Cecile Agnes Edith Carpentier

• Carpentier, Cecile Agnes Edith; Heurich, Marco Dietmar; Devineau, Olivier; Gimenez, Olivier & Linnell, John D. C. (2026). Adaptive harvesting of two trophic levels stabilises predator–prey dynamics. Simulations with Eurasian lynx and European roe deer. Wildlife Biology. ISSN 0909-6396. doi: 10.1002/wlb3.01628. Full text in Research Archive Show summary

  Europe has seen the recovery of many species of wild herbivores, which are now widespread across much of the continent. In addition, large carnivores are also recolonising many European countries. Most ungulates are managed through hunting, but natural predation can also have a significant influence in many areas. Therefore, the management of large herbivores must increasingly account for both hunting pressure and the impact of predation. Recent studies suggest that lynx predation can have a significant impact on roe deer population dynamics, both by targeting reproductive individuals and by exerting consistently high predation pressure across a wide range of prey densities. Here, we develop a two‐species predator–prey matrix population model that integrates lynx and roe deer through functional and numerical responses. We test a set of management rules, applied to both prey and predators, to examine whether joint hunting of both species can prevent prey declines and stabilise the population dynamics. Our simulations show that protecting (i.e. not hunting) either species increases the predator population, which in turn leads to a decline in the prey population. Hunting only the prey worsens their fate due to the addition of hunting and predation. However, simultaneous hunting of predators and prey, adaptively regulated through simple heuristics, does help prevent prey declines. We also show that the initial densities of the predator and prey population have significant impact on the outcome of the simulations. The importance of relative predator and prey population densities highlights the need for adaptive harvesting that monitors and adjusts to current predator and prey population levels.

• Boyce, Mark S.; Carpentier, Cecile Agnes Edith & Linnell, John Durrus (2025). Coexisting with large carnivores based on the Volterra principle. Conservation Biology. ISSN 0888-8892. 39(4). doi: 10.1111/cobi.14448. Full text in Research Archive Show summary

  Coexistence with large carnivores represents one of the world’s highest profile conservation challenges. Ecologists have identified ecological benefits derived from large carnivores (and large herbivores), yet livestock depredation, perceived competition for shared game, risks to pets and humans, and social conflicts often lead to demands for reduction of predator numbers from a range of stakeholder groups. Nearly 100 years ago, Vito Volterra predicted that increased mortality on both prey and predators results in increased abundance of prey and decreased abundance of predators. This principle appears to be robust and often consistent with the objectives of wildlife management. Although seldom recognized, and rarely tested in the field, the Volterra principle is a fundamental outcome of ecological theory with important implications for conservation.

• Carpentier, Cecile Agnes Edith; Heurich, Marco Dietmar; Gimenez, Olivier; Devineau, Olivier & Linnell, John Durrus (2024). Cumulative mortality effects on roe deer population dynamics in the boreal forest: Searching for pathways of population persistence. Global Ecology and Conservation. 56. doi: 10.1016/j.gecco.2024.e03318. Full text in Research Archive Show summary

  Ungulate populations can exhibit various growth patterns, which are influenced by factors such as predation and resource availability. Favourable environments can lead to irruptive growth, resulting in resource depletion. However, additional pressures from predation, and hunting can potentially impact population development leading to declines or even local extinctions. This study uses simulation models to explore the potential impact of multiple mortality sources on roe deer populations. We develop an age-structured, two-sex demographic matrix model for roe deer, which we parameterise with empirical demographic estimates obtained from published studies in Norway. We develop scenarios to assess the influence of mortality sources such as hunting, predation by lynx and red foxes, and environmental stochasticity on roe deer population dynamics. When simulating favourable environments without predation, roe deer populations tended to erupt due to the species’ rapid reproductive capacity. However, additional sources of mortality, such as predation or harvest, lead to severe population declines, and even to quasiextinction, especially when occurring in combination. Environmental stochasticity such as periodic severe winters with heavy snowfall reduces the growth rate and population densities even further. On the other hand, accounting for some form of spatial heterogeneity through immigration and refuges stabilised populations, with a reduced risk of quasi-extinction. Our results provide meaningful insights into the properties of this system allow implications for the management and identify areas where further exploration is needed. Additive mortality Matrix model Population dynamics Predator-prey Roe deer (Capreolus capreolus) Wildlife management

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• Carpentier, Cecile Agnes Edith & Linnell, John Durrus (2025). Sustainable Harvest Strategies in a Lynx-Roe Deer Predator-Prey System: Insights from a Modelling Approach. Full text in Research Archive
• Carpentier, Cecile Agnes Edith; Linnell, John Durrus; Heurich, Marco Dietmar & Gimenez, Olivier (2026). Modelling prey dynamics in multi-predator systems: European roe deer (Capreolus capreolus) persistence under predation by Eurasian lynx (Lynx lynx) and hunting in northern landscapes. Universitet i Innlandet / University of Inland Norway. ISSN 9788283806342. Full text in Research Archive Show summary

  With the return of large carnivores to human-dominated landscapes, both humans and wild prey must adapt to this new environment, which brings increased predation pressure on prey and new conflicts between humans and carnivores. For wild ungulates, the combined effects of predation and human harvest can increase their vulnerability to population declines or even local extinction. This dissertation explores the drivers of roe deer persistence in a multi-predator Scandinavian system using complementary modelling approaches. The first two chapters investigate the effects of biotic and abiotic factors on roe deer populations, using two modelling approaches. Chapter I focuses on the cumulative effects of predation, hunting, and stochastic climatic events, while also exploring, in a relatively general and theoretical framework, the role of immigration and landscape refuges on roe deer population persistence using a matrix population model. This chapter emphasises the importance of additive mortality sources and highlights the existence of underlying mechanisms that enable the deer population to persist. Chapter II focuses in more detail on how spatial heterogeneity in mortality risk at the individual level influences population dynamics using a spatial individual-based model, highlighting the importance of refuges, movement, and spatial variation in risk in a multi-predator context. The final two chapters investigate the role of human harvest in predator-prey systems. Chapter III discusses the relevance of a century-old principle for modern wildlife management, particularly in mitigating human-carnivore conflicts. Chapter IV evaluates different harvest strategies in the lynx-roe deer system using a coupled predator-prey matrix model. The results show that even relatively simple heuristic strategies that adaptively harvest both predator and prey to changing population densities improve the stability and persistence of both populations compared to non-adaptive approaches. Combining complementary modelling approaches, this dissertation provides key insights into the mechanisms underlying predator-prey dynamics and highlights the importance of integrating predation, harvest, and spatial processes for the sustainable management of wildlife in human-dominated landscapes.

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