Scanning electron micrograph (SEM) of a feather from a lanner falcon (Falco biarmicus). The feather has a central shaft, or rachis, which branches into numerous parallel barbs. The barbs themselves branch into thin parallel barbules, which terminate in tiny hooks (barbicels), which attach to the adjacent barbule. These links allow the feather to present a flat blade. The lanner is a large falcon that inhabits open country in Africa, southest Europe and western Asia.