Sharp-Shinned Hawk Secrets: Unveiling the Diet and Deadly Hunting Habits of This Forest Predator

Introduction

The Sharp-shinned Hawk ( Accipiter striatus) is a small but fierce bird of prey found throughout North America, Central America, South America, and the Greater Antilles. Often referred to as "Sharpie" or "Little Blue Darter," this accipiter is a regular visitor to winter backyard bird feeders, not to feed on millet or sunflower but to prey on the attracted songbirds. Known for its agility and speed, the Sharp-shinned Hawk is a formidable predator, primarily targeting small birds. This article delves into the diet and hunting habits of the Sharp-shinned Hawk, exploring its preferred prey, hunting techniques, and adaptations that make it a successful hunter.

Identification and Appearance

The Sharp-shinned Hawk is the smallest hawk in the United States and Canada. Key identifiers include:

Size: The Sharp-shinned Hawk is the smallest hawk in North America (males). There is a considerable size difference between males and females, with females being significantly larger. This makes it the most sexually dimorphic of all North American raptors, with the smaller male only little larger than a Blue Jay, while the larger female is closer to the size of Common Grackle.
Wings and Tail: It has short, rounded wings and a long, square-tipped tail with an off-white terminal band. The tail is medium-length, banded in blackish and gray with the tip varying among individuals from slightly notched through the square to slightly rounded (often narrowly tipped white).
Coloration: Adult Sharp-shinned Hawks have blue-gray upperparts and rusty horizontal barring below. The head is small, appearing shorter in flight than the head of Cooper’s hawk, whose head projects noticeably past the leading edge of the wings; head color is the same as the nape and back. Immature birds have thick red-brown streaks below and are brown above with rusty fringes on the upperwing coverts, each feather-edged rufous, giving a rather scaly appearance.
Flight Pattern: Sharp-shinned hawks have a characteristic flap-and-glide flight pattern. In a glide, they appear compact with a small head that projects slightly past wrists. The body is short and “chesty.”
Legs and Bill: The legs are long and very slender (hence the common name) and yellow. The hooked bill is black and the cere is yellowish.

Distinguishing from Cooper's Hawk

It can be difficult to tell the sharp-shinned from the Cooper’s, however. The Sharp-shinned Hawk looks almost identical to another North American accipiter species, the Cooper's Hawk, and telling the difference between the two can be a challenge.

Size and Head Shape: Seen perched, the Sharp-shinned Hawk is the smaller of the two, with a rounded, proportionally smaller head that makes its eyes look extra-large. By contrast, a Cooper's Hawk has a rather blocky-looking, squarish head. In flight, a Sharpie's “wrists” are slightly pushed forward, and its small head barely extends past the leading edge of its wings, whereas a soaring Cooper's wings form a straight leading edge, and more of its larger head is visible.
Head Coloration: An adult Sharpie's dark head and nape form a continuous swath of color, while an adult Cooper's dark head is offset by a paler nape, making this species look as if it's wearing a cap.
Tail Shape: The Sharp-shinned Hawk's relatively shorter tail is square-tipped when folded, compared to the Cooper's more rounded tail, with outer feathers appearing shorter than the middle ones, apparent when the tail is folded as well as in flight.
Leg Size: The Sharp-shinned Hawk has thin, delicate-looking legs, while a Cooper's legs are thicker and sturdier-looking.

Habitat and Distribution

Widespread throughout North America, the Sharp-shinned Hawk may be found in wide variety of forest types from sea level to near alpine areas, as well as near rural, suburban and agricultural areas, where they often stalk bird feeders. Sharp-shinned Hawks winter primarily from the US-Canadian border to Central America. They are fairly common across most of the Lower 48 during migration, especially at raptor migration hotspots, but are rarely encountered during summer.

Habitat Preference: Sharp-shinned Hawks require dense forest, ideally with a closed canopy, for breeding. While favoring forests that contain conifers, they also nest in stands of aspen in Colorado, oak-hickory forest in Missouri, and the hardwood forests of the East.
Geographic Range: The Sharp-shinned Hawk also occurs in the Caribbean, Central America, and in South America, with a complex taxonomy to match. Ten subspecies are recognized, divided into three main subspecies groups: the Sharp-shinned Hawk (striatus group), White-breasted Hawk (chionogaster group), and Rufous-thighed Hawk (erythronemius group). Three species in the latter two groups (the Rufous-thighed Hawk, White-breasted Hawk, and Plain-breasted Hawk, all found in Central and South America) are sometimes recognized as separate species. One Caribbean subspecies, the Puerto Rican Sharp-shinned Hawk, is listed as Endangered under the Endangered Species Act.
Migration: The northernmost (striatus) group of Sharp-shinned Hawk is highly migratory, and the populations breeding in southern South America also may be migratory.

Diet and Hunting Behavior

Sharp-shinned Hawks are strictly carnivores with a diet primarily consisting of small birds. Songbirds (the size of an American robin and smaller) make up the bulk of the sharp-shinned hawk's diet.

