The rough-legged hawk is a large bird of prey found primarily in the northern regions of North America, Europe, and Asia. It is one of three species of hawks in the genus Buteo, known as buzzard hawks. During the breeding season, rough-legged hawks inhabit the Arctic tundra. In winter, they migrate south to more temperate regions with open terrain. Their impressive migration can cover thousands of miles from their summer breeding grounds to wintering habitats and back again each year.
Rough-legged hawks are easily identified by the feathered legs that give them their common name. These long leg feathers help them stay warm in frigid northern climates. They also have distinctive color patterns with dark brown upperparts and white underparts, as well as black wrist patches on otherwise pale wings. Rough-legged hawks feed mainly on small mammals like lemmings, voles, and squirrels which they hunt while hovering and soaring over open country.
Breeding Range
During the spring and summer breeding season, rough-legged hawks are found throughout the Arctic regions of northern North America, Europe, and Asia.
In North America, they breed from northern Alaska across northern Canada to Labrador and Baffin Island. Their breeding range extends as far south as southern Yukon and Northwest Territories in western Canada to Quebec in eastern Canada.
In Europe, breeding populations are found throughout arctic regions including Iceland, Scandinavia, and northern Russia. They breed as far south as Scotland and the Baltic coast.
Asian breeding grounds extent from the Russian Far East west through Siberia. Their range stretches as far south as northern Mongolia and northeastern China.
Rough-legged hawks inhabit open tundra, mountain heaths, bogs, and shorelines within these northern breeding areas. They nest on rocky outcrops, cliffs, and crags, as well as in trees along river valleys where available.
Alaska and Northern Canada
In Alaska, rough-legged hawks breed primarily north of the Brooks Range including coastal regions of the Arctic Ocean and Arctic foothills. They occur less commonly in interior and southern regions of the state.
They are found throughout the northern Yukon, Northwest Territories, and Nunavut in northern Canada. Their highest densities occur from the Mackenzie River Delta east to Hudson Bay where small mammal populations thrive on the extensive tundra.
Scandinavia
In Scandinavia, most of the breeding population is concentrated in northern Norway including Finnmark county and northward. Rough-legged hawks also breed in northern Sweden and Finland above the Arctic Circle as well as in low numbers in northern Russia near the Scandinavian border.
Some breeding occurs farther south along the coast of central Norway. The population in Iceland breeds mainly in the northern and eastern parts of the island.
Russia
In Russia, rough-legged hawks primarily inhabit Arctic tundra from the Kola Peninsula east across the Taymyr Peninsula to the Chukotka Peninsula. Their breeding range extends as far south as the northernmost part of the Kamchatka Peninsula in the Russian Far East.
They are numerous along the coastal lowlands of the Yana, Indigirka, and Kolyma rivers of northeastern Siberia. Breeding also occurs on Wrangel Island, Herald Island, and other Arctic islands off the coast of Siberia.
Wintering Range
During the fall and winter months, rough-legged hawks migrate from their Arctic breeding grounds to more temperate regions of North America and Eurasia. These wintering areas provide the hawks with more favorable conditions and access to prey.
North America
In North America, rough-legged hawks winter primarily in southern Canada and the northern United States. The majority of the population winters in the Great Plains from Alberta to Manitoba southward to Texas and Louisiana.
Other important wintering areas include interior Alaska, British Columbia, the Great Basin region, the Columbia River Basin, and northern California east of the Sierra Nevada. Some winter along the Atlantic Coast from southern Quebec and Maine south to Virginia.
Europe and Western Asia
European and west Asian wintering grounds span from Belgium and the Netherlands east through central Europe and the Baltic region to Russia and Kazakhstan. The highest concentrations are found from Germany through Poland and Belarus as well as northern Ukraine and southern European Russia.
Some winter as far north as southern Sweden and Finland when lemming populations crash farther north. In mild winters, increasing numbers overwinter in Great Britain.
