Whether the bird resides in Eurasia or North America, the strategy is usually similar. Classification, To cite this page:  Although most owls have these characteristics, certain species such as the burrowing owl and the northern hawk-owl do not have them. , S. ulula has a variety of calls used by the different sexes in different situations. 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.  However, it is unknown what effects modern forestry would have on population levels because although it would decrease nesting localities, it would simultaneously create ideal habitat for Microtus prey. Hawk owls do not tend to be found in close proximity with cities. Other animals that are preyed on by the owl are: lemmings, mice, birds like doves, sparrows, etc. The northern hawk-owl will perch and scour the immediate area for prey. Northern Hawk Owls' plumage is compact, in contrast to the down feathers of boreal owls (Voous, 1988). at http://owling.com/N-Hawk_nh.htm. Pp. It prefers mountainous ranges where open areas and perches are readily available. Theories suggest that this enables the female owl to dismember its prey better – so she can feed the creature to its young right after. , The northern hawk-owl generally starts its mating rituals at the beginning of March.  S. u. caparoch can occasionally be found in more southern areas such as Great Britain, southern Russia and Scandinavia, following explosions of prey. breeding is confined to a particular season, reproduction that includes combining the genetic contribution of two individuals, a male and a female. Females are slightly bigger with a length of 37.2–44.7 cm (14.6–17.6 in) and a mass of about 340 g (12 oz).  In 1991, Schmutz and Moker first reported the karyotype of the northern hawk-owl and found it to resemble considerably that of the genus Athene. Cambridge, Massachusetts: MIT Press. Eggs, nestlings and fledgings may be preyed on by foxes, coyotes, wild or feral cats and racoons and their cousins. Expected lifespan in both captivity and wild is 10 years (Duncan and Duncan, 1998). A male establishes its territory a few weeks before nesting and attracts a female to the nest site through an Advertising Call (Duncan and Duncan, 1998). Northern Hawk Owl’s are a bit unusual because they aren’t nocturnal. The extent to which they prey on birds is unknown. having body symmetry such that the animal can be divided in one plane into two mirror-image halves. The specific dates of egg appearance can be quite variable depending on locality. They feed on small rodents and mammals, and a variety of birds. It has been suggested that this may be because the hawk-owl may partially fill an important diurnal niche similar to that of day hunters such as hawks. They hunt both during the day and the night (Duncan and Duncan, 1998). (2000) considered the hawk-owl to be of medium concern, but with a high priority to improve monitoring. At about two weeks into the chicks' lives the female starts to leave the nest for long spans of time (5 hours or more). These environments include sphagnum bogs and partially deforested areas. They hunt primarily during the day, which means that they identify prey by sight and their hearing isn’t as acute as other owl species’. After calling and pairing is complete the northern hawk-owl will build a nest and start to lay eggs.  The North American subspecies S. u. caparoch spans from eastern Alaska through Canada to Newfoundland and in some areas extends south into northern United States.