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Sharp-shinned hawk

The Sharp-shinned hawk (Accipiter striatus) is the smallest accipiter in North America, a compact bird of prey measuring 9–14 inches (23–36 cm) in length with a wingspan of 17–22 inches (43–56 cm) and weighing 3–8 ounces (82–227 g), featuring short, rounded wings, a long square-tipped tail, and slender yellow legs adapted for agile flight through dense vegetation.^[1]^[2]^[3] Adults exhibit slate-gray upperparts, a rufous-barred underbelly, and a dark cap, while juveniles display brownish backs with heavy streaking below, enabling quick camouflage among branches during hunts.^[1]^[2]^[3] This species breeds across boreal and coniferous forests from Alaska and Canada southward to northern Mexico, favoring dense evergreen groves near clearings for nesting 20–60 feet (6–18 m) above ground in conifer trees.^[1]^[2]^[3] Highly migratory, sharp-shinned hawks undertake long-distance journeys, with northern populations wintering from the southern United States to Panama and northern South America, often concentrating at coastal and ridge watchpoints during fall passage from September to November.^[1]^[2] In winter, they adapt to a broader range of wooded edges, thickets, and even suburban areas with bird feeders, where they stealthily ambush prey.^[1]^[3] Their diet consists primarily of small songbirds (such as sparrows, warblers, and finches, comprising about 90% of intake), supplemented by rodents, insects, lizards, and occasionally bats, captured via surprise attacks in low, direct flights or from perches.^[1]^[2] Breeding occurs from May to August, with pairs constructing bulky nests of twigs lined with bark and greenery; females lay 3–6 eggs (typically 4–5), which are incubated for 30–35 days, and young fledge after 24–27 days, with males departing the nest earlier than females.^[1]^[2] Once threatened by pesticides like DDT in the mid-20th century, leading to population declines, sharp-shinned hawks have recovered and are currently classified as of least concern globally, though some regional monitoring sites report stable to slightly declining trends.^[1]^[3]

Taxonomy

Classification and Etymology

The Sharp-shinned hawk, scientifically named Accipiter striatus, was first described by French ornithologist Louis Jean Pierre Vieillot in 1808 in his work Histoire naturelle des oiseaux de l'Amérique septentrionale.^[4] It belongs to the genus Accipiter, which encompasses the true hawks, and the family Accipitridae, a diverse group that includes hawks, eagles, and kites. This classification reflects its characteristic short, rounded wings and long tail adapted for agile flight in forested environments, distinguishing it from other raptor families.^[5] The genus name Accipiter derives from the Latin word meaning "hawk" or "bird of prey," originating from the verb accipere, "to take" or "seize," alluding to the predatory nature of these birds.^[6] The specific epithet striatus comes from the Latin striatus, meaning "striped" or "furrowed," a reference to the distinctive dark bands on the bird's tail feathers.^[7] Taxonomic classification of the Sharp-shinned hawk has undergone debate, particularly regarding its species limits. A 2021 phylogenetic study using ultraconserved elements (UCEs) analyzed genetic and plumage data from Caribbean populations, recommending the recognition of four distinct species by elevating the three Caribbean subspecies (A. s. venator, A. s. striatus, and A. s. fringilloides) to full species status due to deep genetic divergence from mainland populations.^[8] However, this proposal has not been adopted by major authorities. The American Ornithological Society's 66th supplement to the Check-list of North American Birds (published August 2025) retained the single-species treatment for A. striatus while revising genus limits within Accipitridae based on molecular evidence; the Sharp-shinned hawk remains in Accipiter, but close relatives like the Cooper's hawk (Astur cooperii) were reclassified from Accipiter to the genus Astur due to phylogenetic analyses revealing they are not as closely related as previously assumed, despite superficial similarities in hunting behavior and morphology.^[9] The International Ornithological Congress (IOC) World Bird List version 14.2 (2025) has also not adopted any split, retaining the traditional single-species treatment.^[10]

