Rough-legged Hawk

Physical Characteristics

The Rough-legged Hawk (Buteo lagopus) is a large, long-winged raptor that breeds in the Arctic tundra and winters in open fields and prairies across North America. It is distinguished by its feathered legs and variable plumage.

• Plumage:
  Highly variable, with both light and dark morphs.

  • Light morphs show pale underparts with a dark belly band, pale head, and dark patches at the wrists on the underwings.

  • Dark morphs are mostly chocolate brown with paler flight feathers.

• Face: Pale head with streaking, a hooked bill with a yellow cere, and piercing brown eyes.

• Body: Stocky yet long-winged, with a lighter build than a Red-tailed Hawk but larger than a Broad-winged Hawk.

• Wings: Long and broad, with distinct dark “wrist patches” visible in flight. Their soaring style is buoyant and graceful, adapted for open tundra and plains.

• Tail: White with a broad dark terminal band, a key field mark when perched or in flight.

• Feet: Unique among buteos, their legs are feathered all the way to the toes, an adaptation for Arctic cold.

Size:

• Length: About 18 to 24 in (46 to 61 cm).

• Wingspan: Between 52 to 54 in (132 to 138 cm).

• Weight: Ranges from 1.5 to 3 lbs (700 to 1,400 g), with females larger than males.

The Rough-legged Hawk’s feathered legs, long wings, and distinctive wrist patches make it one of the most recognizable wintering hawks in North America.

Reproduction

The Rough-legged Hawk’s breeding cycle is adapted to the short Arctic summer, where nesting must occur quickly before winter returns.

1. Mating and Courtship:

   • Rough-legged Hawks are monogamous, often forming long-term pair bonds.

   • Courtship includes soaring flights, circling displays, and mutual calling between mates.

2. Nesting:

   • Nests are placed on cliffs, rocky outcrops, or steep slopes, overlooking tundra hunting grounds.

   • Large stick nests are lined with grasses, moss, and soft vegetation.

   • Nests are often reused and expanded each year.

3. Egg Laying and Incubation:

   • Females lay 2 to 6 eggs, whitish and often speckled with brown.

   • Incubation lasts 31 to 37 days, performed mostly by the female, while the male hunts and provides food.

4. Chick Development:

   • Chicks hatch covered in white down, brooded by the female in early days.

   • The male delivers prey to the nest, which the female tears into smaller pieces to feed the chicks.

5. Fledging and Independence:

   • Young fledge at about 37 to 45 days, though they may continue to rely on parents for food for several weeks afterward.

The Rough-legged Hawk’s breeding success depends heavily on lemming populations, with larger clutches and higher survival in years when lemmings are abundant on the tundra.

Lifespan

The Rough-legged Hawk (Buteo lagopus) is a tundra-breeding raptor whose lifespan is shaped by the harsh Arctic environment and the cyclical abundance of prey.

• Lifespan in the Wild:
  Rough-legged Hawks typically live 7 to 10 years in the wild, though some may reach 15 years or more under favorable conditions. As with most raptors, juvenile mortality is high, with many not surviving their first year due to hunting inexperience or starvation.

• Lifespan in Captivity:
  In captivity, with access to regular food and medical care, they may live up to 20 years.

Threats to the Rough-legged Hawk:

• Food Cycles: Their survival and reproductive success are tied closely to lemming and vole populations. Poor prey years can reduce breeding or lead to nest failure.

• Predation: Eggs and chicks are vulnerable to Arctic foxes, jaegers, and ravens. Adults have few natural predators.

• Human Hazards: Collisions with vehicles and powerlines, as well as habitat changes in wintering grounds, can impact survival.

• Climate Change: Alterations in Arctic ecosystems and prey cycles pose emerging risks to long-term population stability.

Despite these challenges, the Rough-legged Hawk remains widespread and stable, supported by its adaptability to migrate long distances between tundra breeding grounds and open-country wintering areas.

Eating Habits

The Rough-legged Hawk is a specialized hunter of the Arctic tundra, with its diet and hunting strategies closely tied to small mammal cycles.

• Diet:
  Their primary prey consists of small mammals, especially lemmings and voles, which can make up the bulk of their diet during breeding season. In wintering grounds, they also hunt mice, ground squirrels, rabbits, and occasionally small birds.

• Foraging Strategy:
  Rough-legged Hawks often hunt from perches or by hovering in midair over open ground, a behavior uncommon among buteos. Their long wings and buoyant flight allow them to hover like kestrels while scanning for movement.

• Hunting Behavior:
  They dive swiftly from a hover or perch to seize prey with sharp talons.
  In lemming-rich years, they may cache extra kills in the nest area for later feeding.

• Feeding the Young:
  Males deliver prey to the nest during breeding season. The female tears food into small pieces for the chicks until they are old enough to handle whole prey.

• Seasonal Variation:
  In the Arctic summer, lemmings dominate the diet. In migration and winter, prey shifts to other small mammals and birds available in grasslands, prairies, and farmland.

The Rough-legged Hawk’s reliance on rodent cycles makes it a prime example of how raptors adapt to fluctuating prey populations in extreme environments.

Uniqueness

The Rough-legged Hawk (Buteo lagopus) is a distinctive Arctic raptor with traits that set it apart from other hawks:

• Feathered Legs: True to its name, the Rough-legged Hawk has legs feathered down to the toes, an adaptation for surviving the frigid Arctic climate.

• Tundra Breeder: Unlike most buteos, it nests exclusively in the Arctic tundra, making long migrations southward each winter.

• Hovering Hunter: One of the few buteos capable of sustained hovering while hunting, a behavior more typical of kestrels and harriers.

• Plumage Variation: Displays striking light and dark morphs, with bold wrist patches and a white tail with a dark band, making it visually distinctive in flight.

• Rodent Specialist: Strongly tied to lemming and vole cycles, with reproductive success rising and falling depending on prey availability.

• Long-Distance Migrant: Migrates thousands of miles between Arctic breeding grounds and winter ranges in open fields and grasslands across North America and Eurasia.

The Rough-legged Hawk’s Arctic origins, feathered legs, and unusual hovering flight make it one of the most unique and specialized raptors of the northern wilderness.