Dr. Patricia Brekke
Research Fellow/Deputy EME theme leader
2011-Present: AXA-funded Fellowship, Institute of Zoology.
2009-2011: Leverhulme-funded Post-doctoral Research Assistant, Institute of Zoology.
2005-2009: NERC PhD student, Dept. Life Sciences, Imperial College London.
2002-2004: Research Assistant (Prof. Tim Birkhead), Dept. Animal and Plant sciences, University of Sheffield.
1999-2002: BSc. Zoology, University of Sheffield.
My research interests focus on the ecology, evolution and conservation of reintroduced species, particularly, the evolutionary and genetic consequences of reintroduction of wild bird populations. I routinely use pedigrees (quantitative genetics) and molecular tools to understand the role of inbreeding, genetic diversity loss and a species’ life-history traits on their vulnerability to extinction.
Genetic consequences of reintroduction:
Up to 90% of avian extinctions have occurred on islands and many surviving island bird species are reduced to small and isolated populations that remain at risk of extinction from stochastic processes. Conservation efforts for island species often use the reintroduction of a few individuals to initiate new populations, thus creating both founding and sequential bottleneck events. My research involves using establishment history and developing detailed genetic and pedigree data from the remnant and reintroduced populations of New Zealand endemic bird the hihi (Notiomystis cincta) to understand the patterns of genetic diversity loss and effects of inbreeding to inform conservation management.
Reintroduction founding events not only have profound genetic effects, but also evolutionary consequences as the newly founded populations are exposed to a new set of selection pressures. This process can lead to phenotypic, behavioural and genetic divergence between populations. I am interested in how reintroduction alters these life-history traits, in particular sexually selected ones and how species adapt to rapid environmental change.Micro-evolutionary consequences of reintroduction:
Historical population structure:
Small populations of island species face a number of genetic threats, but many are relative to their ancestral genetic state. Understanding historical patterns of genetic diversity, range size and structure of these populations can inform current and future conservation efforts on fundamental aspects of the species recovery. I apply molecular tools to historical museum specimens to resolve issues of taxonomic status, detect past levels and changes in genetic diversity and relate these to the modern remnant population structure and diversity. This information has important implications for current conservation and management of modern populations.
1. Brekke, P., Cassey, P., Ariani, C., Ewen, J.G. (2013) Evolution of extreme-mating behaviour: patterns of extra-pair paternity in a species with forced extra-pair copulation. Behavioural Ecology and Sociobiology.DOI:10.1007/s00265-013-1522-9
2. Walker L.K., Armstrong, D.P, Brekke, P., Chauvenet, A.L.M., Kilner, R.M., Ewen, J.G. (2013) Giving hihi a helping hand: assessment of alternative rearing diets in food supplemented populations of an endangered bird. Animal Conservation. DOI: 10.1111/acv.12026
3. Thorogood, R., Armstrong, D.P., Low, M., Brekke, P., Walker, L., Ewen, J.G. (in press) 1995 – present: A 15 year history of ecological research on Tiritiri Matangi Island’s Hihi. NZ J Ecol.
4. Brekke, P., Wang, J., Bennett, P.M., Cassey, P., Dawson, D.A., Horsburgh, G.J., Ewen, J.G. (2012) Post-copulatory mechanisms of inbreeding avoidance in the island endemic hihi (Notiomystis cincta). Behavioural Ecology. 23 (2): 278-284.
5. Brekke, P., Bennett, P., Santure, A., & Ewen, J. G. (2011) High genetic diversity in the remnant island population of hihi and the genetic consequences of re-introduction Mol. Ecol. 20: 29-45.
6. Brekke, P., Bennett, P. M., Wang, J., Pettorelli, N., Ewen, J. G. (2010) Male-biased inbreeding depression in an endangered bird. Proc. R. Soc. Lond. B. 277: 3677-3684.
7. Wang, J., Brekke, P., Huchard, E., Knapp, L. A., Cowlishaw, G. (2010) Estimation of parameters of inbreeding and genetic drift in populations with overlapping generations. Evolution.64: 1704-1718
8. Ewen, J.G., Thorogood, R., Brekke, P., Cassey, P., Karadasd, F. & Armstrong, D.P. (2009) Maternally invested carotenoids compensate costly ectoparasitism in the hihi. Proc. Natl. Acad. Sci. USA 106:12798-12802
9. Brekke, P., Dawson, D.A., Horsburgh, G.J. & Ewen, J.G. (2009) Characterization of microsatellite loci in the hihi, Notiomystis cincta (Notiomystidae, Aves). Molecular Ecology Resources 4: 1255-1258.
10. Birkhead, T.R., Pellatt, E.J., Brekke, P., Yates, R. & Castillo-Juarez, H. (2005) Genetic effects on sperm design in the zebra finch. Nature. 434: 383-387. _