Alpine swifts (Tachymarptis melba) can spend over six months flying continuously during trans-Saharan migration, according to research published in Nature Communications. The work suggests that all vital physiological processes, including sleep, can be perpetuated during flight.
To fly is a very costly activity, compared with being in the ground or in the water. To date, migrating birds have been thought to spend some time resting on the ground or on water to recover during long distance flights associated with migration.
Felix Lietchi and co-authors present evidence of a 200-day non-stop flight from three individuals of Alpine Swift in their trans-Saharan migration between Europe and Western Africa. The authors equipped the swifts with GPS data loggers, able to measure the location of the animal and the level of activity. Based on the stored data, they reconstructed the birds’ non-breeding movements and activity pattern over a period of at least seven months. They noted that, over a period of 200 days, the birds were active, and either gliding or flapping their wings. This led to conclude that the birds did not stop for a rest in 200 days even after flying a distance over 2,000 km. In addition, the activity pattern revealed that the swifts can stay airborne continuously throughout their non-breeding period in Africa and must be able to recover while airborne. Up to now, such long lasting locomotive activities had been reported only for animals living in the sea.