The autumnal migration of cranes (Grus grus) into Spain usually takes place inland, over the Pyrenees. On the last weekend of October there was an abrupt change in the weather, with temperatures plummeting and an extremely strong north wind. On Ornitho.cat, someone in Sant Andreu de la Barca (near Barcelona) recorded hearing cranes passing at 3 in the morning. This was only the beginning.
While walking in Collserola on Sunday morning, an unmistakable trumpeting made me look up to see a group of 22 cranes, circling and orienting themselves in a SW direction. The observations on Ornitho.cat came thick and fast during the day. One entry from the Delta del Ebro recorded 1,300, the observer noting the whole sky covered with skeins. The map from Ornitho.cat (yellow= 28th Oct, red = 29th) reflects this remarkable event, when the weather conditions forced the cranes into an intense coastal passage, well to the east of their usual route, much to the delight of ground witnesses.