support from LeedsOmics (

Figure 2: Measuring exploration of a novel environment in the field. The tent (left) contains three artificial trees (right) and exploration is measured as the number of hops, flights and total number of tress visited over five minutes.

The successful student will work with researchers at the Universities of Leeds, Sheffield, East Anglia and Groningen to investigate the causes and consequences of personality in a natural population. The student will address the following fundamental questions in evolutionary biology:

  1. Does personality predict dispersal and helping behaviour?
  2. What are the fitness consequences of personality – do risk-adverse individuals have higher early-life reproductive success than risk takers?
  3. Which genomic regions explain variation in personality?


You must hold an Honours (2.1 or higher) or Masters degree in a related subject such as Biology, Evolution, Genetics, or Zoology.

We are looking for a motivated student who has a keen interest in behavioural ecology and life-history evolution. Previous experience of bird ringing/observation, fieldwork in harsh environments, Access databases, bioinformatics and statistics would be beneficial; however, the student will receive excellent training in all of these skills. You will be required to conduct fieldwork on the long-term Seychelles warbler project, for a minimum of three seasons (up to 3 months per season).


You will be based within the Ecology and Evolution group, in the School of Biology at the University of Leeds, which was The Times and The Sunday Times University of the Year 2017. You will join Dr Hannah Dugdale’s research group and benefit from co-supervision by Prof Keith Hamer. Co-supervision will also be provided by Prof Terry Burke (University of Sheffield), and you will be part of the international Seychelles warbler project, which is run in conjunction with Prof David Richardson (University of East Anglia), Prof Jan Komdeur (University of Groningen), and Nature Seychelles. You will benefit from a wide-range of training courses offered by the School of Biology and the Leeds York NERC Doctoral Training Partnership. In particular, this PhD project will provide specialist training in:

  • Fieldwork, on the long-term Seychelles warbler project
  • Data management, of large datasets stored in an Access database
  • Statistical analyses, such as generalized linear mixed models applied in a Bayesian framework.
  • Bioinformatics, through the analysis of next-generation sequencing data.

Suggested reading

Edwards HA, Burke T & Dugdale HL. 2017. Repeatable and heritable behavioural variation in a wild cooperative breeder. Behavioral Ecology, 28(3):686–676

Edwards HA, Dugdale HL, Richardson DS, Komdeur J & Burke T. 2016. Exploration is dependent on reproductive state, not social state, in a cooperatively breeding bird. Behavioral Ecology, 27(6):1889-1896.

Edwards HA, Hajduck GK, Durieux G, Burke T & Dugdale HL. 2015. No association between personality and candidate gene polymorphisms in a wild bird population. PLoS ONE, 10(10): e0138439.

Edwards HA, Winney IS, Schroeder J & Dugdale HL. 2013. Do rapid assays predict repeatability in labile (behavioural) traits? A reply to Biro. Animal Behaviour, 85(3): e1–e3.

Patrick SC, Chapman JR, Dugdale HL, Quinn JL & Sheldon BC. 2012. Promiscuity, paternity and personality in the great tit. Proceedings of the Royal Society, B  279(1734): 1724–1730 

Related undergraduate subjects:

  • Bioinformatics
  • Biology
  • Ecology
  • Evolution
  • Molecular ecology
  • Natural sciences
  • Zoology