Paws without claws? Effects of carnivore comeback in European anthropogenic landscapes

In most European countries there are now permanent, reproducing populations of wolves, lynx and/or brown bears. In some countries, all three. But it is not virgin land that these animals recolonize, but rather lands that are characterized by high human activity.

In a review article in the Proceedings of the Royal Society B a European research group highlights gaps in knowledge on the effects of carnivores in human-dominated landscapes.

"There is a widespread perception that the return of large predators will save biodiversity," says Joris Cromsigt, Swedish University of Agricultural Sciences (SLU), who is one of the authors.

This view is partly based on experiences from Yellowstone National Park. When wolves were reintroduced in this national park, grazing pressure was reduced on the vegetation along the watercourses, which in turn led to a richer flora and fauna.

"However, in Europe predators are now returning to landscapes that are strongly modified by humans. Man is part of these ecosystems. Although we are not always physically present, these landscapes are still heavily shaped by us," for example, through forestry and hunting.

The ecological impact of large carnivores will most likely be quite different in these anthropogenic landscapes. The review that the authors put together suggests that several of these human actions may mitigate the top-down effects of large carnivores. In other words, humans may remove the claws from the carnivores' paws. Perhaps even more important is that the authors suggest that most of the research done so far on the role that predators play in ecosystems has been carried out in landscapes with very low human impact.

"Human activity must be included in research on the ecological effects of large carnivores. This article emphasizes that there are many unexpected ways how humans affect the role of large carnivores in ecosystems," says Cromsigt.