Sharp-shinned hawks are small birds of prey native to the Americas. These acrobatic flyers have short broad wings and a medium-length tail banded in blackish and gray with the tip varying among individuals from slightly notched through the square to slightly rounded (often narrowly tipped white). The remiges (typically only visible in flight) are whitish barred blackish. The legs are long and very slender (hence the common name) and yellow. The hooked bill is black and the cere is yellowish. The upperparts are blue-grey (the former darker). Underparts are white with rufous or tawny bars. Juveniles have dark brownish upperparts, each feather edged rufous, giving a rather scaly appearance. The brown head is streaked whitish, and the whitish underparts are extensively streaked brown or reddish and usually with reddish barring on the sides.
Sharp-shinned hawks are widespread in North America, Central America, South America and the Greater Antilles. They live in a wide range of woodland and forest types, both dominated by conifers and by various types of broad-leaved trees (especially oaks). The largest populations are thought to occur in the temperate boreal forests, but winter in warmer regions farther south. Sharp-shinned hawks can also be found in shrublands, thickets, near suburban and agricultural areas.
Sharp-shinned hawks are secretive diurnal birds. They are generally solitary but may migrate in small groups. These are agile and acrobatic fliers that surprise and capture most of their prey from cover or while flying quickly through dense vegetation. They are adept at navigating dense thickets, although this hunting method is often hazardous to the hawk. Typically, males hunt smaller birds, such as sparrows and wood-warblers, and females pursue larger prey, such as American robins and flickers, leading to a lack of conflict between the sexes for prey. Sharp-shinned hawks often visit backyard bird feeders in order to target congregations of ideal prey. They often pluck the feathers off their prey on a post or other perch. After feeding, the birds spend their time resting as they need to digest their prey.
Sharp-shinned hawks are carnivores that feed on small birds, especially various songbirds such as sparrows, wood-warblers, finches, wrens, nuthatches, tits, icterids and thrushes. Rarely, they will also eat rodents, lizards, frogs, snakes, large insects, and occasionally bats.
Sharp-shinned hawks are monogamous and nest in solitary pairs. They usually breed between March and June. The birds construct a stick nest in a large conifer or dense group of deciduous trees. The nest is made with fresh twigs and lined with bark chips. The nesting sites and breeding behavior of Sharp-shinned hawks are generally secretive, in order to avoid the predation of larger raptors, such as the Northern goshawk and the Cooper's hawk. The female lays 3 to 8 eggs and incubates them within 30 days. The chicks are altricial; they hatch helpless and are covered with white down. They are brooded for 16 to 23 days by the female, while the male defends the territory and catches prey. The young fledge at the age of about a month and rely on their parents for feeding and protection for another 4 weeks. Reproductive maturity is usually reached at 2 years of age.
Sharp-shinned hawks are not considered threatened; however, these raptors are at risk from DDT and other pesticides, habitat loss and fragmentation, and are vulnerable to window strikes as they often hunt small birds and are common in suburban areas.
According to the Hawk Mountain Sanctuary resource, the total Sharp-shinned hawk population size is estimated to be over 1 million birds. According to the All About Birds resource, the total breeding population size of the species is 700,000 individuals. Overall, currently, Sharp-shinned hawks are classified as Least Concern (LC) on the IUCN Red List and their numbers today are increasing.
Due to their diet habits, Sharp-shinned hawks control small bird populations in their ecosystem. These small raptors are also an important food source for local predators such as Northern goshawk, Cooper's hawk, and Peregrine falcon.