Broad-winged buzzard

Broad-winged buzzard
	Broad-winged Buzzard (Adult, light morph)
Systematics
Class :	Birds (aves)
Order :	Birds of prey (Accipitriformes)
Family :	Hawk species (Accipitridae)
Subfamily :	Buzzard-like (buteoninae)
Genre :	Buzzards ( buteo )
Type :	Broad-winged buzzard
Scientific name
	Buteo platypterus
	( Vieillot , 1823)

The broad-winged buzzard ( Buteo platypterus ) is a small, but compact and robust looking bird of prey of the genus Buteo within the subfamily of the hawk-like (Accipitridae). It appears in a light color morph and a dark one. Dark morphous birds, whose plumage appears black-brown almost without drawing, are very rare. Although the broad-winged buzzard is a characteristic species of the Southeast Canadian and East American deciduous and mixed forests , little is known about the biology of the species that lives very hidden and secretly during the breeding season.

All broad-winged buzzards on the North American mainland are migratory birds with wintering areas from southern Florida to northern and north-central South America, south to central Bolivia . They move in large groups. Thousands of migrants can be seen at certain bottlenecks on their migration routes, especially on the move . The island ends are resident birds .

Platypterus example is primarily a lurking predators provided by well-camouflaged seat waiting spotted from prey and strikes the ground or in the air. Its prey range includes mammals up to the size of a rabbit , birds , reptiles , amphibians and large insects .

The species was first described by Louis Pierre Vieillot in 1823 . He called them the broad-winged passerine falcon ( Sparvius platypterus ). In 1901 Buteo platypterus became the valid name. In addition to the nominotypical taxon , which includes the mainland buzzards, 5 further subspecies are described, all of which are island endemic species.

According to the IUCN , the entire population of the species is not endangered (LC = Least Concern). Little data is available on the island endings, but their in and of itself small population numbers could be threatened primarily by habitat loss. From the on Puerto Rico -based subspecies p example. brunnescens are said to have lived only 124 individuals in 1994.

Appearance

The broad-winged buzzard is a small representative of the genus with a length of 34 - 44 centimeters. It is much smaller than the common buzzard , which is very common in Central Europe and which it resembles in many details of the color of the upper plumage. His body mass varies between 265 and 560 grams, depending on gender, time of year and nutritional status. Its size and weight are roughly the same as those of a rook . The sexes do not differ in color , but in terms of size and weight. Females of the nominate form are on average 8% larger and up to 17% heavier than males. The wingspan of large females reaches approximately 100 centimeters. The reverse size and weight dimorphism is significantly less pronounced in the island races. The species appears mainly in a light color morph . Dark morphic individuals are very rare; among migrating broad-winged buzzards, less than a per thousand were melanistic. In Alberta , in particular , black people seem to be a little more common. Intermediate stained individuals have not yet been described.

The broad-winged buzzard is drawn relatively characteristically and is also easy to identify due to its size. The sympatric red-shouldered buzzard is particularly likely to be mistaken for, but it is larger and longer-legged and is very well characterized by the reddish-brown color of the wing covers both on the upper and lower sides.

Light morph

Immaturer broad-winged buzzard (Helle Morphe)

Light variant of an adult individual

Juvenile broad-winged buzzard in flight. Characteristic are the gray edges of the wings, the imperfect lines of the under wing coverts and the gray subterminal tape

As with many species of the genus, the color of light morphous broad-winged buzzards is variable. Above all, the basic shade of the upper side plumage appears in different degrees of brightness, and the drawing of the breast and abdominal plumage varies in intensity and color from individual to individual. Typical specimens are piebald dark brown on the upper side and reddish brown spotted on the underside on a creamy white background.

The neck and parietal plumage often has white, or at least much lighter, feather shafts, so that it appears stringy white. Often a cream-colored over - eye stripe and a dark streak of malar are recognizable. The coat and back of the seated bird are usually uniformly dark brownish-gray. The lighter edges of most of the coverts and their black-brown inclusions are only recognizable up close in detail, but they determine the overall piebald impression. The rump and upper tail-coverts are conspicuously speckled dark reddish-brown on a cream-white background, the control feathers, which are banded in cream-colored on the upper side, are black. When the bird is sitting, only the broad central band is usually visible, when flying with spread control feathers two more. The wings are largely uniformly gray-brown on the upper side, with the coverts being a little darker than the dark-edged wings . The fingered, outer hand wings are darkest. The throat is white; it often has a distinctive, dark middle line or is dotted with black lines to varying degrees. The rest of the underside has a very variable intensity of rust-brown speckled or wavy on an almost pure white background, with the chest area being the most intensely colored, but the belly area often only showing a sparse rust-brown sparrow . The broad, curved wings are very light on the underside, almost white; the under wing-coverts are rusty brown or brown dashed or lined in several rows, the wings clearly bordered gray-black are finely linear, light gray. The outermost hand wings are almost half black. The black, finely white-ended control feathers of the slightly rounded tail have two complete pure white bands. The fluffy reddish-brown banded legs, which are feathered up to the intertarsial joint, are orange-yellow, the claws black. The beak is black or horn-colored bluish-black, at its base it is conspicuously surrounded by a yellow wax skin . The iris is cinnamon to chestnut brown.

