Speaker
Description
Massei, Giovanna1*; Gordon, Iain J.2-5; Wimpenny, Claire6; Manning, Adrian D.2
1 Botstiber Institute for Wildlife Fertility Control, Department of Environment & Geography, University of York, York, UK
2 The Australian National University, Fenner School of Environment and Society, Acton, Australia
3 The James Hutton Institute, Dundee, UK
4 Central Queensland University, Townsville, Australia
5 James Cook University, College of Science and Engineering, Townsville, Australia
6 Office of Nature Conservation, ACT Government, Dickson, Australia
* GMassei@botstiber.org
DOI: 10.20315/evmc.2025.045
Rewilding is becoming a mainstream approach to ecosystem restoration. Most rewilding projects include populations of large free-roaming herbivores that can grow fast. As this growth can undermine long-term rewilding goals, there is a pressing need to consider if, when, and how to intervene in the management of large herbivore populations during the rewilding process. In parallel, there is growing demand for non-lethal population management options. We will examine how “no intervention” as well as four types of nature-mimicking interventions could be applied to rewilding processes. ‘No intervention’ influences some of the natural processes that govern herbivore population size and distribution. Where top-down processes are absent, bottom-up processes will eventually predominate and often result in starvation and ultimately death. This impacts animal welfare, public trust and risks ecosystem degradation. Culling mimics the effects of emigration, predation, and disease and affects animal behaviour. Interventions that mimic the presence of predators can be used to create landscapes of fear: anti-predator behaviour can affect ecosystem structure, composition, function, and restoration. Translocation can have the same effect of culling and fertility control but also increased risk of disease transmission, and significant welfare costs. Fertility control is achieved via surgical sterilisation, hormonal implants, and injectable contraceptive vaccines. Fertility control mimics the outcome from predation, disease, and density dependent effects that lower birth rate and can reduce costs, negative welfare issues, and increase public support for rewilding. No single intervention is likely to work alone, and regimes combining different interventions will be needed throughout the rewilding process. We will explore examples of these interventions to reduce environmental, economic, animal welfare, social and cultural impacts, and crucially contribute to maintaining local support for rewilding projects.
