Migration is one of birds' most observable behavior annually traveling from one continent to the next for months at a time. For years, scientists knew that there are species that is able to remain airborne for up to six months. New research revealed, however, that there are those that can constantly fly for up to 10 months, a feat achieved by the common swift bird.
Common Swift Bird Can Sleep During Extensive Flights
This avian species is ubiquitously found in U.K. and Europe. Ornithologists, people who study birds, have long suspected that the swift spends most of its life in the air although concrete proof hasn't been available until now. To collect evidence, researchers attached sensors and data loggers on 19 common swifts and observed them complete their annual migratory cycles from Europe to sub-Saharan Africa.
As they track their specimens the loggers indicated that among 19 of them, three have not touched the ground at all. While the others did land, researchers suspect that this was because of bad weather and if not for those the birds would be able to remain in flight until it reached their destination. Anders Hendenstrom, the lead researcher and biology professor at Lund University, expressed his astonishment after discovering the common swift's bird's "mind-boggling" behavior.
But what's even more remarkable is the fact that the birds don't need to land in order to sleep, which can only mean they take a shut-eye during their extended flights. This finding is backed by data collected that the bird would climb 10,000 feet in the air twice a day, usually during dawn and dusk. The altitude would allow the birds to make a slow descent giving them the opportunity of a half an hour worth of sleep, the Telegraph reported.
Other avian species that practice these constant flying behavior is the Alpine Swift, which was previously thought to be the longest bird to remain in the air with a six-month flight record. The frigate bird follows behind with a two-month flight time and could travel for 40 miles without a single wing-flap, the NPR reported. Scientists also noted that the common swift bird breaks a biological rule.
"Most of the time there is a trade-off between energy use and life: live hard and die young," said Hendenstrom. However, the common swift has been observed to live as long as 20 years. The biology professor said that the next step for them is to determine how long exactly do these birds sleep during their exhausting annual journey.