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Puerto Rican sharp-shinned hawk

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46-736: The Puerto Rican sharp-shinned hawk ( Accipiter striatus venator ), falcón de sierra or gavilán pecho rufo in Spanish, is an endemic subspecies of the North American sharp-shinned hawk , occurring only in Puerto Rico . Discovered in 1912 and described as a distinct sub-species, it has been placed on the United States Fish and Wildlife Service list of endangered species because of its rapidly dwindling population in Puerto Rico. It can be found in

92-638: 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 ( A. chionogaster ), plain-breasted hawk ( A. ventralis ), and rufous-thighed hawk ( A. erythronemius ). The American Ornithological Society and some other checklists keep all four species conspecific. The sharp-shinned hawk

138-491: 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

184-443: 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. The remaining plumage varies depending on group: This species

230-481: A result of the use of DDT and other pesticides . The population of USA and Canada has rebounded since and might even exceed historical numbers today, probably due to the combination of the ban on DDT and the proliferation of backyard bird feeders in North America which create unnaturally reliable and easy prey sources. Migratory sharp-shinned hawks are one of the most numerous raptors recorded at "hawk watches" across

276-403: 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 the northern group, but they are comparable for the remaining subspecies. Adults have short broad wings and

322-461: 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 study of sharp-shinned hawks recommended recognising

368-469: 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

414-420: Is approximately 150 birds. Human causes in population decline are from deforestation due to road construction, power lines, and communications facilities installations which have significantly reduced its habitat area. Natural disasters such as hurricanes also contribute significantly to population declines. Nest failures due to fledgling infestation with botfly larvae, warble fly larvae, and nest predation by

460-430: Is available on tanager breeding behavior. Males show off their brightest feathers to potential mates and rival males. Some species' courtship rituals involve bowing and tail lifting. Most tanagers build cup nests on branches in trees. Some nests are almost globular. Entrances are usually built on the side of the nest. The nests can be shallow or deep. The species of the tree in which they choose to build their nests and

506-523: Is found in tropical and subtropical regions; both in lowlands and highlands. 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

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552-419: Is potentially more problematic due to its limited range, although it, at least locally, remains fairly common. Tanagers Many: see text The tanagers (singular / ˈ t æ n ə dʒ ər / ) comprise the bird family Thraupidae , in the order Passeriformes . The family has a Neotropical distribution and is the second-largest family of birds. It represents about 4% of all avian species and 12% of

598-422: Is sometimes separated into four species, with the northern group ( see distribution ) retaining both the scientific name and the common name : sharp-shinned hawk ( A. striatus ). In addition to the nominate taxon ( A. s. striatus ), it includes the subspecies perobscurus , velox , suttoni , madrensis , fringilloides , and venator . The three remaining taxa, each considered a monotypic species if split, are

644-410: 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

690-566: 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: It occurs in a wide range of woodland and forest types, both dominated by conifers and by various types of broad-leaved trees (especially oaks ) The largest populations of the nominate group ( see taxonomy ) are thought to occur in

736-969: The Galápagos Islands and Cocos Island . Most of these species were formerly placed in the Emberizidae; the exceptions are the bananaquit that was placed in the Parulidae and the orangequit that was placed in the Thraupidae. These species build domed or covered nests with side entrances. They have evolved a variety of foraging techniques, including nectar-feeding ( Coereba , Euneornis ), seed-eating ( Geospiza , Loxigilla , Tiaris ), and insect gleaning ( Certhidea ). Darwin's finches : Most of these are lowland species. Many have ornamental features such as crests, and many have sexually dichromatic plumage. These species were formerly placed in Emberizidae. Some of these species were formerly placed in Emberizidae. This

782-572: The Neotropical birds. Traditionally, the family contained around 240 species of mostly brightly colored fruit-eating birds. As more of these birds were studied using modern molecular techniques, it became apparent that the traditional families were not monophyletic . Euphonia and Chlorophonia , which were once considered part of the tanager family, are now treated as members of the Fringillidae , in their own subfamily ( Euphoniinae ). Likewise,

828-494: The Peregrine Fund found only 19 sharp-shinneds on the island, and has launched a crisis fund campaign to solicit donations to help preserve the species. Puerto Rican sharp-shinned hawks select plantation and natural forest nest sites with similar vegetative structure and mountainous topography. Closed canopies and dense vegetation are sought by the hawks in the selection of nesting sites. They place their platform nests below

874-497: The Toro Negro State Forest . The Puerto Rican sharp-shinned hawk is a small forest hawk measuring approximately 28–33 cm (11–13 in). It has a dark blue/slate gray upper area with reddish-orange stripes on its breast. Immature birds have a brownish hue above and are striped below. It has broad wings and a proportionally long, squared-off tail, enabling it to turn and maneuver rapidly when chasing small birds through

