Hen harrier and short-eared owl populations are declining across Europe. A new study drawing on expert knowledge highlights overlaps in threats faced by both species in different countries, shortcomings of current conservation strategies, and the need for international collaborative actions to save these emblematic birds of prey.

Hen harriers and short-eared owls are birds of prey that can be found across much of Europe. These two species, despite looking quite different, share many ecological characteristics: both are found in a variety of open habitats, nest on the ground, and hunt small mammals and birds. Though previously abundant, hen harriers and short-eared owls have suffered declines in recent decades and are now of conservation concern across Europe. Despite valuable efforts to study and protect these birds, this work often has a regional focus, even though populations of both species are known to be highly connected.

In our recent study published in Bird Conservation International, we bring together expert knowledge to build on work that has been carried out at a national level across Europe. Continent-wide patterns became apparent when we asked experts to rate the importance of threats faced by each species. Although some threats were more important in some areas than others, human-caused habitat change and loss emerged as the main threat to both species across Europe. Afforestation and agricultural intensification not only limit the natural habitats available to these birds but can also result in accidental destruction of nests during harvesting operations or reduced abundance of their prey species.

We also asked experts to rate conservation strategies in place for hen harriers and short-eared owl, and it became apparent that protected areas such as national parks, nature reserves, and SPA’s (special protection areas designated for these species) were the most commonly implemented strategy across Europe. However, protected areas were deemed to be less effective than proactive actions like habitat or species management (e.g. habitat enhancement and restoration, nest protection, predator control). This suggests that protected areas on their own are not enough to save these birds but need to be combined with more proactive conservation actions. These results underline how, when it comes to protecting biodiversity, we should not think that implementing conservation strategies is a final solution. It is crucial to continually review whether these strategies are working and amend them if necessary.

Overall, our study highlights the need for international initiatives to protect these birds of prey and the potential for cost-effective conservation actions that can benefit both species. For hen harriers, a Europe-wide action plan to protect the species is necessary. This should aim to address threats that are widespread and common to the different European populations, but also make space for solving region-specific problems. In light of their continued and widespread decline, it may be necessary for countries to upgrade the species’ national conservation status, and to re-assess its IUCN global conservation status. For short-eared owls, the answer is less clear. We still have a lot to learn about this species, as they are notoriously hard to monitor. Their breeding numbers can rise and fall drastically between years in response to weather and prey availability. In this sense, international studies aimed at understanding their movements and population fluctuations across Europe are a key first step.

The paper Expert knowledge assessment of threats and conservation strategies for breeding Hen Harrier and Short-eared Owl across Europe by Darío Fernández-Bellon, John Lusby, Jules Bos, Tonio Schaub, Alan Mccarthy, Anthony Caravaggi, Sandra Irwin, and John O’Halloran is available open access in Bird Conservation International.

Featured image: Hen harrier © Darío Fernández-Bellon