First evidence of a 200-day non-stop flight in a bird

Being airborne is considered to be energetically more costly as compared with being on the
ground or in water. Birds migrating or foraging while airborne are thought to spend some time
resting on the ground or water to recover from these energetically demanding activities.
However, for several decades ornithologists have claimed that some swifts may stay airborne
for almost their whole lifetime. Here we present the first unequivocal evidence that an
individual bird of the Alpine swift (Tachymarptis melba) can stay airborne for migration,
foraging and roosting over a period of more than 6 months. To date, such long-lasting
locomotive activities had been reported only for animals living in the sea. Even for an
aerodynamically optimized bird, like the Alpine swift, flying requires a considerable amount
of energy for continuous locomotive control. Our data imply that all vital physiological
processes, including sleep, can be perpetuated during flight.