Answer: Common Swift

When you think of a bird that spends its life on the wing, it would be easy to focus on huge birds, like the wandering albatross, that can effortlessly glide for several hours without so much as a pump of their broad wings. The reality, however, is quite different: the bird that spends most of its life and certainly the longest spans of time aloft is the common swift.

Except for their time nesting to raise a new brood, common swifts spend practically every moment of their lives in the air. They eat insects they catch during flight, drink moisture that condenses on their wing feathers, they even mate and sleep (bursts of microsleep), all while in the air. In fact, researchers attached tiny data trackers to groups of swifts and found that many of them stayed aloft for upwards of ten months at a time, typically only stopping to roost because extreme weather briefly grounded them.

Not only do they spend nearly their entire lives aloft, but they are quite speedy—their very name, swift, is well earned as they have a maximum horizontal flying speed of 69.4 miles per hour (111.6 kilometers per hour), and over the course of their lives, they can easily cover millions of miles in flight.