Does predation drive synchrony in prey dynamics or does prey asynchrony drive predator dynamics? A test using small mammal prey and vertebrate predators in Britain and Ireland.

Predation is a potent force that can synchronise prey populations as predators shift their attention to more dense, hence, profitable prey. Predation is most potent in fluctuating populations (Vasseur & Fox, 2009). Asynchronous populations of the same prey species may functionally have the same stabilizing influence on predator-prey interactions as populations of different species that are not synchronised with each other.

What is unknown is why some in some instances predators synchronise their prey through depletion (to the point of experiencing starvation and a wide amplitude numerical response), while in other ecosystems, similar guilds of predator species preying on similar prey assemblages fail to synchronise prey populations, whether of the same or alternate species.

This project will exploit two outstanding and complementary opportunities to resolve uncertainty on how birds of prey, stoats and weasels shape prey population synchrony, and how prey asynchrony fuels variation in predator reproduction and survival. The student will exploit existing and new data to further general understanding of predator prey interactions by considering how predator performance reflects both spatial and temporal variance and spatial gradients in prey availability.

In Kielder Forest, Great Britain, detailed, long-term studies of cyclical field voles and non-cyclical bank voles revealed changing patterns of spatial asynchrony including spatially organised travelling waves and cyclicity. The student will exploit and contribute to an unparalleled long-term study of ringed tawny owls using nest boxes and that rely heavily on small mammals as prey. Prey offtake estimates by different components of the populations will be related to spatial estimates of prey abundance. More limited data also exist on the breeding performance of barn owls and other vole predators in the same ecosystem. In Ireland, profound change in small mammal community composition, and hence prey availability, have taken place following recent invasion by non-native bank voles and greater white-toothed shrews in a hitherto simplified prey community dominated by wood mice and pygmy shrews. This has resulted in dramatic changes in species abundances and small mammal biomass likely destabilising predator-prey dynamics relative to multiple invasion fronts establishing a spatial wave in terms of impact. The student will quantify to what extent native and invasive prey are exploited by avian predators along steep gradients in prey availability.

QUADRAT is a NERC-funded Doctoral Training Partnership (DTP) between the University of Aberdeen and Queen’s University Belfast. Students will gain access to a year of training where field experience and academic excellence are the focus. Specific training will cover experimental and sampling design and analyses of population dynamics (spatial capture-recapture, occupancy modelling), and spatial patterns analysis, ecosystem networks with R. The student will benefit from the support of Forestry England acting as Case partner and contributing to awareness of management of forests for multiple uses including production and the promotion of biodiversity.

The successful candidate will be based at the School of Biological Sciences, University of Aberdeen and supervised by Xavier Lambin, Professor of Ecology and co-supervised by Dr Neil Reid, Senior Lecturer in Conservation Biology, Queen’s University Belfast.