Subspecies

The Sharp-shinned hawk (Accipiter striatus) comprises 10 recognized subspecies, categorized into three primary groups based on plumage, size, and geographic distribution: the nominate group (northern forms), the white-breasted group (Central and Andean populations), and the rufous-thighed group (southeastern South American forms), with additional insular variants in the Caribbean.^[11]^[12] These subspecies exhibit variations in size, coloration, and barring patterns adapted to local environments, though sexual dimorphism remains pronounced across all, with females generally larger than males. The nominate group, including A. s. velox (widespread in northern North America, with slate-blue upperparts and rufous barring below) and A. s. perobscurus (Haida Gwaii, Canada, slightly darker and larger), represents the migratory northern populations.^[13] The white-breasted group features paler underparts; A. s. chionogaster occurs in Central America from Mexico to Panama, while A. s. ventralis inhabits the Andes from Venezuela to northern Argentina. The rufous-thighed group, exemplified by A. s. erythronemius in southeastern South America, shows distinct rufous feathering on the thighs and underparts. Caribbean subspecies include A. s. venator (Puerto Rico, smaller at 28–33 cm with dark slate-gray upperparts and heavy rufous barring) and A. s. striatus (Hispaniola, blue-gray upperparts with finer barring). Other variants are A. s. fringilloides (Cuba), A. s. madrensis (Tres Marías Islands, Mexico), A. s. gaumeri (Yucatán Peninsula), and A. s. suttoni (southern Mexico to Honduras).^[14]^[13]

Subspecies	Geographic Range	Key Distinguishing Traits
A. s. velox	Alaska and Canada to northern Mexico	Slate-blue upperparts, rufous barring on underparts; highly migratory.^[15]
A. s. perobscurus	Haida Gwaii (Queen Charlotte Islands), Canada	Darker plumage, larger size compared to mainland nominate forms.^[11]
A. s. striatus	Hispaniola	Blue-gray upperparts, fine rufous barring; insular resident.^[16]
A. s. venator	Puerto Rico	Smaller (28–33 cm), dark slate-gray upperparts, heavy rufous underpart barring; endangered.^[14]
A. s. fringilloides	Cuba	Similar to Caribbean congeners but with slightly paler underparts.^[16]
A. s. madrensis	Tres Marías Islands, Mexico	Compact size, adapted to insular conditions.^[11]
A. s. gaumeri	Yucatán Peninsula, Mexico	Intermediate between northern and Central American forms in coloration.^[11]
A. s. suttoni	Southern Mexico to Honduras	Similar to gaumeri with intermediate coloration and size.^[11]
A. s. chionogaster	Mexico to Panama	White underparts with minimal barring; resident in humid forests.^[12]
A. s. ventralis	Andes (Venezuela to northern Argentina)	Pale white breast, adapted to high-elevation habitats.^[12]
A. s. erythronemius	Southeastern South America (e.g., Brazil, Argentina)	Rufous thighs and bold underpart barring; often considered distinct.^[12]

Taxonomic debate persists regarding the status of certain subspecies, particularly the Caribbean forms. A 2021 genetic study using ultraconserved elements analyzed mitochondrial and nuclear DNA, recommending the elevation of A. s. venator, A. s. striatus, and A. s. fringilloides to full species due to deep phylogenetic divergence from mainland populations; however, this proposal has not been adopted by major authorities like the American Ornithological Society or ITIS as of 2025.^[8] Hybridization with other Accipiter species, such as Cooper's hawk (A. cooperii), is documented but rare, typically occurring in overlapping ranges without significant gene flow.^[17]

Physical Characteristics

Size and Morphology

The Sharp-shinned hawk (Accipiter striatus) is North America's smallest accipiter, with a compact morphology adapted for high-speed, maneuverable flight through dense woodland environments. Adults typically measure 23–37 cm in length, have a wingspan of 43–56 cm, and weigh 82–219 g, making them roughly the size of a blue jay or slightly larger.^[18] The species exhibits pronounced reversed sexual dimorphism, with females averaging 25–30% larger than males; males are generally 23–27 cm long and 82–115 g, while females reach 29–37 cm and 150–219 g.^[18]^[1]^[15] This size disparity is characteristic of accipiters. Key morphological features include short, broad, and rounded wings that enhance agility for quick turns and bursts through vegetation, a long, square-tipped tail that aids in precise steering during pursuits, and a small, rounded head that minimizes air resistance.^[18]^[1] The legs are long and yellow with slender, pencil-thin appearance, complemented by long middle toes tipped with sharp talons suited for grasping and impaling small, mobile birds.^[19]^[20] The bill is small and strongly hooked, with a yellowish cere, facilitating the dispatch of songbird prey.^[21] Compared to other North American accipiters like the Cooper's hawk, the Sharp-shinned hawk is notably smaller overall, with proportionally shorter wings and a more delicate leg structure.^[18] Juveniles differ from adults primarily in plumage patterning, with streaked underparts versus the barred underparts of adults, though structural proportions remain similar across age classes.^[18] These traits collectively underscore the species' specialization as a stealthy woodland hunter.