920-932: The bill seems to be linked to the species' foraging habits. Tanagers are restricted to the Western Hemisphere and mainly to the tropics . About 60% of tanagers live in South America, and 30% of these species live in the Andes . Most species are endemic to a relatively small area. Most tanagers live in pairs or in small groups of three to five individuals. These groups may consist simply of parents and their offspring. These birds may also be seen in single-species or mixed flocks. Many tanagers are thought to have dull songs , though some are elaborate. Tanagers are omnivorous , and their diets vary by genus. They have been seen eating fruits , seeds , nectar , flower parts, and insects . Many pick insects off branches or from holes in

966-523: The forest canopy . The subspecies shows characteristics of sexual dimorphism , with the female almost 50% larger than the male. This allows each sex to focus their predatory efforts on different sized prey. The Puerto Rican sharp-shinned hawk feeds primarily on small birds ranging in size from tanagers to hummingbirds . It requires a home range of approximately 150 hectares (370 acres). Females lay two to three white eggs in March or April and incubate them while

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1012-510: The short-billed honeycreeper . The longest, the magpie tanager is 28 cm (11 in) and weighs 76 g (2.7 oz). The heaviest is the white-capped tanager , which weighs 114 g (4.02 oz) and measures about 24 cm (9.4 in). Both sexes are usually the same size and weight. Tanagers are often brightly colored, but some species are black and white. Males are typically more brightly colored than females and juveniles. Most tanagers have short, rounded wings. The shape of

1058-486: The temperate boreal forests , but winter in warmer regions farther south ( see distribution ). The taxa suttoni , madrensis (both from the nominate group), chionogaster (white-breasted hawk) and ventralis (plain-breasted hawk), are 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). The taxon erythronemius (rufous-thighed hawk)

1104-413: 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

1150-431: 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 In North America this species declined in numbers in the 1960s and 1970s, probably as

1196-513: The canopy on horizontal branches usually against the trunk or in crotches away from the trunk. Construction of nesting platforms usually begin in January after a breeding pair remain at their nesting sites permanently. Both males and females become more active in the nest building process one month before eggs are laid. Egg laying usually occurs during March and April and a second clutch may be laid rarely from May to July. Second clutches are only laid in

1242-691: The country. An exception is the subspecies from Puerto Rico , Accipiter striatus venator , which is rare and listed as endangered by the U.S. Fish & Wildlife Service . The remaining resident subspecies from the Greater Antilles, fringilliodes from Cuba and nominate ( A. s. striatus ) from Hispaniola, are uncommon, local, and, at least in the case of the latter, decreasing. Both ventralis (plain-breasted hawk) and erythronemius (rufous-thighed hawk) are fairly common (but easily overlooked due to their secretive behavior) and presently considered safe. The situation for chionogaster (white-breasted hawk)

1288-422: The event the first brood of eggs is lost. Typical incubation periods last for one month. Nesting period ends once the juveniles fly short distances from the nest and roost in trees 10 to 15 meters (32 to 48 ft) from the nest. More than half of fledging failures are caused by warble fly larvae. Most activity during early occupancy of nesting sites consisted of courtship displays and territorial flights. Both

1334-576: The family boundaries is that for many species their common names are no longer congruent with the families in which they are placed. As of July 2020 there are 39 species with "tanager" in the common name that are not placed in Thraupidae. These include the widely distributed scarlet tanager and western tanager which are both now placed in Cardinalidae . There are also 106 species within Thraupidae that have "finch" in their common name. A molecular phylogenetic study published in 2014 revealed that many of

1380-463: 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. 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

1426-531: The genera Piranga (which includes the scarlet tanager , summer tanager , and western tanager ), Chlorothraupis , and Habia appear to be members of the family Cardinalidae , and have been reassigned to that family by the American Ornithological Society . Tanagers are small to medium-sized birds. The shortest-bodied species, the white-eared conebill , is 9 cm (4 in) long and weighs 6 g (0.2 oz), barely smaller than

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1472-479: The larger size of the female, it is possible that some thrashers , 100 grams (3.5 ounces) are taken with some regularity. Sharp-shinned hawk A. s. chionogaster A. s. erythronemius A. s. fringilloides A. s. madrensis A. s. perobscurus A. s. striatus A. s. suttoni A. s. velox A. s. venator A. s. ventralis Accipiter velox The sharp-shinned hawk ( Accipiter striatus ) or northern sharp-shinned hawk , commonly known as

