Sharp-shinned hawk
Sharp-shinned hawk | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Accipitriformes |
Family: | Accipitridae |
Genus: | Accipiter |
Species: | A. striatus
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Binomial name | |
Accipiter striatus Vieillot, 1808
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Subspecies | |
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Breeding Year-round Nonbreeding
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Synonyms | |
Accipiter velox |
The sharp-shinned hawk (Accipiter striatus) or northern sharp-shinned hawk, commonly known as a sharpie,[2] is a small hawk, with males being the smallest hawks in the United States and Canada, but with the species averaging larger than some Neotropical species, such as the tiny hawk. The taxonomy is far from resolved, with some authorities considering the southern taxa to represent three separate species: white-breasted hawk (A. chionogaster), plain-breasted hawk (A. ventralis), and rufous-thighed hawk (A. erythronemius).[3] The American Ornithological Society and some other checklists keeps all four variations conspecific.[4]
Taxonomy
The sharp-shinned hawk is sometimes separated into four species, with the northern group (see distribution) retaining both the
Storer (1952) suggested that the southernmost populations within the nominate group were paler below, thus approaching chionogaster. This has also been reflected in recent guides, where A. s. madrensis of southern Mexico is described as being relatively pale below (compared to more northern subspecies), but if this is a sign of intergradation with chionogaster or a north-south cline which includes both the members of the nominate group and chionogaster remains unclear. In Bolivia, ventralis and erythronemius approach each other, but no evidence of intergradation is known – something that, without actual specimens, also would be hard to prove due to the variability in the plumage of ventralis.
A 2021 of study of sharp-shinned hawks recommended recognising the three endemic Caribbean island subspecies as distinct species, based on analysis of nuclear and mitochondrial DNA and diagnosed by their plummage: A. striatus, restricted the island of Hispaniola, A. fringilloides to Cuba and A. venator to Puerto Rico. If this is accepted and A. striatus treated as endemic to Hispaniola, the continental complex would take the scientific name A. velox.[5]
Description
This section needs additional citations for verification. (April 2016) |
This is a small
- Nominate group: Cap dark and upperparts blue-grey (the former darker). Often, a few more-or-less random white spots can be seen on the scapulars (feathers attached to the wing that cover the meeting of wing and body). Underparts white with rufous or tawny bars. The crissum (the undertail coverts surrounding the cloaca) is white. Thighs rufous, but often barred white. The cheeks are tinged rufous (sometimes faint, but generally very distinct in taxa from the Greater Antilles). The irides are dark orange to red, but these are yellowish to pale orange in juveniles. 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.
- A. (s.) chionogaster (white-breasted hawk): Resembles the members of the nominate group, but upperparts darker (often appears almost black), thighs whitish-buff and underparts and cheeks entirely white. Juveniles have darker upperparts and distinctly finer streaking below than juveniles of the nominate group.
- A. (s.) ventralis (plain-breasted hawk): Polymorphic. The most common morph has dark grey upperparts (often appears almost black) and white underparts variably barred, shaded, or mottled with rufous or tawny-buff (extensively marked individuals may appear almost entirely rufous or tawny-buff below). Occasionally, the barring to the lower belly and flanks may appear duskier. The white morph has bluish-grey upperparts (similar to the nominate group), but its underparts are all white except for its rufous thighs. The rare dark morph, the only morph which sometimes lacks rufous thighs, is entirely sooty (occasionally with slight white barring to belly and faint grey bands in tail). The underparts of the females average paler than males of the same morph. The iris is typically yellow (contra illustrations in some books), but individuals (mainly sub-adults?) with a darker iris are occasionally seen. Juveniles have dark brownish or dusky upperparts with each feather typically edged rufous, giving a rather scaly appearance. The underparts are white streaked brown, and the thighs are rufous barred white. Occasionally, juveniles with underparts extensively rufous streaked blackish are seen.
- A. (s.) erythronemius (rufous-thighed hawk): Resembles the nominate group, but upperparts darker, streaking to underparts rufous or dusky, cheeks typically with a clear rufous patch (occasionally lacking almost entirely) and iris yellow (contra illustrations in some books). Juveniles resemble juveniles of the nominate group, but streaking to underparts typically restricted to throat and central underparts, with flanks scaled or barred (often also belly).
Distribution
This species is widespread in North America, Central America, South America and the Greater Antilles. Below, the distributions of the four groups (see taxonomy) are described as they occur roughly from north to south:
- The nominate (A. s. striatus) group is widespread in temperate parts of the US, Canada (in a few coastal regions), Mexico (highlands from Sonora to Oaxaca), Cuba, Hispaniola and Puerto Rico.
- A. (s.) chionogaster (white-breasted hawk) occurs in highlands from far southern Mexico (Chiapas and Oaxaca), through Honduras, Guatemala and El Salvador, to Nicaragua. It is, as far as known, resident, but some local movements may occur.
- A. (s.) ventralis (plain-breasted hawk) occurs in the coastal mountains of northern Venezuela and Colombia, south through the Andes from western Venezuela, through Colombia, Ecuador and Peru, to central Bolivia. A disjunct population occurs in the Tepuis of southern Venezuela (likely to extend into adjacent parts of Roraima in far northern Brazil, but this remains unconfirmed). It is, as far as known, resident, but some local movements may occur.
- A. (s.) erythronemius (rufous-thighed hawk) is widespread in eastern South America in eastern and southern Brazil, Uruguay, Paraguay, north-eastern Argentina and south-eastern Bolivia. It is, as far as known, resident in some regions and migratory in others. The movements are generally poorly understood, but it only occurs seasonally at some localities in Argentina.
