This article includes a list of general references, but it lacks sufficient corresponding inline citations .(September 2009) |
Plain-breasted hawk | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Accipitriformes |
Family: | Accipitridae |
Genus: | Accipiter |
Species: | A. ventralis |
Binomial name | |
Accipiter ventralis PL Sclater, 1866 | |
Synonyms | |
Accipiter striatus ventralis |
The plain-breasted hawk (Accipiter ventralis) is a small hawk described from Venezuela to western Bolivia. It is usually considered a subspecies of the sharp-shinned hawk by most taxonomists, including the American Ornithological Society, but 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).
The breeding range of the groups are entirely allopatric, although the wintering range of the nominate group partially overlaps with the range of chionogaster (as is also the case with certain taxa within the nominate group). This allopatry combined with differences in plumage (see appearance) and, apparently, certain measurements, has been the background for the split, but hard scientific data are presently lacking (AOU). Disregarding field guides, most material published in recent years (e.g. AOU, Ferguson-Lees et al. p. 586, and Dickinson et al.) has therefore considered all to be members of a single widespread species – but not without equivocation: Ferguson-Lees et al. say that if they were to make a world list, they would include the three taxa as separate species (p. 75), and the AOU's comment includes the note "split almost certainly good".
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.
This section needs additional citations for verification .(April 2016) |
This is a small Accipiter hawk, with males 23 to 30 cm (9.1 to 11.8 in) long, with a wingspan of 42 to 58 cm (17 to 23 in) and weight from 82–115 g (2.9–4.1 oz). As common in Accipiter hawks, females are distinctly larger in size, averaging some 30% longer, and with a weight advantage of more than 50% being common. The female measures 29 to 37 cm (11 to 15 in) in length, has a wingspan of 58 to 68 cm (23 to 27 in) and weighs 150 to 219 g (5.3 to 7.7 oz). The wings measure 14.1–22.9 cm (5.6–9.0 in) each, the tail is 12–19 cm (4.7–7.5 in) long and the tarsus is 4.5–5.9 cm (1.8–2.3 in). Measurements given here are for sharp-shinned hawk, but they are comparable for the remaining species. [1] Adults have short broad wings and a medium-length tail banded in blackish and gray with the tip varying among individuals from slightly notched through 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.
Birds can be 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 sharp-shinned hawk), 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.
It 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.
The plain-breasted hawk is found in upper tropical to temperate highlands; mainly at altitudes of 300–3,000 m (980–9,840 ft), but occasionally down to near sea-level and up to 4,000 m (13,000 ft).
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. Typically, males will target smaller birds, such as sparrows and wood-warblers, and females will pursue larger prey, such as thrushes 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.
Sharp-shinned hawks construct a stick nest. 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 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 breeding behavior of the plain-breasted hawk is comparably poorly known, but based on the available knowledge they appear to differ little from that of the sharp-shinned hawk.
The plain-breasted hawk is fairly common (but easily overlooked due to their secretive behavior) and presently considered safe.
The sharp-shinned hawk or northern sharp-shinned hawk, commonly known as a sharpie, 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, plain-breasted hawk, and rufous-thighed hawk. The American Ornithological Society keeps all four variations conspecific.
Accipiter is a genus of birds of prey in the family Accipitridae. With 49 recognized species it is the most diverse genus in its family. Most species are called goshawks or sparrowhawks, although almost all New World species are simply known as hawks. They can be anatomically distinguished from their relatives by the lack of a procoracoid foramen. Two small and aberrant species usually placed here do possess a large procoracoid foramen and are also distinct as regards DNA sequence. They may warrant separation in the old genus Hieraspiza.
The Accipitrinae are the subfamily of the Accipitridae often known as the "true" hawks, including all members of Accipiter and the closely related genera Microspizias, Erythrotriorchis, and Megatriorchis. The large and widespread genus Accipiter includes goshawks, sparrowhawks, the sharp-shinned hawk and others. They are primarily woodland birds that hunt by sudden dashes from a concealed perch, with long tails, broad wings and high visual acuity facilitating this lifestyle. In light of recent genetic research, the kites of the traditional subfamily Milvinae may also belong to this group.
The Levant sparrowhawk is a small bird of prey. It measures 32–38 cm (13–15 in) in length with a wingspan of 65–75 cm (26–30 in). The female is larger than the male, but the difference is not as marked as with Eurasian sparrowhawk. The adult male is blue-grey above, with dark wingtips, and barred reddish below.
The stripe-breasted spinetail is a passerine bird in the Furnariinae subfamily of the ovenbird family Furnariidae. It is found in Colombia, Trinidad, Tobago, and Venezuela.
The long-tailed hawk is an African bird of prey in the family Accipitridae. It is the only member of the genus Urotriorchis.
