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”.
The genus name Surnia appears to be a word made up by A. M. C. Duméril, the creator of the genus, and ulula is Latin for a screech owl
Northern hawk-owls are unevenly distributed and highly variable throughout the boreal forest. They live mostly in open coniferous forests, or coniferous forests mixed with deciduous species such as larch, birch, poplar, and willow. They are found in muskegs, clearings, swamp valleys, meadows, or recently burnt areas, and generally avoid dense spruce-fir forests. Winter habitat is usually the same as breeding habitat.