News release

From: Springer Nature

A ‘human shield’ is helping jackals spread across Europe
Human activity may be enabling the expansion of golden jackals across Europe by reducing the suppressive effect of grey wolves, suggests research published in Nature Ecology & Evolution. This human-mediated interaction could allow jackals to occupy up to 75% of the continent, almost six times more than the current area, the authors suggest.

Previous research has suggested multiple reasons for the spread of jackals in Europe, such as climate warming, land cover change and the absence of predators. Wolves, which can outcompete and prey on jackals, were once widespread across the continent, but centuries of persecution and growing human populations have restricted them to a fraction of their former range. Research conducted in North America has shown that the human-driven absence of wolves is beneficial to coyotes, which are similar in size and ecology to golden jackals, but whether similar dynamics are ecologically important in Europe has remained unclear.

Nathan Ranc and colleagues analysed jackal howling survey data collected from 2001 to 2017 at 8,991 locations across 13 European countries. They found that shorter snow-cover duration, intermediate forest cover and proximity to water bodies are all associated with jackal presence. Wolf presence was found to be the strongest constraint on jackal occurrence: jackals are most likely to be present where wolves are absent and least likely in the core areas of stable wolf packs. However, proximity to human settlements appears to reduce this suppressive effect, which supports the concept of a ‘human shield’, where animals stay near people as predators avoid those areas. Jackals tend to avoid developed areas in regions where wolves are absent, but are more likely to occur near humans where wolves are present. Jackals currently occur mostly in southeastern and central Europe (although some individuals have been found as far west as Spain and as far north as the Arctic), but the authors found that 75% of the total area of the continent is environmentally suitable for this species.

The authors note that, although ongoing wolf recovery in Europe may reduce suitable areas for jackals, the persistent ‘human shield’ effect — combined with climate change and land-use modification — is likely to continue facilitating their expansion.