Almost 4 years after arriving in Aberdeen, I successfully defended my thesis on the 6th July, with only a few typos to correct. Dr Pierre Bize from the University of Aberdeen and Jean-Michel Gaillard from Claude Bernard University Lyon were my internal and external examiners and really put me through my paces, finding the limits of my knowledge and work in the friendliest way possible. Although I found it a real challenge I can honestly say that I really enjoyed my PhD and feel very lucky to have had the opportunity to work on such an amazing project and have had such a fantastic team of supervisors as Professor Xavier Lambin (University of Aberdeen), Dr Philip Whitfield (Natural Research Ltd), Dr Alex Millon (Mediterranean Institute of Marine and Terrestrial Biodiversity and Ecology), Dr Steve Petty (University of Aberdeen), Martin Davison (UK Forestry Commission) and Mick Marquiss (University of Aberdeen).
My thesis entitled The impact of increasing predation risk and declining food availability on the population dynamics of a long-lived mesopredator involved both using and contributing to a long-term multi-species (Northern goshawk, Tawny owl and Field voles) dataset in order to gain a better understanding of the role that environmental processes play in shaping animal population dynamics and demography. The top-down impact of predation and bottom-up influence of food availability are thought to be two of the most important environmental processes affecting population dynamics and demography of species occupying middle trophic levels. However, it is not clear whether the impact of one environmental factor on population dynamics and demographic rates is augmented or lessened by changes in other environmental factors or whether an individual’s characteristics affect the way in which they respond to changes in environmental conditions to have an impact at the population level. During my PhD I examined the extent to which both changes in predation pressure and food availability shape population dynamics (population size, recruitment and immigration) and demography (survival, reproduction, life-history trade-offs and reproductive strategies) in a long-lived species, the tawny owl, by taking advantage of a natural increase in predation risk (goshawk abundance) and a decline in food availability (field vole densities).
Shortly after submitting my thesis at the end of May I attended the IRSAE course “Structured decision making and adaptive management” course at Aarhus University. The course was really interesting, well-structured and also a lot of fun. I particularly liked working on our group’s capstone problem, which was focussed on how best to manage Norway’s wolf population. Although it was not directly relevant to my PhD, I am really glad I attended the course, because in a small way the better understanding of the issues surrounding wolf management and population ecology which I gained during the course actually helped me secure a 2-year postdoc at Michigan Tech University, where I will be working on the population biology of wolves and elk in Yellowstone national park and their predator-prey interactions. Therefore I am really grateful to have been part of the IRSAE network during my PhD and encourage other members to take advantage of the opportunities it offers. I guess all that is left to say is that I am really excited about starting the postdoc at the beginning of September, and will try to keep you updated about how I get on. If you want to know a bit more about the salient findings of my thesis, feel free to contact me directly at my new institution!
Sarah R. Hoy