The common swift is able to fly continuously for 10 months, without touching down for even a second, according to an extraordinary study which finds the species can stay in the air far longer than any other bird. Researchers tagged 13 common swifts and followed their every move for two years. They found that while swifts land for two months during the breeding season, it is incredibly rare for them to roost during the rest of the year, when they are migrating between Europe and Africa.
In three cases, the bird didn’t land on the ground, a tree, water, or anything else for the whole 10 months, while none of the 13 common swifts in the study spent more than 0.5 per cent of their time out of the air. “This discovery significantly pushes the boundaries for what we know about animal physiology. A 10-month flight phase is the longest we know of any bird species, it’s a record,” said the lead author of the study, Professor Anders Hedenstrom, of Lund University in Sweden.
Dr Hedenstrom says he was astonished by the results of his study, published in the journal Current Biology. “I was surprised. It had been speculated that they may spend the whole non-breeding period airborne because no one had ever found a roosting site. But Africa is very big and they do spend a lot of time in the remote Congo rainforest so I had kind of expected they roosted there,” he added.
Common swifts typically weigh 35 to 40 grams, are 18cms long and have a wingspan of around 40cms.
The researchers used a microdata log, attached to each bird, to determine whether the birds were in the air or not, their acceleration and where they were at any given time.
Alpine swift: A relative of the common swift, this species is thought to be the second longest flyer, with researchers finding they can remain airbourne for around six months at a time.
Albatross: These giant birds are known for spending months at a time at sea. However, for much of this they are perched on the sea looking for squid. Still, they can last a couple of days without touching down, which is particularly impressive given their size.
Great frigatebird: This sea bird doesn’t have waterproof plumage so can’t land on the sea but can spend up to two months in the air.