Plumage and Coloration

The adult Sharp-shinned hawk exhibits distinctive plumage characterized by slate-blue to blue-gray upperparts, including the back, wings, and head, which often appear hooded due to the dark cap.^[18] Underparts are primarily white with fine, horizontal rufous to orange-red barring extending from the breast to the undertail coverts, while a pale supercilium contrasts with the darker eye line.^[2] The long, square-tipped tail features three to five narrow white bands alternating with broader dark gray bands, ending in a white tip.^[22] Juvenile Sharp-shinned hawks display a more cryptic plumage suited for woodland camouflage, with brownish upperparts marked by buffy fringes and streaks, contrasting sharply with the adult's gray tones.^[18] Underparts are buff to white with coarse, vertical brown streaking rather than barring, creating a heavily marked appearance on the breast and flanks.^[2] The tail mirrors the adult's pattern but with broader, more diffuse dark bands on a brownish base, and the eyes are yellow, darkening to orange and eventually red with age.^[22] Sexual differences in plumage are subtle; adult females tend to have slightly duller, more brownish-olive upperparts and coarser rufous barring on the underparts compared to the finer, brighter markings of males.^[22] Juveniles show minimal dimorphism beyond overall size, with both sexes sharing the streaked juvenile pattern. Plumage transitions occur through a preformative molt in the first year, replacing juvenile feathers with subadult-like patterns, followed by a definitive pre-basic molt annually after breeding, completing the shift to full adult plumage by the second calendar year.^[23] Females typically initiate molt earlier than males, with primaries replaced from innermost to outermost and tail feathers in a variable sequence.^[23] Subspecies exhibit minor plumage variations; for instance, the western A. s. ventralis is paler overall with reduced barring intensity, while the Mexican A. s. venator appears darker, particularly in juvenile stages with more saturated brown upperparts.^[24] For identification, Sharp-shinned hawks can be distinguished from similar Cooper's hawks by their smaller head that does not project beyond the wing wrists in flight, shorter and squarer tail lacking a rounded tip, and more rapid, crisp wingbeats creating a buoyant silhouette.^[18]^[2]

Geographic Range and Habitat

Distribution

The Sharp-shinned hawk (Accipiter striatus) occupies a broad geographic range across the Americas, spanning from the northern boreal forests to tropical regions. Its breeding distribution extends throughout much of North America, from western and central Alaska and northern Yukon Territory eastward to the Atlantic coast, and southward to southern California, Arizona, New Mexico, and central Mexico.^[13] Further south, breeding occurs in parts of Central America and into South America, reaching as far as northern Argentina, particularly in mountainous and eastern regions.^[20] The species comprises about 13 subspecies, with the nominate group (A. s. striatus) widespread across forested areas of Canada and the United States, extending breeding into northern South America.^[15]^[13] Populations in the northern portions of the range are largely migratory, with wintering grounds shifting southward to the southern United States, Central America, and northern South America, where individuals concentrate along major migratory corridors such as the East Coast and Gulf Coast of the U.S.^[19] Southern populations, including those in the tropics, are primarily resident year-round, maintaining presence in their breeding areas without significant seasonal movement.^[20] Subspecies distributions vary regionally; for example, A. s. velox occurs in western North America from Alaska through the western U.S., while A. s. perobscurus is restricted to Haida Gwaii (Queen Charlotte Islands) and adjacent coastal British Columbia.^[25] The subspecies A. s. venator is endemic to Puerto Rico.^[26] Vagrant records of the Sharp-shinned hawk are uncommon outside its typical American range, with rare sightings documented in Hawaii.^[27] Historically, the species experienced population declines due to pesticide use in the mid-20th century, but its breeding range has since expanded southward across the continent, with no major shifts reported as of 2025.^[20] This expansion follows recovery efforts and changes in land use, though the core distribution remains tied to forested landscapes.^[19]