The pearl kite is a very small raptor found in open savanna habitat adjacent to deciduous woodland. It is the only member of the genus Gampsonyx. The scientific name commemorates the English naturalist William Swainson.
The savanna hawk is a large raptor found in open savanna and swamp edges. It was formerly placed in the genus Heterospizias. It breeds from Panama and Trinidad south to Bolivia, Uruguay and central Argentina. There are also reports of it in California, from 1973 in Alameda County and from 1974 in San Diego County.
The gray-headed kite is a raptor found in open woodland and swamp forests. It shares the genus Leptodon with the extremely rare white-collared kite. It breeds from eastern Mexico and Trinidad south to Peru, Bolivia, Brazil and northern Argentina.
The Malagasy kestrel, also known as the Madagascar kestrel, Malagasy spotted kestrel, Newton's kestrel, Madagascar spotted kestrel, katiti (Creole) or hitsikitsika (Malagasy), is a small bird of prey of the genus Falco. It is named after British ornithologist Edward Newton. It occurs in two subspecies on Madagascar and at Aldabra. The race from Aldabra is also called Aldabra kestrel. Its closest living relative is the Seychelles kestrel; they were at one time considered conspecific. Their common ancestors appear to have diverged very recently, probably less than 1 million years ago during the Early or Middle Pleistocene. The Mauritius kestrel is more distantly related.(Groombridge et al. 2002)
The tiny hawk is a small diurnal bird of prey found in or near forests, primarily humid, throughout much of the Neotropics. It is primarily a bird-eater, and is known to prey on hummingbirds.
The bicolored hawk is a species of bird of prey in the family Accipitridae. It is found in forest, woodland, second growth, plantations, and wooded savanna in southeastern Mexico, Central America, and northern and central South America. Though generally uncommon, it is the most common species of Accipiter in most of its range, but it does not occur at altitudes above 2,700 metres (8,900 ft) such as the highest parts of the Andes.
The chestnut-flanked sparrowhawk is a small west African species of sparrowhawk in the family Accipitridae.
The red-thighed sparrowhawk, alternatively known as the red-legged sparrowhawk or western little sparrowhawk, is a species of sparrowhawk in the family Accipitridae from western and northern central Africa.
The rufous-breasted sparrowhawk, also known as the rufous-chested sparrowhawk and as the red-breasted sparrowhawk, is a species of bird of prey in the family Accipitridae. It is found in Angola, Democratic Republic of the Congo, Eritrea, Eswatini, Ethiopia, Kenya, Lesotho, Malawi, Mozambique, Rwanda, South Africa, South Sudan, Tanzania, Uganda, Zambia, and Zimbabwe.
The Congo serpent eagle is a species of bird of prey in the family Accipitridae. It is the only member of the monotypic genus Dryotriorchis, although it was formerly placed in Circaetus. This species is distributed across the African tropical rainforest, including upper and lower Guinean forests. This serpent eagle specializes in hunting in these forests’ dark understories. It has two subspecies, the nominate subspecies Dryotriorchis spectabilis spectabilis and Dryotriorchis spectabilis batesi. Though monotypic, it appears to be very closely related to Circaetus. This hawk is a medium-sized bird with distinctive short, rounded wings and a long, rounded tail. It is varying shades of brown on its back and has a slight crest. Its breast is white with variable amounts of a rufous wash and, in the nominate subspecies, is covered in round, blackish spots. The subspecies D. s. batesi only has these dots on its flanks. The Congo serpent eagle closely resembles Cassin's hawk-eagle, and some ornithologists believe that this likeness is a rare example of avian mimicry. It is a very vocal raptor, and often is one of the most heard species in its habitat.
The double-toothed kite is a species of bird of prey in subfamily Accipitrinae, the "true" hawks, of family Accipitridae. It is found from central Mexico through Central America into much of northern and eastern South America.
The red-chested goshawk is a medium-size hawk of West Africa. It is often considered conspecific with the African goshawk.
The rufous-thighed hawk is a small hawk found from southern Brazil and southeastern Bolivia to Paraguay, Uruguay and northern Argentina. It is usually considered a subspecies of the sharp-shinned hawk by most taxonomists, including the American Ornithological Society, but the taxonomy is far from resolved, with some authorities considering the southern taxa to represent three separate species: white-breasted hawk, plain-breasted hawk, and rufous-thighed hawk.
The white-breasted hawk is a small hawk found from southern Mexico to Nicaragua. It is usually considered a subspecies of the sharp-shinned hawk by most taxonomists, including the American Ornithological Society, but the taxonomy is far from resolved, with some authorities considering the southern taxa to represent three separate species: white-breasted hawk, plain-breasted hawk, and rufous-thighed hawk.