Accipiter striatus

Accipiter striatus: The Sharp-shinned Hawk

The sharp-shinned hawk, scientifically known as Accipiter striatus, is a small and agile raptor distributed across North America, Central America, South America, and the Greater Antilles. It is colloquially often nicknamed the "sharpie." Males are notably the smallest hawks found in the United States and Canada, though the species as a whole averages larger than some Neotropical species. The taxonomy of Accipiter striatus is complex and not fully resolved, with some authorities proposing that certain southern populations represent distinct species, such as the white-breasted hawk (A. chionogaster), plain-breasted hawk (A. ventralis), and rufous-thighed hawk (A. erythronemius).

Physical Characteristics and Behavior

Sharp-shinned hawks are characterized by their small size, short broad wings, and medium-length tails. Sexual dimorphism is pronounced, with females being significantly larger and heavier than males. Adult plumage varies among subspecies but typically features blue-grey upperparts and underparts barred with rufous or tawny colors. Juveniles exhibit dark brownish upperparts with rufous edging and streaked brown underparts. These hawks possess long, slender yellow legs and a hooked black bill. Their primary hunting method involves surprising and capturing prey, often small birds, by flying quickly through dense vegetation, a technique that requires considerable agility and can be hazardous.

Diet and Hunting

The diet of the sharp-shinned hawk consists predominantly of small birds, ranging from hummingbirds to larger species like the ruffed grouse. Males tend to target smaller avian prey, while females pursue larger birds, minimizing direct competition between the sexes. They are known to exploit backyard bird feeders to access abundant congregations of ideal prey. In addition to birds, they will occasionally prey on rodents, lizards, frogs, snakes, and large insects, with bats also recorded as prey. Their hunting prowess is particularly evident in their ability to navigate thickets swiftly.

Distribution and Habitat

This species is found in a wide array of woodland and forest types across its extensive range. The nominate group is widespread in North America, inhabiting forested areas and migrating south in winter. Other subspecies are found in highland regions from Mexico to the Andes and in tropical and subtropical areas of South America. They inhabit altitudes ranging from near sea level to over 4,000 meters, preferring coniferous forests, broad-leaved woodlands, and temperate or tropical highlands.

Reproduction

Sharp-shinned hawks build stick nests in large conifer or dense deciduous trees. Clutch sizes typically range from 4 to 5 eggs, though up to 8 have been recorded. The incubation period averages around 30 days. After hatching, the female broods the young for 16 to 23 days while the male defends the territory and provides food. The fledglings remain dependent on their parents for about four weeks after leaving the nest. Breeding behaviors are generally secretive, aimed at avoiding predation by larger raptors.

Conservation Status

Historically, sharp-shinned hawk populations declined significantly in the mid-20th century due to pesticide use, particularly DDT. However, populations in the United States and Canada have largely rebounded, potentially exceeding historical numbers, attributed to pesticide bans and the availability of prey from bird feeders. Despite this recovery, certain subspecies face conservation challenges. The Puerto Rican subspecies, Accipiter striatus venator, is listed as endangered. Other resident subspecies in the Greater Antilles are uncommon and decreasing, while the status of some southern subspecies like A. chionogaster is considered potentially problematic due to their limited ranges, though they remain fairly common locally. Other subspecies, such as A. ventralis and A. erythronemius, are considered fairly common and currently safe.