A letter recently published in Nature by Antoni Margalida (see below) discusses the relatively new issue of collisions between commercial aircraft landing at Barajas airport (Madrid) and griffon vultures – in the last decade there were 26 such accidents. Also three fatal accidents occurred with non commercial aircrafts between January-June 2016.
According to Margalida, this situation could be due to birds exploring new foraging areas following changes in European health regulations in 2002, that forced farmers to destroy any dead carcasses in the field. Griffons have thus started then to feed on landfill sites and this has brought them closer to Barajas, although the cause-effect is not clear and should be investigated. The EU regulation was subsequently updated to allow again for dead cattle to be given to the vultures in supplementary feeding sites or be left in the fields in certain areas.
The griffon vulture population in Spain has also increased significantly in the last few years.
You can download the letter here -
Photo Bruno Berthémy-VCF