Eastern Asian wintering areas extend from northeastern China across the Korean Peninsula to Japan. Rough-legged hawks are also present in lesser numbers in winter in central Siberia between Lake Baikal and the Lena River.
Habitat
Rough-legged hawks prefer open habitats like grasslands, agricultural fields, coastlines, and tundra while wintering. They perch on utility poles, trees, fence posts, or mounds of dirt to hunt.
Some key wintering areas include mixed-grass prairies of the Great Plains, shrub-steppe of the Great Basin, coniferous forests of the Pacific Northwest, and agricultural regions of California’s Central Valley.
Migration
Rough-legged hawks undertake long distance migrations in fall and spring between their breeding and wintering grounds. Some populations migrate over 5,000 miles (8,000 km) round trip each year.
They migrate through a wide front across North America in loose flocks, also known as kettles. In Europe and Asia, they migration pathways are concentrated within certain flyways.
Fall Migration
The fall migration from the breeding grounds starts in late August and September. Juveniles tend to leave first followed by adult females and adult males.
In North America, hawks leaving Alaska traverse west through Asia or east across northern Canada. Birds follow three main routes from Canada towards wintering grounds:
– Central Flyway – Along the Rocky Mountains through the Great Plains
– Mississippi Flyway – Across the Great Lakes region to the Mississippi River Valley
– Atlantic Flyway – Over eastern Quebec, the Maritimes, and New England
European birds migrate southwest over Scandinavia towards wintering areas in western and central Europe. Asian populations migrate south from Russia into northeastern China, Korea, and Japan.
Spring Migration
The northern migration to the breeding grounds occurs over a broader front. It takes place from March to May in North America and February to April in Eurasia.
Migrating flocks mix individuals from different wintering areas across breeding ranges. For example, hawks wintering in the western United States disperse across Alaska and northwestern Canada to nest.
Adults tend to arrive on the breeding grounds first and are followed by subadults and juveniles. Birds exhibit strong breeding site fidelity, returning to prior nesting locations annually.
Threats and Conservation
Rough-legged hawk populations are generally stable and the species is evaluated as Least Concern on the IUCN Red List. However, they face some threats particularly on their breeding grounds.
Climate Change
The effects of climate change could degrade tundra habitat in the Arctic region. Increases in temperature, precipitation, and shrub growth may reduce nesting and hunting areas.
Range shifts northward are likely to occur but could impact breeding success and survival depending on prey availability and conditions in new northern habitats.
Development
Expanding oil and gas development and mining in the Arctic poses risks of disturbance, habitat loss, and contamination from spills. The impact on remote breeding areas is largely unknown.
Wind power infrastructure may also negatively affect hawks through habitat modification, displacement, and collision mortality during migration and wintering periods.
Pesticides
High levels of pesticides and other contaminants from agricultural and industrial chemicals have been detected in rough-legged hawks. Exposure can cause eggshell thinning along with potential impacts on reproduction and survival.
More research is needed on contaminant accumulation patterns and population-level effects. Targeted restrictions on the most harmful chemicals may be warranted.
Conservation Actions
While still common, focused conservation efforts for rough-legged hawks may be needed to protect breeding and wintering habitats given emerging threats.
Future priorities include more robust population monitoring across their range along with reducing contaminants and mitigating climate change impacts through ecosystem management and clean energy policies.
International cooperation is key to conserving these long-distance migrants as they traverse Remote nesting areas, migration routes, and widespread wintering regions across the northern latitudes of North America and Eurasia.
Conclusion
In summary, rough-legged hawks inhabit the tundra regions of the Arctic during the breeding season before migrating south to wintering grounds in the temperate zone. Their range spans northern North America from Alaska to Canada, northern Europe and Russia, and parts of Asia.
While populations currently appear stable, new threats from climate change, development, and pollution in both their breeding and non-breeding habitats may emerge. Targeted conservation efforts focused on protecting key habitats and mitigating these threats will help ensure the long-term survival of these impressive migrants.