Swifts already hold the title of the fastest fliers on Earth and now the small soot-brown birds have been revealed as one of nature’s greatest endurance athletes, after scientists discovered they spend ten months of the year entirely airborne.

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Swifts already hold the title of the fastest fliers on Earth and now the small soot-brown birds have been revealed as one of nature’s greatest endurance athletes, after scientists discovered they spend ten months of the year entirely airborne.