Owl Owl Owls are birds from the order Strigiformes, which includes about 200 species of mostly solitary and nocturnal birds of prey typified by an upright stance, a large, broad head, binocular vision, binaural hearing, sharp talons, and feathers adapted for silent flight. Exceptions include the diurnal northern hawk-owl and the gregarious burrowing owl. Owls hunt mostly small mammals, insects, and other birds, although a few species specialize in hunting fish. They are found in all regions of the Earth except polar ice caps and some remote islands. Owls are divided into two families: the true (or typical) owl family, Strigidae,
Dusky crag martin species are members of the swallow family of birds, and are classed as members of the subfamily Hirundininae which comprises all swallows and martins except the very distinctive river martins. DNA studies suggest that there are three major groupings within the Hirundininae, broadly correlating with the type of nest built. The groups are the "core martins" including burrowing species like the sand martin, the "nest-adopters", which are birds like the tree swallow that utilise natural cavities, and the "mud nest builders". The "Ptyonoprogne" species construct an open mud nest and therefore belong to the latter group; "Hirundo" species also build