The northern hawk-owl or northern hawk owl (Surnia ulula) is a medium-sized true owl of the northern latitudes. It is non-migratory and usually stays within its breeding range, though it sometimes irrupts southward. It is one of the few owls that is neither nocturnal nor crepuscular, being active only during the day. This is the only living species in the genus Surnia of the family Strigidae, the "typical" owls (as opposed to barn owls, Tytonidae). The species is sometimes called simply the hawk owl; however, many species of owls in the genus Ninox are also called "hawk owls". Taxonomy The northern hawk-owl was formally described by the Swedish naturalist Carl Linnaeus in 1758 in the tenth edition of his Systema Naturae under the binomial name Strix ulula. The owl is now the only species placed in the genus Surnia that was introduced in 1805 by André Duméril. The type species was designated by George Robert Gray in 1840 as the northern hawk-owl. The genus name is of unknown etymology and may simply have been invented by Duméril. The specific epithet ulula is Latin for a "screech owl". A molecular phylogenetic study of the owls published in 2019 found that the northern hawk-owl is sister to a clade containing the pygmy owls in the genus Glaucidium. Three subspecies are recognised: S. u. tianschanica Smallbones, 1906 – central Asia to northern China and northern Mongolia S. u. ulula (Linnaeus, 1758) – northern Eurasia S. u. caparoch (Müller, PLS, 1776) – northern North America Description Male northern hawk-owls are generally long and weigh about . Females are slightly bigger with a length of and a mass of about . Both male and female have similar wingspans of about . The northern hawk-owl plumage is relatively dark brown with an off-white spotting pattern on all dorsal parts of the body with the exception of the back of the neck which boasts a black v-shaped pattern. The underbelly is generally white or off-white which continues to the toes with brown bands on the breast and stomach. It also has a long tail with brown banding. The northern hawk-owl has a smokey white face with a black border, a flat head, yellow eyes and a yellow curved beak. The northern hawk-owl has been said to resemble a hawk in appearance and in behavior. In North America, its appearance in flight is often considered similar to a