10 Months

Watching swifts do a number on insects over an open field is a transcendent experience of seeing how flight becomes magical in a tiny bird that fits in the palm of one hand. What's even more astounding is the fact they can fly for nearly 10 months without touching the ground.

Scientists had long ago proposed that common swifts, a medium-sized migratory bird, might spend most of their lives in flight, but it is only now that it is proved that these birds can actually fly for 10 months straight.

"This discovery significantly pushes the boundaries for what we know about animal physiology," lead author Anders Hedenstrom of Lund University in Sweden, said in a statement on Saturday.

"A 10-month flight phase is the longest we know of any bird species -- it's a record."

Previously, scientists have found frigate birds and alpine swifts can remain in flight for up to seven months.

"They feed in the air, they mate in the air, they get nest material in the air," researcher Susanne Åkesson from Lund University in Sweden tells National Geographic. "They can land on nest boxes, branches, or houses, but they can't really land on the ground."

The birds' shape contributes to this finding; their "wings are too long and their legs are too short to take off from a flat surface," the magazine reports.

The researchers suggest that one driving force behind the bird's incredibly long flights could be its diet. "[S]pecializing in high-altitude aerial insects as a main food source requires the suite of adaptations for efficient flight shown by swifts, ... which compromises terrestrial locomotion and make swifts vulnerable to predators and parasites had they been landing more often," the paper states.

On a Wing but Nota Prayer :) is a BRT piece on the Frigate Bird, the 2nd greatest flyer in the world.