Maximum number of Griffon Vultures ever recorded on active migration in a single day at the Strait of Gibraltar

Abstract

The Strait of Gibraltar is the most important bottleneck for Griffon Vulture (Gyps fulvus) migration in the Palaeartic but its monitoring has been irregular during the last four decades. The breeding population in Spain and the number of vultures recorded migrating across the Strait have both increased, as has the knowledge about their migratory routes, favourable migratory weather conditions and this species’ overall phenology. Despite this, the Griffon Vulture is still one of the least monitored major species in the Strait of Gibraltar. On assessing the weather forecasts during the autumn of 2015 it was predicted that the 28th October was a possible vulture migration “D- Day”. The resulting total was an impressive 2,362 Griffon Vultures arriving on the Moroccan side of the Strait of Gibraltar; the biggest number ever recorded in a single day for this species.