Habitat Requirements

The Sharp-shinned hawk (Accipiter striatus) prefers dense coniferous or mixed forests for breeding, particularly in boreal regions where it selects sites adjacent to open areas or deciduous woodlands to facilitate foraging. These habitats provide the cover necessary for ambush hunting of small birds, with the species avoiding open grasslands, sparse woodlands, or purely deciduous forests lacking understory density. Foraging occurs primarily in woodland edges, second-growth thickets, and forest understories, where prey such as songbirds is abundant.^[28]^[1]^[13] This raptor occupies a broad altitudinal range, from sea level to near treeline, though nesting densities are highest in mid-elevation coniferous stands. In western North America, for example, nests have been documented from near sea level to over 2,000 meters in Oregon and 1,980–2,740 meters in Nevada.^[28]^[13]^[5] The species shuns alpine zones, open prairies, and barren deserts, favoring instead forested environments that offer structural complexity. Nesting occurs in tall coniferous trees such as pines, firs, or spruces, where platform nests constructed of sticks are placed 2.5–20 meters above the ground, often in the lower to mid-canopy for protection and access. These sites are typically in young, dense woodlands or forest patches with nearby clearings, ensuring proximity to foraging areas. During migration and winter, the hawk adapts to more varied edge habitats, including suburban woodlands and fragmented forests, demonstrating tolerance for moderate human-altered landscapes.^[29]^[28]^[12] Breeding takes place in cool boreal summers, while wintering shifts to milder tropical or subtropical regions, influencing habitat selection toward areas with persistent cover. Although sensitive to large-scale deforestation that fragments core breeding forests, the species persists in somewhat patchy or second-growth areas, particularly outside the breeding season.^[13]^[28]

Ecology and Behavior

Diet and Hunting

The Sharp-shinned hawk (Accipiter striatus) is a specialized avian predator, with songbirds constituting approximately 90% of its diet. Primary prey includes small passerines such as warblers, sparrows, finches, wrens, nuthatches, thrushes, and occasionally larger species like American robins or doves, typically weighing under 40 g but up to 80 g in routine captures.^[28] ^[30] The remaining 10% comprises small mammals (e.g., mice, voles, and occasionally squirrels or bats), reptiles (lizards, snakes), amphibians (frogs), and large insects (e.g., moths, grasshoppers).^[2] ^[1] This composition reflects its role as an opportunistic hunter in forested and woodland edges, where abundant small birds provide reliable foraging opportunities.^[15] Hunting strategies emphasize agility and stealth, adapted for dense vegetation. These hawks perch quietly in concealed spots within foliage or low branches (as low as 3 feet off the ground) and launch sudden, high-speed pursuits to surprise prey, often flying low and maneuvering through tight spaces with rapid wingbeats and glides in a characteristic "flap-flap-glide" pattern.^[28] ^[1] They employ "flush and pursue" tactics, startling birds into flight before chasing them, and may catch insects or larger prey mid-air during aerial dives.^[2] Talons secure the catch, after which the hawk typically plucks feathers on a stump, post, or branch before eating, avoiding open areas where stealth is compromised.^[28] ^[31] Their long tail and rounded wings aid precise navigation in cluttered habitats, while keen eyesight detects movement from perches.^[15] Daily food intake supports high metabolic demands, with adults consuming approximately 10–15% of their body weight daily, equivalent to roughly one small bird.^[32] ^[33] Sexual dimorphism influences foraging, as larger females (up to 328 g) target bigger prey (up to 300 g) than males (82-115 g, prey up to 100 g), allowing efficient energy acquisition for both.^[34] ^[30] Seasonal variations occur primarily in habitat use rather than diet composition; during winter, they shift to more open suburban areas and exploit bird feeders for concentrated songbird prey, while insects and non-avian items remain occasional supplements year-round.^[28] ^[2] Predation impacts on overall bird populations are minimal, as these hawks select vulnerable individuals without significantly affecting species abundance.^[28] Compared to the closely related Cooper's hawk (Accipiter cooperii), the Sharp-shinned hawk focuses on smaller, faster prey like sparrows and warblers in denser cover, pursuing them with bursty, acrobatic flights, whereas Cooper's hawks take a wider array of mid-sized birds and more mammals in somewhat opener settings.^[35] ^[36] This niche differentiation minimizes competition, with the Sharp-shinned's smaller size (10-14 inches long) enabling access to confined hunting zones.^[1]