1518-521: 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

1564-409: The male searches for food. Average incubation period is approximately 32 days. Fledglings leave the nest 30 days after hatching. Restricted to five isolated mountain forest areas within the subtropical lower mountain wet forests and subtropical wet forest life zones of the main island of Puerto Rico, the subspecies has suffered a 40% decline in population since 1992. As of 1997, its estimated population

1610-420: The males and females partake in courtship displays which typically last from sunrise until mid-morning. In February, females stop foraging and remain near the nesting site. Only the female provides incubation and the role of the male is to provide all food to the female. The Puerto Rican sharp-shinned hawk's diet consists predominantly of small birds the size of tanagers , 30 grams (1.1 ounces) or smaller. Due to

1656-432: The nests' positions vary among genera. Most species nest in an area hidden by very dense vegetation. No information is yet known regarding the nests of some species. The clutch size is three to five eggs . The female incubates the eggs and builds the nest, but the male may feed the female while she incubates. Both sexes feed the young. Five species have helpers assist in feeding the young. These helpers are thought to be

1702-483: The pearly-eyed thrasher ( Margarops fuscatus ) have also contributed to its population reduction. Although an overall population of 129 birds has been reported on the island (Delannoy, 1992), in El Yunque National Forest , the only two sharp-shinned hawks sighted at that time were a solitary territorial pair that were sighted in the south-central part of the forest. After Hurricane Maria struck Puerto Rico,

1748-932: The previous year's nestlings. The family Thraupidae was introduced (as the subfamily Thraupinae) in 1847 by German ornithologist Jean Cabanis . The type genus is Thraupis . The family Thraupidae is a member of an assemblage of over 800 birds known as the New World, nine-primaried oscines . The traditional pre-molecular classification was largely based on the different feeding specializations. Nectar-feeders were placed in Coerebidae (honeycreepers), large-billed seed-eaters in Cardinalidae (cardinals and grosbeaks), smaller-billed seed-eaters in Emberizidae (New World finches and sparrows), ground-foraging insect-eaters in Icteridae (blackbirds) and fruit-eaters in Thraupidae. This classification

1794-411: The three endemic Caribbean island subspecies as distinct species, based on analysis of nuclear and mitochondrial DNA and diagnosed by their plumage: A. striatus , restricted to 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 . This

1840-488: The three taxa as separate species (p. 75), and the AOU's comment includes the note "split almost certainly good". 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

1886-431: The traditional genera were not monophyletic . In the resulting reorganization six new genera were introduced, eleven genera were resurrected and seven genera were abandoned. As of July 2023 the family contains 386 species which are divided into 15 subfamilies and 105 genera. For a complete list, see the article List of tanager species . The plushcap has no close relatives and is now placed in its own subfamily. It

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1932-520: The white-breasted hawk ( A. chionogaster ; Kaup , 1852), plain-breasted hawk ( A. ventralis ; Sclater , 1866) and rufous-thighed hawk ( A. erythronemius ; Kaup, 1850). The breeding ranges 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

1978-579: The wood. Other species look for insects on the undersides of leaves. Yet others wait on branches until they see a flying insect and catch it in the air. Many of these particular species inhabit the same areas, but these specializations alleviate competition. The breeding season is March through June in temperate areas and in September through October in South America . Some species are territorial, while others build their nests closer together. Little information

2024-455: Was formerly placed in the Cardinalidae; the other species were formerly placed in Emberizidae. These species are sexually dichromatic and many have yellow and black plumage. Except for Heterospingus they have slender bills. Sexually dichromatic species—males have blue plumage and females are green. Mainly arboreal with long tails and thick bills. Formerly placed in Cardinalidae . This subfamily includes Darwin's finches that are endemic to

2070-430: Was known to be problematic as analyses using other morphological characteristics often produced conflicting phylogenies. Beginning in the last decade of the 20th century, a series of molecular phylogenetic studies led to a complete reorganization of the tradition families. Thraupidae now includes large-billed seed eaters, thin-billed nectar feeders, foliage gleaners as well as fruit-eaters. One consequence of redefining

2116-616: Was previously placed either in the subfamily Catamblyrhynchinae within the Emberizidae or in its own family Catamblyrhynchidae. The coal-crested finch is endemic to the grasslands of Brazil and has no close relatives. It is unusual in that both sexes have a crest. It was formerly placed in Emberizidae. Two species with large thick bills. Parkerthraustes was formerly placed in Cardinalidae. Brightly colored sexually dichromatic birds, most form single-species flocks Grassland dwelling birds that were formerly placed in Emberizidae. Yellow billed birds: The blue finch ( Rhopospina caerulescens )

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