Ornithologists reported the longest recorded flight made by any bird -- a non-stop, more than 200-day journey across the Sahara.
What's more, the trip was not made by one bird, but three Alpine swifts, each of which made the 1,240 mile journey without landing to rest or even sleep. Food came in the form of mid-flight insects the swifts gobbled up en route. Ornithologist had long suspected the Alpine swift was capable of such long-distance flights, but the hard data had never been recorded until now.
A special type of sensor developed at Bern University was used to collect data on the birds' acceleration, its pitch (the angle of its body relative to the ground) and any light hitting the bird, the Smithsonian blog reported. The light data could be used to infer latitude based on the timing of sunrise and sunset.
Researchers were able to use the data collected by the sensor to determine whether the birds were flapping their wings, gliding or resting on the ground.
"They stayed in the air for all time they spent south of the Sahara, day and night," Felix Lietchi of the Swiss Ornithological Institute, told the Smithsonian. "Sometimes they just glide for a few minutes, so there's no movement, but the pitch of the body indicates that they're still gliding in the air."
Lietchi and his colleagues said they were "totally blown away" when the data revealed that the birds stayed in the air for more than 200 consecutive days.
The sensors only recorded data every four minutes, so there is the possibility that the birds could have quickly landed and took off again before the next data cycle, but every data point collected for more than six consecutive months indicated the birds were in the air, either gliding or flapping their wings.
It's difficult for the researchers to determine precisely how the swifts rest while in flight, but the data suggest the birds are capable of resting mid-air.
Other birds, such as the albatross, are known for flying days on end without landing, resting one hemisphere of their brain at a time.
"It's fascinating," Lietchi said of the Alpine swifts, "and it opens up a whole new window for us into these species."
Lietchi and his colleagues' research is published in the journal Nature Communications.