Prey Selection: Songbirds make up about 90 percent of the Sharp-shinned Hawk’s diet. Birds the size of American Robins or smaller (especially warblers, sparrows, and thrushes) are the most frequent prey; bigger birds are at less risk, though they’re not completely safe. Studies report quail, shorebirds, doves, swifts, woodpeckers, and even falcons as prey. They will tackle birds up to the size of a Mourning Dove or Northern Bobwhite.
Opportunistic Predator: This small accipiter is an opportunistic predator, haunting bird feeders and other places its prey congregate, and snatching young birds from nests during the breeding season. Sharp-shinned hawks often visit backyard bird feeders in order to target congregations of ideal prey.
Hunting Techniques: The Sharp-shinned Hawk specializes in hunting small songbirds, which make up the majority of its diet. It hunts mostly by perching inside foliage and waiting for small birds to approach, or by approaching stealthily through dense cover, then bursting forth with incredibly swift flight to capture prey in its talons. Sometimes hunts by flying rapidly among the trees or low over the ground, threading its way around obstacles, taking prey by sudden surprise. It hunts by waiting inconspicuously on a hidden perch, then darting out to seize prey in a short burst of high-speed flight. It may also sneak up on prey during low-level flight. Its long legs and sharp talons allow it to reach into thick vegetation to nab prey, even mid-flight.
Versatile Hunter: Sharp-shinned Hawks are “pursuit hunters”, often surprising their prey on the wing by bursting out from a hidden perch with a rush of speed. They are versatile: small birds may be taken in the air or on the ground; they may pounce from perches as little as 3 feet above the ground to catch rodents; and they catch some insects on the wing.
Plucking Post: They often pluck the feathers off their prey on a post or other perch.

Breeding and Nesting Habits

Sharp-shinned hawks are monogamous and nest in solitary pairs. They usually breed between March and June.

Nest Construction: The birds construct a stick nest in a large conifer or dense group of deciduous trees. Nest site is very well concealed, usually in a dense conifer (such as spruce or fir) within forest or thick grove; usually 20-60' above ground, but can be lower or higher in suitably dense cover. Sometimes builds on top of old nest of squirrel or crow. 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. Both sexes bring nest material, female may do most of building.
Nest Placement: Throughout their range, Sharp-shinned Hawks favor conifer trees (pine, spruce, or fir) as nesting sites, but may also use aspens and hardwood trees. The nest is always placed under dense forest cover, usually toward the top of a tall tree, but well under the canopy. Most nests are anchored between horizontal limbs and the tree trunk. Nest sites may be reused each year - a pair will refurbish an old nest or build a new nest atop the old one.
Eggs: Usually 4-5, sometimes 3, rarely 1-6. Bluish-white fading to white, blotched and washed with brown. The eggs of Sharp-shinned hawks are prized by egg collectors because they are heavily marked with surprisingly colorful and varied markings.
Incubation and Chick Rearing: Incubation is mostly by female, 30-35 days. Male brings food to female on nest, and may sit on eggs while she is eating. Female remains near young for first 1-2 weeks after they hatch; male brings food, female feeds it to nestlings. 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. Young may move out of nest onto nearby branches after about 3-4 weeks, can fly at about 5-6 weeks. Parents continue to care for the fledglings for almost a month after they leave the nest.

Scrappy Nest Defenders: Sharp-shinned Hawks nest within the tree canopy in dense vegetation, so are difficult to observe while breeding. These scrappy little raptors are fiercely territorial and ably defend their nest from intruders.

Conservation Status

Sharp-shinned Hawk numbers have remained relatively stable between 1966 and 2019, according to the North American Breeding Bird Survey. 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. Partners in Flight estimates a global breeding population of 1 million and rates them 7 out of 20 on the Continental Concern Score, indicating a species of low conservation concern. However, the Puerto Rican Sharp-shinned Hawk is federally listed as Endangered and do not migrate.

Threats: Although the Sharp-shinned Hawk declined in the mid-20th century because of human persecution and the use of DDT, the species has largely recovered. Like other birds of prey, they suffered breeding failure when the pesticide DDT was in use in North America. Some carry high levels of this pesticide in their bodies even today, perhaps because much of their songbird prey spends winters in South America, where DDT is still used. Unfortunately, Sharp-shinned Hawks are still frequently victims of deadly collisions with glass and motor vehicles. Some populations may be vulnerable to continued pesticide use as well.
Conservation Actions: ABC's Pesticides program continues working to block or restrict dangerous pesticides, and we provide a number of online resources to help reduce glass collisions and fatalities, particularly at home windows. Living a bird-friendly life can have an immediate impact on migratory birds in the United States. Doing so can be as easy as adding native plants to your garden, avoiding pesticides, and keeping cats indoors.

Read also: Galapagos Hawk Feeding Habits

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