Introducing grey wolves to Scotland to help control the red deer population. Source: Dr. Christopher Sandom/University of SussexDue to high numbers of red deer, the Scottish Highlands have an overgrazing problem and the solution may be a large predator and a fence. Research in the form of computer simulations shows that reintroducing grey wolves within a large, fenced reserve would provide a relatively effective and safe, for humans and livestock, means of lowering the red deer population.

The red deer are negatively impacting the ecosystem of the Scottish Highlands by preventing tree regeneration and ecosystem restoration. The key to lessening that impact could be allowing for the right level of wolf population growth to sufficiently reduce but not threaten the red deer numbers. Containment would help avoid unintended encounters between the predators and humans in the surrounding areas.

The research, led by the University of Sussex and the University of Kent, shows that a fence would limit encounters with people while allowing for the number of wolves required (as many as 80 wolves per 1,000 km²) to control the high red deer densities (up to 40 deer/km²). A barrier capable of retaining 75 percent of the wolves in the reserve would be optimum, according to the team’s analyses, which included reviewing a number of real-world examples that show the difficulty young wolves have when leaving a protected area to establish a new territory.

“Reintroducing the wolf has long been suggested as part of the solution to large red deer populations but there will always be concerns about how wolves interact with people in any rewilding project like this. This research shows that they could actually have an extremely beneficial impact in terms of making the rewilding process more effective,” said Dr. Christopher Sandom, lecturer in biology at the University of Sussex.

The researchers acknowledge that while fences are ideally avoided in biodiversity conservation, they can work well in situations where compromise is necessary. In this case, Dr. Sandom said, “A fenced reserve in Scotland could be a fantastic opportunity to return large predators to Britain, ecologically restore a large part of the Scottish Highlands and promote tourism.”

The return of the wolves, which were originally native to the area, would not significantly contribute to global wolf conservation, according to Dr. Joseph Bull, lecturer in conservation science at the University of Kent. The next step is to take what they’ve learned in the simulations and “test the ideas in practice -- by creating a reserve, reintroducing wolves and closely monitoring the system.”

Scientists from Aarhus and the University of Oxford (WildCRU) also participated in the research. The results are published at Restoration Ecology.