Reproduction and Breeding

The Sharp-shinned hawk breeds primarily from late March to June across much of its North American range, aligning with the peak abundance of small songbird prey essential for provisioning nestlings. Pairs are typically monogamous during the breeding season and often return to the same nesting territory annually, with resident populations in southern regions defending these territories year-round to secure foraging and nesting resources.^[15]^[28]^[19] Courtship involves aerial displays where pairs circle high above the forest canopy while calling, with males performing steep dives and spreading their fluffy white undertail coverts to attract or impress the female; on the ground, both sexes engage in nest-scraping behaviors to select and prepare sites. Nests are bulky platforms of dead sticks, typically 1–2 feet in diameter and 4–6 inches deep, built anew or refurbished from old structures such as squirrel or crow nests, and lined with bark strips, twigs, or conifer needles; the female constructs most of the nest with material gathered by both sexes, placing it 10–60 feet above ground in dense conifer or mixed forest understory near the trunk of a tall tree.^[1]^[28]^[15] The female lays 4–5 pale bluish-white eggs, blotched with brown or reddish spots, at intervals of about one to two days, resulting in asynchronous hatching that promotes brood reduction; incubation lasts 30–35 days, performed mostly by the female while the male delivers prey to the nest, occasionally relieving her briefly. The altricial young hatch covered in white down with eyes closed, brooded continuously by the female for the first 1–2 weeks as the male supplies food, which she distributes to the chicks; nestlings develop rapidly, with eyes opening after about a week, and remain in the nest for 21–32 days before fledging, during which time sibling aggression is common, often leading to the death of the smallest chick due to starvation or attacks by larger siblings.^[28]^[1]^[15] Parents continue feeding the fledglings for up to 3–4 weeks post-fledging, with the female focusing on brooding and direct feeding early on while the male hunts; on average, 2–3 young fledge per successful nest, though productivity varies by habitat quality. Nesting success rates range from 50–78%, with higher rates in rural forests compared to urban edges, and pairs may renest if the first attempt fails early in the season, though typically only one brood is raised per year.^[1]^[37]^[38]

Migration and Movements

Northern populations of the Sharp-shinned hawk, particularly those in the nominate subspecies group (Accipiter striatus striatus), are long-distance migrants, traveling from breeding grounds across Alaska, Canada, and the northern United States to wintering areas in Central America and northern South America.^[28] Fall migration typically occurs from August to October, with birds departing breeding areas as early as late summer, while spring migration takes place from March to May, allowing return to northern breeding sites before nesting begins.^[1] These movements follow distinct routes, with eastern populations utilizing the Atlantic Flyway and funneling over the Appalachian Mountains, and western birds traversing the Rocky Mountains along the Central Flyway; hawk watches at sites like Cape May, New Jersey, and Hawk Mountain, Pennsylvania, record millions of individuals annually across North American monitoring stations, underscoring the scale of this migration. Migration distances can reach up to 6,000 km, with birds from the farthest northern breeding areas covering the longest journeys to reach wintering grounds in regions like Panama.^[1] Juveniles often disperse farther than adults during post-fledging movements and initial migrations, potentially exploring broader areas before settling on wintering sites, as evidenced by band recovery data showing hatch-year birds traveling greater distances on average. In contrast, resident populations in more southern or montane regions, such as parts of the tropics, exhibit local movements including altitudinal shifts in response to seasonal food availability or irruptive wanderings during periods of prey scarcity, rather than long-distance travel.^[28] Sharp-shinned hawks employ celestial and terrestrial cues for navigation, relying on stars for orientation during nocturnal flights and landmarks such as mountain ridges for diurnal guidance along migration corridors. Prior to departure, individuals accumulate significant fat reserves, with northern-origin birds showing higher fat levels—particularly females—to fuel the extended journeys, as measured through non-invasive estimation techniques during fall migration stopovers.^[39]

