The Northern Hawk-Owl (Surnia ulula) is a medium-sized owl known for its distinctive appearance and diurnal habits. It is the sole living species in the genus Surnia within the family Strigidae, which includes the typical owls. This bird of prey exhibits a striking resemblance to hawks, particularly in flight, and is active during daylight hours, unlike many of its nocturnal relatives.
Males typically measure 36–42.5 cm in length and weigh around 300 grams, while females are slightly larger at 37.2–44.7 cm and approximately 340 grams. Both sexes have a wingspan of about 45 cm. The plumage is dark brown with off-white spotting on the dorsal parts, except for a black V-shaped pattern on the back of the neck. The underbelly is white or off-white with brown banding. A smokey white face with a black border, flat head, yellow eyes, and a yellow curved beak are characteristic features.
The Northern Hawk-Owl favors open coniferous forests and mixed woodlands, including larch, birch, poplar, and willow. It can also be found in muskegs, clearings, swamp valleys, meadows, recently burnt areas, and generally avoids dense spruce-fir forests.
This owl is native to the northern Holarctic, with three recognized subspecies: S. u. tianschanica in central Asia, S. u. ulula in northern Eurasia, and S. u. caparoch in northern North America. It is non-migratory but may irrupt southward, especially during winter or following prey population booms.
The Northern Hawk-Owl is known for its hawk-like behavior and hunting strategies. It perches in open environments to scan for prey and may dive or glide with a few wing flaps to capture its target. It has excellent hearing and can even catch rodents beneath the snow.
Males emit a rolled whistle and a series of tu-wita-wit calls when courting, while females have a more shrill call. Alarm calls include a rike series and a high-pitched scream followed by a yip near the nest.
Breeding begins in early March, with nests typically located in hollow stumps of dead trees. The female incubates the eggs, and both parents are involved in rearing the young, which leave the nest after about three weeks.
The diet consists of small to medium-sized mammals and birds, with a preference for voles and, in North America, snowshoe hares. The owl eviscerates its prey and may cache remains for later consumption.
The Northern Hawk-Owl is classified as Least Concern by the IUCN, but its remote breeding locations and low density make it one of the least studied birds. Its populations fluctuate with prey cycles, and the effects of modern forestry and fire suppression on its numbers are not well understood.
In North America, the Northern Hawk-Owl's flight appearance can be confused with the Cooper's hawk (Accipiter cooperii) due to its similar size and hunting style.
In certain regions like Ontario, the Northern Hawk-Owl is recognized as a falconry bird and may be used for hunting small game with appropriate licensing.