An ecological solution is needed to prevent collisions of Eurasian griffon vultures (Gyps fulvus) with aircraft in Spain, home to some 95% of Europe's population of these large raptors. There were 26 such collisions recorded in 2006–15 around Madrid Barajas airport, which handles about 47 million passengers each year, and 3 light-aircraft strikes in the first 6 months of 2016.

This surge could be explained by the birds' relocation away from their usual feeding areas, following changes in European health regulations in 2002 (see A. Margalida et al. Nature 480, 457; 2011). Those rules forced farmers to collect and destroy livestock carcasses, an important food source for vultures.

The birds have since scavenged in areas such as landfill sites. When these are located inside air-traffic corridors (where aircraft fly below 1,200 metres), the risk of collision increases. The negative effects of the 2002 health regulations on vulture populations and demography are being tackled (see go.nature.com/2ap6zsd), but not fast enough to avert aerial collisions.

To manage the situation more effectively, we need a better understanding of the movement ecology of vultures around sensitive areas, the spatial distribution of their food resources and a warning system that detects vultures entering air-traffic corridors.