| The motivation letter is also attached to the application as a PDF-file
Since Oscar och Lili Lamms Minn Fundation’s aim is to stress out the importance of research and nature conservation, my project merges into this frame by looking at population dynamics of a multi-species system in Grimsö Wildlife Research Area (GWRA).
PROJECT DESCRIPTION
Predator-prey interactions are a key component in ecology. Because of top-down and bottom-up effects, sympatric predator and prey populations influence the dynamics of each other, and sometimes affecting a wide range of species because of the trophic links involved, so called cascade effects. Beyond the natural frame, these processes can also disrupt social-ecological systems because of conflicts that may arise between large carnivores and people, hunters and animal husbandry.
In Sweden, roe deer (Capreolus capreolus) is an invaluable witness of large carnivores recovery that began during the last century. This small cervid is mainly preyed upon by foxes (Vulpes vulpes), lynxes (Lynx lynx) and wolves (Canis lupus), thereby reflecting the dynamics of the top-predators in this part of Scandinavia. The main question of my Maser Thesis is: to what extent does the recovery of large carnivores affect the roe deer population dynamics?
METHODS
To answer this question, I will in collaboration with my supervisor (Prof. Petter Kjellander), use a radio-telemetry time-series collected at GWRA of almost 40 years, based on 458 known-aged roe deer followed throughout their life. This population have experienced four “risk conditions”: one predator-free environment during the episode of sarcoptic mange (Sarcoptes scabiei) that paused fox predation for a few years, and three predator communities successively adding fox, lynx and finally during the last eight years also wolf predation risk.
To assess the importance of the “recovery-effect”, I will use the latest tools in terms of survival analysis. First, the Non-Parametric Cumulative Incidence Function Estimator that helps testing the hypothesis of additive vs. compensatory predation-related mortalities. Secondly, extending this competing-risk framework, I will investigate the influence of several variables (Sex, Age class, Snow condition, etc.) on each predation risk: Lunn & McNeil (1989) stratified method will be used and Cox Proportional Hazards implemented to detect the main drivers of prey selection.
Finally, a Matrix-Projection Model will be parameterized with the survival rates obtained from the regressions and the reproductive rates of the same population, in order to get the roe deer population growth rate within each predator community.
OBJECTIVES
In this way I will be able to detect a trend describing how the roe deer population evolves with an increasing number of predators.
The quality of the data is obviously unique and together with a thorough statistical analysis it will provide results with high precision and consequently high potential to publish in high ranked international peer-reviewed journals. Most importantly, it will contribute to the societal process towards a knowledge based wildlife management of a fauna also including large carnivores.
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