Red-shouldered hawk  (Buteo lineatus)

The red-shouldered hawk is classified as Least Concern (LC) on the IUCN Red List (1).

A common hawk of forested areas in North America (2), the red-shouldered hawk (Buteo lineatus) has dark brown upperparts and white or grey, red-barred underparts, with the barring being heaviest on the breast. The black tail is marked with four to six conspicuous white stripes, and there is a pale, almost translucent crescent near the wing tip. The tail and wings of the red-shouldered hawk are longer than those of other North American Buteo hawks (3). 

The juvenile red-shouldered hawk closely resembles the juvenile broad-winged hawk (Buteo platypterus), but may be distinguished by the streaking on its chest and belly. The juvenile develops the adult plumage at around 18 months of age, and the eyes turn from yellow to brown with adulthood (3). 

In flight, the red-shouldered hawk is characterised by its quick, choppy wingbeats. When soaring, the wings are slightly bowed, and when gliding, they are bowed even further (3).  

Five subspecies of the red-shouldered hawk are recognized: Buteo lineatus lineatus, Buteo lineatus alleni, Buteo lineatus extimus, Buteo lineatus texanus, and Buteo lineatus elegans. Recent genetic analysis suggests that B. l. elegans is the most genetically distinct of the five subspecies (4).

The red-shouldered hawk is found in south-eastern Canada and the eastern and western United States. Fossil remains of this species have also been found in the Bahamas, suggesting that it once occurred there too (5). 

Populations in the northern parts of the red-shouldered hawk’s range usually migrate south prior to winter, moving as far south as northern Mexico and returning north in the spring (5).

The red-shouldered hawk inhabits a wide variety of North American forests, but favours mature, mixed deciduous-coniferous woodlands, especially bottomland hardwood, riparian forest, and flooded deciduous swamps. In the western parts of its range, the red-shouldered hawk prefers riparian and oak (Quercus) woodlands, but is also found in eucalyptus groves and suburban areas with nearby woodlots (2).

The red-shouldered hawk is a dietary generalist, changing its diet to reflect the local or seasonal abundance of different prey species. It is sometimes referred to as the ‘hen hawk’; however, poultry makes up only a very minor component of its diet (6), with small mammals, reptiles, and amphibians being its preferred prey. Birds, fish and invertebrates are also occasionally eaten (7). 

Breeding occurs once a year, usually between April and July.  The red-shouldered hawk is monogamous, but a bird will seek a new mate if its partner is killed. This species builds its nest in large, mature trees, usually in a fork about halfway up the trunk, and often close to water such as along a river or stream. The nest is constructed of twigs and lined with down, and may be reused from year to year, although the red-shouldered hawk will also sometimes utilise the nest of other species. Usually, 3 (very rarely as many as 6) white or blue, heavily-marked eggs are laid, and the eggs are incubated by both adults for approximately 28 to 33 days. The chicks leave the nest at 6 weeks and become independent at 17 to 19 weeks. The red-shouldered hawk reaches sexual maturity at about 2 years of age and may live for up to 19 years (8).

The red-shouldered hawk still maintains a large range, and its population, which is already fairly large, appears to be increasing in some areas (2). This is party due to this hawk’s ability to adapt to urban environments better than many other raptors in the region (9), while forest regeneration in recent decades has also created new habitat (10). 

However, habitat loss has been a significant threat to the red-shouldered hawk in the past. The hardwood forests covering eastern North America were gradually cut or cleared during European settlement, with a resulting decline in the quantity and quality of forested habitat (2). In Canada, the destruction of huge expanses of timberland has severely limited suitable habitat for the red-shouldered hawk, and forest cutting and the filling in of wetlands has diminished the number of available prey. The breaking up of contiguous forest into small blocks of forest surrounded by other habitat has had the additional adverse affect of creating habitat more suitable to the larger and more aggressive great horned owl (Bubo virginianus) and red-tailed hawk (Buteo jamaicensis), which is the red-shouldered hawk’s closest competitor (10). 

Other threats to the red-shouldered hawk include pollution, accidental poisoning, and deliberate persecution from farmers who believe this bird threatens their poultry are also threats (2).

The red-shouldered hawk has not been the target of any known conservation efforts. However, recommended measures that are likely to benefit this species include planting hardwood trees in habitats where perches are limited, such as reclaimed surface mines. In addition, as this species is frequently found nesting near water, the preservation, maintenance or even construction of new water bodies would likely improve its nesting success (2).

Find out more about the red-shouldered hawk:

• Global Raptor Information Network - Red-shouldered hawk:
  http://www.globalraptors.org/grin/SpeciesResults.asp?specID=8188