Conservation and Status

Population Dynamics

The global population of the Sharp-shinned hawk (Accipiter striatus) is estimated at approximately 1 million mature individuals, with the majority occurring across North and South America.^[28] In North America, breeding populations are estimated at around 410,000 mature individuals (Partners in Flight 2020), representing a significant portion of the species' total abundance.^[40] These estimates are derived from habitat suitability models and survey data, though the species' secretive nature and vast range make precise censuses challenging.^[5] Population trends for the Sharp-shinned hawk show a marked decline from the mid-1940s to the early 1970s, attributed to widespread eggshell thinning caused by DDT contamination, which reduced reproductive success across breeding ranges.^[19] Following the 1972 ban on DDT in the United States and similar restrictions elsewhere, populations rebounded substantially, with increases of 50-100% documented in North American surveys by the 1980s and 1990s.^[19] Long-term Breeding Bird Survey (BBS) data indicate overall increases since 1970, but recent trends (as of Partners in Flight 2024) show a slight decline over three generations in North America.^[40] High counts during fall migration, such as those at eastern watch sites, further support healthy flyway usage and population connectivity.^[2] Demographic parameters include annual adult survival rates influenced by factors such as predation, collisions, and environmental stressors, based on band recovery analyses across North American populations.^[41] Productivity averages 2.7 fledglings per breeding pair in mainland North America, with 91.7% of nests fledging at least one young, varying with prey availability.^[42] These rates contribute to a stable population equilibrium, as evidenced by long-term banding data showing consistent recruitment of young into breeding cohorts.^[43] Ongoing monitoring relies on standardized programs like the North American Breeding Bird Survey for breeding trends and the Christmas Bird Count for wintering abundance, which have documented range expansions and increased detections since the 1980s.^[40] Migration watch sites provide supplementary data on passage numbers, often exceeding 100,000 individuals annually at key bottlenecks, indicating robust connectivity between breeding and wintering grounds.^[44] Among subspecies, the northern populations (A. s. velox and others) remain stable and comprise the bulk of the global total, benefiting from extensive boreal forest habitats.^[12] In contrast, the Puerto Rican subspecies (A. s. venator) is critically limited, with recent surveys in 2025 detecting approximately 34 individuals across 10 active territories; historical estimates were around 150 in the 1990s, but the population fell to a low of about 19 following Hurricane Maria in 2017.^[45]

Threats and Management

The Sharp-shinned hawk faces several ongoing threats across its range, primarily habitat loss due to deforestation in tropical wintering grounds, which reduces available foraging and nesting areas in mature forests.^[46] Collisions with windows and buildings pose a significant risk during migration, as the species' low-altitude flight paths through urbanized areas lead to frequent fatalities, with studies identifying these as a leading cause of mortality.^[47] Legacy effects of pesticides like DDT continue to impact populations through bioaccumulation in prey, though levels have declined since bans, contributing to historical reproductive failures that persist regionally.^[48] Climate change exacerbates these issues by altering migration timing and breeding ranges, potentially decoupling prey availability and increasing vulnerability to storms in overwintering habitats.^[49] The subspecies Accipiter s. venator, endemic to Puerto Rico, is particularly vulnerable and listed as endangered under the U.S. Endangered Species Act since 1994, with threats intensified by habitat destruction from urbanization, agriculture, and infrastructure development, alongside predation by species like red-tailed hawks and pearly-eyed thrashers.^[50] Hurricanes, such as María in 2017, have decimated populations by causing up to 51% vegetation loss and reducing numbers to as few as 19 individuals, compounded by high nest failure rates (up to 69%) from parasites like bot flies.^[50] Globally, the Sharp-shinned hawk is assessed as Least Concern by the IUCN as of the latest evaluation, reflecting stable or recovering populations in many areas due to protective measures, though regional vulnerabilities persist in fragmented habitats.^[40] Conservation management emphasizes habitat protection through initiatives like the Neotropical Migratory Bird Conservation Act, which funds forest preservation in Latin America and the Caribbean to safeguard wintering sites for this and other migratory raptors.^[51] Efforts to reduce pesticide impacts include ongoing monitoring of contaminants in tissues, supporting regulatory bans that have aided recovery since the 1970s.^[52] Public education via hawk watch programs, such as those at Hawk Mountain Sanctuary, raises awareness of collision risks and promotes bird-friendly building designs to mitigate urban threats during migration.^[2] Recovery efforts for the Puerto Rican subspecies include captive rearing trials by The Peregrine Fund, involving egg collection, artificial incubation, and hand-rearing of chicks to boost fledging success through double-clutching and parasite treatments, with releases supplementing wild populations post-hurricanes; propagation efforts resumed in 2025 for the first time since prior to the 2017 hurricanes.^[53] Comprehensive monitoring programs, including annual breeding surveys and satellite tracking since 2015, track occupancy in montane forests and inform habitat restoration, though recovery criteria—such as 75% occupancy of suitable areas—remain unmet.^[50] These interventions, combined with protections under the Migratory Bird Treaty Act, aim to address both immediate risks and long-term resilience.

