The northern hawk owl (Surnia ulula) is a medium-sized owl that inhabits the boreal forests of North America and Eurasia. In North America, northern hawk owls are found primarily in Canada and Alaska, with small populations in the northern United States. They occupy a variety of forest habitats, including both coniferous and mixed deciduous-coniferous forests. Here is an overview of where northern hawk owls are found across their range.
Canada
Canada hosts the majority of the world’s northern hawk owl population. They are found across much of the boreal forest region from Yukon and Northwest Territories east to Newfoundland and Labrador. Some key facts about the distribution of northern hawk owls in Canada:
- Yukon and Northwest Territories: Northern hawk owls occupy the boreal forests across these territories. They are a year-round resident.
- British Columbia: Found in the central and northern interior of BC in boreal forest regions. More common in the northern half of the province.
- Alberta: Present primarily in the northern boreal and foothills natural regions. Largest populations are in the northwest.
- Saskatchewan and Manitoba: Distributed across the boreal forests of the provinces. Most abundant in central and northern regions.
- Ontario: Found in the Hudson Bay Lowlands and boreal forest regions across the northern half of the province.
- Quebec: Occurs in the boreal forest across the central and northern part of the province. More numerous in western regions closer to the core of their range.
- Newfoundland and Labrador: Restricted to the boreal forest areas across Labrador. Absent from the island of Newfoundland.
In general, northern hawk owl distribution closely matches the extent of boreal forest across Canada. They are less common in eastern provinces further from the core of their range.
Alaska (United States)
The northern hawk owl is a year-round resident of the boreal forest region of Alaska. They occur throughout mainland Alaska, as well as the Aleutian Islands. Population densities are highest in interior Alaska.
United States (excluding Alaska)
In the lower 48 United States, the northern hawk owl occupies a narrow band of boreal forest habitat along the northern border with Canada. Populations in the contiguous US are sporadic and vulnerable. Key areas include:
- Northern Minnesota: Occurs irregularly in the boreal forest region near the Canadian border. Population estimates range from 10 to 100 pairs.
- Northern Wisconsin: Rare and local resident. Estimated 20-40 pairs total.
- Western Montana: Found in boreal forest areas on the Rocky Mountain Front. Uncommon, estimates of less than 100 pairs.
- Northern Idaho: Rare resident with less than 10 known pairs occupying boreal habitat.
- Maine: Rare and declining. Few recent confirmed records, likely less than 10 pairs remaining.
- Northern New Hampshire: Accidental reports only in recent decades.
While widely distributed across Canada’s boreal forests, northern hawk owl populations in the lower 48 states are extremely localized and vulnerable. Habitat loss is a major threat to the remaining southern populations.
Eurasia
Northern hawk owls have a circumpolar distribution, also occupying boreal forest regions in Eurasia. Their range includes:
- Northern Europe, including Norway, Sweden, Finland, and Russia
- Northern Asia, including Russia and Mongolia
As in North America, northern hawk owls closely follow the boreal forest habitat. They are found across Russia and northern Scandinavia. Population densities are lower in Europe compared to Siberia. They are typically restricted to higher latitude boreal regions.
Preferred Habitats
Within their broad boreal forest distribution, northern hawk owls show habitat preferences that influence their local distribution and abundance:
- Open and semi-open forests – Northern hawk owls hunt by sight during the daytime. They prefer more open boreal woods with less dense understories.
- Recently burned areas – Forest fires create ideal habitat with abundant prey and perches for hunting. Northern hawk owls often concentrate in recently burned boreal forest.
- Forest edges and openings – Natural forest openings and edges, such as along rivers, lakes, and wetlands, are preferred hunting grounds.
- Coniferous and mixed forests – They most often occupy conifer-dominated or mixed deciduous-coniferous boreal habitat.
- Avoids pure deciduous stands – Broadleaf deciduous forests tend to have a denser understory and are avoided.
Northern hawk owls are flexible in using a variety of boreal forest types. But within these, they prefer more open habitats that support their specialized hunting behavior.
Elevation
Across most of its range, the northern hawk owl occupies lower elevation boreal forest, primarily at elevations below 1,000 meters (3,300 feet). A few key points about elevation preferences:
- They are typically considered a lowland species, avoiding higher elevations mountains.
- However, in Alaska they may occupy boreal habitat on mountain slopes up to around 1,500 m (4,900 ft).
- They are also found at higher elevations in the southernmost parts of their range where boreal forest occurs at higher altitudes (e.g. 900-1,800 m in Idaho).
While flexible, northern hawk owls generally occur at lower elevations characterized by boreal forest habitat. They are often described as a lowland boreal species relative to boreal owl which occupies higher elevation boreal habitat.
Population Irruptions
One unique aspect of northern hawk owl distribution is irregular population irruptions and winter migrations. When prey is scarce in their normal range, northern hawk owls may migrate south and expand into peripheral areas in search of food. This includes moving further south in the northern U.S. and southern Canada. Some major irruptions and range expansions include:
- 1972-73: Major southward movement into prairie provinces of Canada and northern U.S. Midwest and Northeast.
- 1978-79: Large numbers moved south to Great Lakes region and New England.
- 2003-04: Big irruption to southern Canada, northern Minnesota, Wisconsin, and Michigan.
- 2013-14: Another large surge into the Great Lakes region.
These irruptive movements are episodic and occur in winters when prey populations crash in the core boreal range. While northern hawk owl distribution is tied closely to boreal forest, irruptions demonstrate the flexibility to occupy peripheral habitats when needed.
Conclusion
In summary, northern hawk owls have a circumpolar distribution closely associated with boreal forest habitat. Their primary range spans the boreal zone of Canada and Alaska, as well as northern Eurasia. Small peripheral populations occur in the contiguous United States. Within their boreal forest range, they prefer open and semi-open forests that support their specialized daylight hunting. Northern hawk owls also demonstrate the ability to irrupt outside of typical range in search of prey during winter.