Habitat
It occurs in a wide range of woodland and forest types, both dominated by
Behaviour
Diet
These birds 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. The great majority of this hawk's prey are small birds, especially various songbirds such as sparrows, wood-warblers, finches, wrens, nuthatches, tits, icterids and thrushes. Birds caught range in size from a 4.4 g (0.16 oz) Anna's hummingbird to a 577 g (1.272 lb) ruffed grouse and virtually any bird within this size range is potential prey. Typically, males will target smaller birds, such as sparrows and wood-warblers, and females will pursue larger prey, such as American robins and flickers, leading to a lack of conflict between the sexes for prey. These hawks often exploit 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. Rarely, sharp-shinned hawks will also eat rodents, lizards, frogs, snakes, and large insects, the latter typically being dragonflies captured on the wing during the hawk's migration. Bats have occasionally been recorded as a prey of this hawk.[8]
Reproduction
Sharp-shinned hawks construct a stick nest in a large conifer or dense group of deciduous trees. Clutches of 3 to 8 eggs have been recorded, but 4 to 5 eggs is the typical clutch size. The eggs measure 37.6 mm × 30 mm (1.48 in × 1.18 in) and weigh about 19 g (0.67 oz). The eggs are prized by egg-collectors, because they are heavily marked with surprisingly colorful and varied markings. The incubation period is thought to average at about 30 days. After hatching, the young 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 another four weeks. 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 American goshawk and the Cooper's hawk. While in migration, adults are sometimes preyed on by most of the bird-hunting, larger raptors, especially the peregrine falcon. The breeding behavior of the taxa chionogaster (white-breasted hawk), ventralis (plain-breasted hawk) and erythronemius (rufous-thighed hawk) are comparably poorly known, but based on the available knowledge they appear to differ little from that of the nominate group
Conservation
In North America this species declined in numbers in the 1960s and 1970s, probably as a result of the use of
References
- . Retrieved 11 November 2021.
- ^ https://birdfinding.info/sharp-shinned-hawk/
- ^ IOC World Bird List. 14.1. International Ornithological Congress. Retrieved 24 March 2024.
- ^ Lepage, Denis (ed.). "Sharp-shinned Hawk Accipiter striatus Vieillot, LJP 1808". Avibase. Retrieved 24 March 2024.
- .
- ISBN 0-618-12762-3
- ISBN 0-307-37002-X.
- .
- Dickinson, E. (2003). The Howard and Moore Complete Checklist of the Birds of the World. Christopher Helm. ISBN 0-7136-6536-X
- Ferguson-Lees, J., D. Christie, P. Burton, K. Franklin & D. Mead (2001). Raptors of the World. Christopher Helm. ISBN 0-7136-8026-1
- Hilty, S. (2002). Birds of Venezuela. Christopher Helm. ISBN 0-7136-6418-5
- Howell, S., & S. Webb (1995). A Guide to the Birds of Mexico and Northern Central America. Oxford University Press. ISBN 0-19-854012-4
- Sibley, D. (2000). North American Bird Guide. Pica Press. ISBN 1-873403-98-4
- Raffaele, H., J. Wiley, O. Garrido, A. Keith & J. Raffaeile (1998). Birds of the West Indies. Christopher Helm. ISBN 0-7136-4905-4
- Remsen, J. V., Jr., C. D. Cadena, A. Jaramillo, M. Nores, J. F. Pacheco, M. B. Robbins, T. S. Schulenberg, F. G. Stiles, D. F. Stotz, and K. J. Zimmer. Version 9 October 2007. A classification of the bird species of South America. American Ornithologists' Union.
- Restall, R., Clemencia Rodner & Miguel Lentino (2006). Birds of Northern South America vol. 1 & 2. Christopher Helm. ISBN 0-7136-7243-9(vol. 2).
- Sick, H. (1993). Birds in Brazil: A Natural History. Princeton University Press. ISBN 0-691-08569-2
- Storer, R. W. (1952). Variation in the resident Sharp-shinned Hawks of Mexico. Condor 54: 283-9.
External links
- Sharp-shinned Hawk Species Account – Cornell Lab of Ornithology
- Sharp-shinned Hawk - Accipiter striatus - USGS Patuxent Bird Identification InfoCenter
- Picture of Sharp-shinned Hawk (Juvenile male) in the hand at birdwatching-bliss.com
- Sharp-shinned Hawk Wing & Weight data at birdwatching-bliss.com
- Information and photos of Accipiter (striatus) chionogaster - Mayanbirding.
- Information and photo of Accipiter (striatus) chionogaster - the Peregrine Fund.
- Information and photo of Accipiter (striatus) erythronemius - the Peregrine Fund.
- Information and photo of Accipiter (striatus) ventralis - the Peregrine Fund.
- "Accipiter striatus". Integrated Taxonomic Information System. Retrieved 23 February 2009.
- "Sharp-shinned Hawk media". Internet Bird Collection.
- Sharp-shinned Hawk photo gallery at VIREO (Drexel University)
- Interactive range map of Accipiter striatus at IUCN Red List maps
Historical material
- "Falco pennsylvanicus, Slate-coloured Hawk", "Falco velox, Sharp-shinned Hawk"; in American Ornithology 2nd edition, volume 1 (1828) by Alexander Wilson and George Ord. Colour plate from 1st edition by A. Wilson.
- "Sharp-shinned or Slate-coloured Hawk, Falco fuscus Gmel." John James Audubon, Ornithological Biography volume 4 (1838). Illustration from Birds of America octavo edition, 1840.
- "American Brown or Slate-colored Hawk", Thomas Nuttall, A manual of the ornithology of the United States and of Canada; volume 1, The Land Birds (1832).