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Back, scapulars, rump, uppertail-coverts, and wing coverts muted grayish brown to brownish gray with most feathers having buffy, tan or true cinnamon (Smithe ...
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The sharp-shinned hawks laid in late May and June. ... Females of each species began molting first. Primaries were molted from the innermost outward in all ...
[25]
Systematics - Sharp-shinned Hawk - Accipiter striatus
Races chionogaster, ventralis and erythronemius often treated as three separate species: erythronemius (Rufous-thighed Hawk) of se. South America, chionogaster ...
[26]
SHARP-SHINNED HAWK - Birds of Nebraska – Online
May 23, 2018 · Three of the 10 subspecies listed by AviList (2025) have been considered full species (Ferguson-Lees and Christie 2005, Gill et al 2024) ...
[27]
[PDF] Puerto Rican Broad-Winged Hawk and Puerto Rican Sharp-Shinned ...
Extant breeding populations ofthe Puerto Rican sharp-shinned hawk are known from montane habitat of the Maricao Commonwealth Forest, Toro Negro Commonwealth ...
[28]
[PDF] Vol. 49, No. 1, 2018 - Western Birds Journal - Archive
The Hawaiian Islands bird checklist includes 338 species accepted through 2016. The Hawaii Bird Records Committee (HBRC) was formed in 2014 to provide a formal ...
[29]
Sharp-shinned Hawk Life History - All About Birds
A tiny hawk that appears in a blur of motion—and often disappears in a flurry of feathers. That's the Sharp-shinned Hawk, the smallest hawk in Canada and ...
[30]
Breeding - Sharp-shinned Hawk - Accipiter striatus - Birds of the World
35–60 cm wide, 10–20 cm deep, placed 2·5–20 m from ground; lined with bark and greenery. Uses many species of trees (see Habitat: breeding range, above), ...
[31]
Diet and Foraging - Sharp-shinned Hawk - Accipiter striatus
Most prey video are passerines weighing < 40 g, but routinely takes birds up to 80 g, e.g. American Robin (Turdus migratorius); on rare occasions, prey from 200 ...Missing: daily intake
[32]
Sharp-Shinned Hawk - Missouri Department of Conservation
Oct 9, 2024 · Sharp-shinned hawks are most abundant during the spring and fall when songbirds are migrating. They follow, migrating with their prey during the ...Missing: subspecies | Show results with:subspecies
[33]
Sharp-shinned hawks, stalkers of the bird world, use all their tricks to ...
Mar 2, 2024 · Ninety percent of a sharp-shinned hawk's diet is small birds ... Adult hawks need to eat four or five birds each day. For this reason ...Missing: intake body
[34]
All About Raptors - Diet & Eating Habits | United Parks & Resorts
For instance, the average female sharp-shinned hawk captures prey weighing up to 300 g (0.7 lb.), while the average male captures prey weighing up to 100 g (0.2 ...
[35]
Species Spotlight: Cooper's Hawk and Sharp-shinned Hawk
Mar 28, 2025 · Cooper's hawks (Accipiter cooperii) and sharp-shinned hawks (Accipiter striatus) are two closely related raptors that often cause confusion due to their ...
[36]
Sharp-shinned and Cooper's Hawks, the Uninvited Guests
Apr 16, 2018 · Both will prey heavily on birds. The Sharpie's diet is almost exclusively birds, while the Cooper's Hawks also prey on many mammals. Sharp- ...
[37]
[PDF] habitat use and productivity of sharp-shinned hawks nesting in an ...
Sharp-shinned Hawks nested in a range of forest types, from mature conifer plantations to young, almost purely deciduous stands, and this population.
[38]
[PDF] Nest-site selection by Sharp-shinned Hawks in Kentucky
In addition, as in my study, Sharp-shinned. Hawks in Missouri nested in high density stands of pine trees that averaged 16.7 m in height (Wiggers and Kritz 1991) ...
