Northen Hawk owl- Gwalchdylluan
Order Strigiformes
Family Strigidae
Genus Surnia
The Northern hawk owl is such a unique small species of owl, weighing 345g that even from 23 deceased specimens ,is poorly understood with regards to how this owl evolved and lineage. This species has a circumpolar, distribution from Norway, across the Soviet union, and into Eastern Canada. It is a common species of the Boreal and Taiga forests, however subject to population fluctuations and may at times be rare. The owl is a local resident and does not regularly migrate, but due to population eruptions, similar to that of the long eared owl, it can be found again out of its normal range. However this species is subject to food related movements which can cause it to be found outside its normal range. This owl is atypical of most owl species because like a hawk it hunts during the daylight hours using sight more than hearing to locate prey. Very similar to small Accipiters. It is the only owl species with small symmetrical ear openings, whilst all other owls are asymmetrical.
The northern hawk owl is named thus due to similarities and behaviors, and appearance with typical hawks, having small yellow eyes, the wings are large and tapered, unlike those of most owls and when in flight that with its long tail and very swift flight it appears very hawk like. it behaves like a hawk rather than an owl, and has a much notable flatter head than owls. size 18″ long and with a wingspan up to 28″ commonly confused due to its barred markings to to barred owl, however barred owls lack the ocelli and black outline around the face
northern hawk owls have incredible vision spotting prey up to almost a mile away, and are very quick to respond, making direct persuit attacks reaching super speeds of up to 50mph, whilst hunting, and due to their long distance hearing they can locate their prey 1 ft deep under snow cover.
They are generally solitary, but can be seen in pairs. They are highly vocal and known for their distinctive, far carrying trilling ululululululu that peaks around 14 seconds, before winding their song down. males will use this song in the spring to attract females. they also have up eight different vocalizations, one is a hawk like chattering, ki ki ki which is repeated around 12 times and sounds more like a little parrakeet than an owl.
The Northern hawk owl is often found perched on top of a tree, or low down in a shrub, from which it can scan, large open areas for its prey in daylight however in the winter being circumpolar it also hunts at night. however its hearing is not as so well developed like other owls, and uses the moonlight reflecting off the snowfields, to assist vision. it can have several caches in its territory of stored food to see this owl through colder nights.
The northern hawk owl does not build a nest and lays its eggs in cavities, in broken tops of rotten trees, and this owl is not afraid of human activity and nests near human settlements, the tolerance of man and urban disturbances is again unusual as these owls are territorial and the closest distance to man and nests has been found between just 132yards.
This owl lays between 3-12eggs, depending on scarcity or abundance of food. only the female incubates the eggs, the male does all the food provision, and also usually perches away from the nest within 100-200 yards. Incubation starts when the first egg is laid and hatching occurs 28-32 days later. They become very aggressive once their young leave the nest.
The Northen hawk owls diet is rather varied for a small owl, similar in size to our long eared owl. 94% of their diet is red backed voles and mice, however this owl will take invertebrates and mammals as large as young snowshoe hare, ptarmigan, squirrels, birds such as the northern flicker, From larger prey they are known to only eat the visceral fat from around the organs for energy whilst also caching the rest. The northern hawk owl will cast a pellet of undigestible parts of its meal, usually bone, feather and hair, and may also contain insect chitin,
The main predators of the northern hawk owl, are great horned owls, and northern goshawks, smaller birds will harass and mob northern hawk owls when they are hunting, though this harrassment does not lead to physical injury due to the fact, the northern hawk owl gives good warning to those by bobbing its long tail similar to that of a cuckoo, and the fact the have ocelli, markings adorned on the head feathers, that appear as a false face and eyes, you never really can tell from a distance which way the owl is looking, which small birds play caution to as they usually attack from behind the head, the northern hawk owl always looks like it is wearing a protective helmet, such a cool tactic to have acquired .In Alaska the Northern hawk owl is the only raptor present all year which hunts rodents by sight. The only conservation measure that man can take with this species, is the understanding that this owl benefits from eating agricultural pests.
The Northern hawk owl is an evolutionary outlier, uniquely bridging the gap between typical owls and hawks, indicating it has evolved a distinct lineage separated from other owls. However molecular studies indicate it is related to pygmy owls suggesting a shared ancestor, fossil records from around 6-9 mya (Miocene) show similar characteristics to the day hunting owls, that were more like hawks in habit before the mammal boom and Nocturnal habits, which existed around 68millions of years ago,
This species shows slight geographic variation, with three recognized subspecies
S.u.caparoch- North America
S.u.ulula-Northern Eurasia
S.u.tianschanica- Central Asia to Mongolia
Did you know that fossils once proved there was a Mega Northern hawk owl that existed in Europe. a 6 million, year old relative Miosurnia diurna, and identified as the earliest prehistoric ancestor to the northern hawk owl, providing insight into the evolution of daytime hunting owls.
The northern hawk owl is the only living member of its Genus.
This species is considered distinct and evolutionary specialized.
It is sometimes called the Canadian owl, or Daytime owl.
Home ranges in Europe range from 140-848 hectares, with an average 372 hectares
Terrestrial habits, open coniferous and mixed forest, forest edges and clearings, old deciduous forest burns, dense shrubby areas, especially Tamarak, swamps, scrubby second growth woodland, and muskeg.
Nests in hollow tops of dead spruce and birch
Separation distance for unsuitable habitat 10km
Separation distance for suitable habitat 10km, conservatively on larger home ranges
Separation barriers none
Evidence of reliable observation of re occurring communal roosts outside breeding season. multiple individuals roosting in reliable patch for multiple years, however for reference to this and confirmation that this species is a communal rooster, at least in two different non breeding seasons.