Common swifts can fly for ten months without landing

 I knew that bird can fly for a large distance, but 10 months... But they have to fly in winter to the south so its understandeble.

Common swifts are medium-size aerial birds known for their superb flying ability. They are entirely blackish-brown in color except for a small white or pale grey patch on their chins which is not visible from a distance. They have a short forked tail and very long swept-back wings that resemble a crescent or a boomerang. I think they can fly on long distances wiht a help of this wings.