Very similar to Cooper’s Hawk in all plumages and often difficult to identify. The Sharp-shinned Hawk is a smaller, chunkier hawk and the Cooper’s Hawk often appears noticeably more slender and lanky, but this can be difficult to discern without extensive familiarity with both species. Further complicating factors, the sizes of large female Sharp-shinned Hawks and small male Cooper’s Hawks approach each other, making some intermediate-sized individuals particularly confusing. In flapping flight, Sharp-shinned Hawks generally have quicker, choppier wingstrokes than Cooper’s Hawks, and the wings of soaring/gliding Sharp-shinned Hawks are typically pushed slightly forward with the head hunched in the recess of the leading edge between the wrists. In contrast, the leading edge of the wings in Cooper’s Hawks is usually straighter with the head appearing to protrude noticeably.
The shape of the tail is the most commonly used feature to separate these two species of Accipiter. In the Sharp-shinned Hawk, the tail is slightly shorter and is noticeably squared at the tip (visible both when perched as well as in flight). In contrast, the Cooper’s Hawk has a relatively longer, more slender tail that is rounded at the tip, although individuals of both species that are missing some tail feathers can have confusing tail shapes. Other features used to separate these two species include the more distinct and contrasting dark crown of adult Cooper’s Hawks (more or less lacking in Sharp-shinned, which has a wholly gray crown that is the same colour as the upperparts) and the usually denser and heavier streaking and barring on the underparts of juvenile Sharp-shinned Hawks (juvenile Cooper’s Hawks typically have sparser, finer, and neater streaking on the whiter underparts, although some particularly pale juvenile Sharp-shinned Hawks can approach the appearance of typical juvenile Cooper's Hawks). Minor supporting field marks include the relatively larger eye that is more centrally-placed on the head and the thinner tarsus of Sharp-shinned Hawks.
| Most commonly heard call is a rapid, high-pitched, and thin kik-kik-kik-kik or kek-kek-kek-kek. This call is similar to a call given by the Cooper’s Hawk, but is noticeably higher-pitched and possibly faster. This call is given primarily during the breeding season and serves as communication between both members of a breeding pair. The male’s voice is slightly higher-pitched than that of the female. The male occasionally gives a single kip contact call when arriving at the nest which is often answered with a flatter, longer kep or keep call from the female. Perched birds also give a plaintive squealing call during courtship. During defense of the nest or pursuit of a predator, sometimes gives a ricky-ricky-ricky alarm call. Source: Bildstein and Meyer (2000). |
Courtship
Poorly known. Courtship displays often include both individuals of a pair soaring and circling above a nest site at sunrise, interspersing flapping flight with gliding flight, and occasionally partaking in exaggerated undulating flight with alternating shallow and steep dives followed by a recovery to original height. Both individuals call intermittently during these flight displays. This sunrise display is often accompanied by one individual of the pair tucking its wings and plummeting towards the ground, recovering only just above the canopy of the forest; this plummeting display typically ends the courtship display period, which last for 3-20 minutes.
Nest
Nests are notoriously difficult to detect due to the secretive nature of the species during the breeding season and dense, forested habitats that it chooses for nest sites. Nest building apparently begins shortly after arrival on the breeding grounds. Individuals commonly return to a nest site during subsequent years, but reuse of the actual nest is rare. The nest is a broad (60-65 cm across), flat (15 cm high), untidy structure that is composed of coniferous twigs and often lined with finer twigs and strips of bark. The nest is usually placed on a large limb and against the trunk, typically within a relatively dense area of foliage but well below the crown. The old nests of birds or squirrels are sometimes used as a base for the nest. It is most commonly placed in a conifer, even when most of the surrounding forest is composed of deciduous species, but deciduous trees are also chosen on occasion. Rarely, nests are placed in the hollow of a tree trunk or a cliff crevice. It is placed at a height of (2.4) 4-12 (19) m.
Eggs
Clutches of (3) 4-5 (8) eggs are laid between late May and early June and the incubation period is (30) 34-35 days. Both sexes incubate the eggs, and most eggs have usually hatched in B.C. by mid-July. The smooth, non-glossy eggs are dull white to pale bluish-white and are usually lightly and variably speckled with brown or purplish markings that are often concentrated towards the ends or middle of the egg. This species produces only one clutch per year.
Young
Following hatching, the young remain in the nest for 23-25 days (slightly longer for females). The nestlings are semi-altricial and downy, with short creamy-white or yellowish-white down when very young and pale purplish-buff to whitish down when slightly older, sometimes with some grey on the back. The nestlings are tended solely by the female, although the male brings food back to the nest for both the female and nestlings when they are very young. Dates for nestlings in B.C. range from early July to mid-August, but some nestlings may occur as early as late June. The young are able to fly at 23 days of age but are tended by the parents for 21-28 days after fledging.
Source: Campbell et al. (1990b); Baicich and Harrison (1997); Bildstein and Meyer (2000).
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The Sharp-shinned Hawk is a small hawk that relies primarily on avian prey, particularly small woodland-inhabiting or brush-inhabiting passerines such as warblers, sparrows, blackbirds, wrens, and thrushes. The range of avian prey consumed also includes such unlikely species as hummingbirds, grouse, shorebirds, and Marbled Murrelets, but none of these species are very important in the diet of this species anywhere in its range. It often concentrates around residential bird feeders as an easy source of prey. This species will also occasionally consume small mammals such as mice, voles, chipmunks, squirrels, and pocket gophers, as well as large insects such as moths. This species commonly hunts from concealed perches or during low flights, and relies on stealth, speed, and surprise to capture prey. In flight, it employs a series of quick, choppy wingbeats interspersed with short glides in a fashion that is typical of the genus Accipiter. Most pursuits are sudden and fast, and the hawk usually abandons the chase quickly if the prey is not captured.
Source: Bildstein and Meyer (2000).
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