QUADRAT DTP CASE: Rewilding and the return of interacting meso-predators: Understanding, modelling and monitoring predator-prey dynamics in non-equili

Predation is an influential trophic interaction in ecosystems that may limit or regulate the abundance of prey species. Predator-prey interactions involving specialist predators may be tight and reciprocal between pairs of species, sometimes leading to population cycles. Where generalist predators, which are adept at prey switching, are present, interactions may be more diffuse, involving a larger number of species. While ecological theory concerning predator-prey interactions is well developed, it generally does not account for spatial variation in the distribution of the alternative prey species that are available to generalists. Modelling of non-spatial approximations typically assumes random mixing of individuals and spatially uniform strength of interactions between predator and prey species.

However, prey species are often spatially heterogeneously distributed in real ecosystems, reflecting variation in the distribution of habitats and preferences, and for some cyclical populations, self-organised patterns such as travelling waves. Therefore, the scope for individual predators experiencing scarcity of their favoured prey to switch their attention to alternative prey is also heterogenous in space. Furthermore, intraguild predation, where one species kills and consumes another is commonplace.

The aims of this studentship are
i) to advance understanding of how spatial variation in the abundance of interacting predators and their prey switching response creates spatial heterogeneity in predation pressure and prey performance
ii) to determine under what circumstances endangered prey may benefit from partial refuges from predation, an issue with multiple applications to conservation.

Long term ecosystem studies, much existing data and the spread of pine martens in Kielder Forest create an opportunity to understand how the impacts of multiple predators may be additive, or whether interactions between predators, such as facilitations or intra-guild predation, may contribute to high spatial heterogeneity in predation pressure. Here, tawny owl demography reflects variation in the abundance of field voles. Tawny owls fall prey to goshawks and pine martens. Martens scavenge goshawk kills. Martens and foxes also rely on field voles in years of peak abundance.

Research objectives are broadly
- To characterise spatial patterns in abundance and demographic variation in selected prey, meso- and top predator species, and how these patterns relate to the abundance of predators.
- To characterise spatial patterns in predation pressure experienced by prey and mesopredator species with potentially strong interactions with higher trophic levels using e.g. camera traps, capture recapture, occupancy modelling.
- To characterise the processes, including prey switching, intra- and interspecific interactions amongst predators and selectivity of predation towards some age classes, that may contribute to the above patterns.
- To synthesise empirical information in spatially explicit models of this subset of the vertebrate community to generate predictions on the way ecosystems may change while experiencing trophic rewilding.

This CASE studentship is a partnership with Forestry England providing opportunities to gain experience in multi-use land management. Applicants will be enthused by population and community ecology, eager to collect field data during ~6 months/year, have an aptitude and eagerness to gain training with statistical analysis and be keen to work with practitioners. A driving licence is essential.