[39]
[PDF] Fat Stores of Migrant Sharp-shinned and Cooper's Hawks in New ...
, 1994-96) and fall (Manzano Mountains, 1992-96) migration in central New Mexico. SHARP-SHINNED HAWK ... migration distances (Kerlinger 1989), flight strategies.
[40]
Demography and Populations - Sharp-shinned Hawk - Accipiter ...
Productivity and nesting chronology of the Cooper's Hawk and Sharp-shinned Hawk in Missouri. ... success, including hatching rates, nest success, fledgling ...
[41]
Sharp-shinned Hawk Accipiter Striatus Species Factsheet | BirdLife ...
This species has a large, discontinuous range in the Americas. It occurs from Alaska (USA) and Canada south to Panama, and populations are also found in the ...
[42]
[PDF] Distribution, density, and productivity of accipiter hawks breeding in ...
Hatching success (number of eggs hatched/number of eggs laid) was lowest for Sharp-shinned Hawks (69.6%)) intermediate for Cooper's Hawks (74.0%)) and highest ...
[43]
Survival and causes of mortality in wintering Sharp-shinned Hawks ...
Aug 9, 2025 · ... Intraguild predation may help explain the observed disparity between sharp-shinned hawk activity and that of their prey. Predation risk ...
[44]
[PDF] Decreases in Migrating Sharp-shinned Hawks (accipiter Striatus) at ...
ASSTRACT.--Each fall, migrating Sharp-shinned Hawks (Accipiter striatus) are counted at traditional raptor-migration watch sites in eastern North America.<|control11|><|separator|>
[45]
The 2025 season is well underway with 34 individual Puerto Rican ...
Mar 15, 2025 · The 2025 season is well underway with 34 individual Puerto Rican Sharp-shinned Hawks (Gavilán de Sierra) observed and 10 active territories ...
[46]
Sharp-shinned Hawk | The Peregrine Fund
The Sharp-shinned Hawk is the smallest North American hawk, with a sharp ridge on its legs, dark gray back, reddish-orange breast bars, and long legs and tail.
[47]
Sharp-shinned Hawk - CT.gov
Conservation of large blocks of forested habitat will help provide suitable nesting areas for sharp-shinned hawks. The regulated use of pesticides will help ...
[48]
[PDF] Species Assessment for Sharp-shinned hawk - NY.Gov
In New York, the second Breeding Bird Atlas documented a 68% increase in occupancy of sharp-shinned hawks since the mid-1980s. Christmas Bird Count data in New ...Missing: subspecies | Show results with:subspecies
[49]
Shift to Later Timing by Autumnal Migrating Sharp-shinned Hawks
Mar 1, 2011 · Changes in environmental conditions could influence the survivorship of maladjusted individuals given potential decoupling between migration ...
[50]
[PDF] Puerto Rican Sharp-shinned Hawk (Accipiter striatus venator) 5 ...
Aug 11, 2023 · There has been recent genetic evidence that the Puerto Rican sharp-shinned hawk, along with two other endangered endemic Caribbean sharp-shinned ...
[51]
Neotropical Migratory Bird Conservation Act | U.S. Fish & Wildlife ...
The Neotropical Migratory Bird Conservation Act authorizes grants for the conservation of neotropical migratory birds in the United States, Canada, Latin ...Missing: Sharp- shinned hawk forest
[52]
[PDF] Environmental Contaminant Levels in Sharp-shinned Hawks from ...
ABSTRACT.--We examined contaminant levels in tissue samples of sharp-shinned hawks (Accipiter striatus) collected in the eastern U.S. from 1991-93.Missing: legacy | Show results with:legacy
[53]
Puerto Rico Program Captive Rearing and Release
The incubation period for a Puerto Rican Sharp-shinned Hawk is 32 days. Biologists weigh and candle the eggs every day to ensure that the embryos are developing ...