Dark morph

Except for the tail, which resembles dark-colored, light-morphous individuals in its upper-side coloring, the entire upper side is dark, gloomy, brown-black. A few white strands can only appear in the neck plumage. The underside is also brown-black, almost without any drawings. In flight, the almost black under wing-coverts on the underside contrast sharply with the silver-colored, black-gray-edged wings. The underside of the tail is colored like that of light morphic buzzards, but the white parts are less bright.

Youth plumage

Juveniles are colored matt gray-brown on the upper side. The middle upper wing coverts often have whitish coloring elements, which in the seated bird can form an indicated band-shaped drawing element in this wing area. Neck and head are streaked brown and white. Usually a cream-colored stripe over the eyes is noticeable. The entire underside is dripped brown or drawn like a spearhead on a matt white background. The control feathers are the same color, but have a much lower contrast than the adults and are noticeably longer. The beak is gray-black, the legs are light yellow and the iris is initially light brown, later like the colored individuals.

In their body fletching juvenile, melanistic broad-winged buzzards hardly differ from adults. The rump and under-tail-coverts, however, are variably striped with maroon-brown and the underside coloring of the wings is similar to that of darker, light-morphous birds.

Mauser

The first complete moult in the juvenile plumage begins around 10 days when the hand and arm wings break through. At the age of 50 days, the juvenile plumage is fully developed. The first moult in the adult plumage occurs in the spring of next year. In about 14% of the birds this is a complete moult; these then appear in the adult plumage. The overwhelming majority molted to a large extent the wings and control springs but only different parts of the cover feathers and the body plumage; This moult is over in September at the latest. With them, characteristics of the juvenile plumage can still be recognized in the second autumn and winter. Broad-winged buzzards molt into their final adult plumage in the following spring. In females this moult begins during the breeding season, in males after it has finished. If it is not completed before the move, it will be interrupted during the move and locked in the winter quarters. Between these main moults, which are largely in conformity with the population, very different individual moults can take place.

Vocalizations

Broad-winged buzzards are happy to call throughout the year, but due to the predominant call characteristics they are not acoustically noticeable. It is characterized by a very light and fine, squeaky-looking, drawn-out call that is typically intoned twice. The second, elongated part is about half an octave lower than the intonation; it often ends with a songbird-like chirping. This call is adapted to the situation in many variations and seems to be largely the universal utterance of this type.

distribution

Breeding area

Distribution area of the broad-winged buzzard. Pink: breeding area (summer); greenish: wintering area; yellow: train corridor; Lines: directions of train

Except for the island endings in the Caribbean , the range of the species is in southern Canada and in the eastern and southeastern USA. Occurrences west of the Rocky Mountains do not exist and did not exist in earlier times.

The northwestern breeding areas are in the southernmost areas of the Canadian provinces of Yukon and northwestern territories . The species breeds very poorly in British Columbia ; to the east the brood distribution in Alberta , Saskatchewan and Manitoba becomes more closed and dense and continues to the Atlantic coast . The northern limit in Manitoba is around 50 ° north and rises to around 53 ° north on the Atlantic coast. Breeding areas are also found on Nova Scotia and Prince Edward Island . The broad-winged buzzard does not find suitable habitats along a strip on the Atlantic coast from Virginia south to Georgia . In Florida there are only some breeding occurrences in the extreme north.

From north to south, the western border of the breeding area in the United States is almost identical to the western borders of the states of Minnesota , Iowa , Missouri , Arkansas and Louisiana . In the north, the species is also found in northeastern North Dakota , in the central and southern United States in the eastern regions of Kansas , Oklahoma and Texas . An island of distribution that is largely isolated from other breeding occurrences exists between the states of Wyoming and South Dakota , and a smaller one in southeastern Alberta. In addition to this largely closed breeding area, individual broods are repeatedly found in suitable habitats further west.

In the Caribbean, Cuba is sparsely populated and Puerto Rico is very fragmented. The other occurrences can be found in the Systematics section. Hatching season observations from Hispaniola , Barbados and Trinidad have not yet been confirmed .

Wintering area

In the United States, there are wintering areas in southern Florida and southeastern Louisiana. In Mexico, the species winters on the Pacific coast between Colima and Oaxaca . With the exception of the Yucatán and a strip of the Pacific coast of Central America, the wintering areas from Chiapas to all of Central America south-east to Colombia , Venezuela and the Guiana States are wintering areas. The species was found southwards to the Pacific coast and its hinterland in large parts of Ecuador and Peru , as far as the east-central Bolivia. Overwinterers are regularly observed in the Brazilian states of Amazonas and Rondonia . Individual reports from Mato Grosso , Rio de Janeiro and Rio Grande do Sul indicate that the wintering areas in Brazil are more extensive than previously assumed.

habitat

Closed deciduous forests with interspersed clearings, like here in the Blue Ridge Mountains, are a preferred habitat of the species

The broad-winged buzzard is a type of deciduous or mixed forest with a largely closed canopy. There he lives in peripheral zones that border on open areas or forest areas in which clearings are interspersed. A clear preference for habitats near water can be seen throughout the habitat; slopes also seem to be preferred to flat areas. Areas that border on agricultural areas are not avoided entirely, but the species prefers undisturbed and largely unused areas. In the southern, rather dry breeding areas, B. platypterus also nests in woody trees that accompany rivers. The breeding habitats of the island races include evergreen mountain and secondary forests. It also colonizes different plantations and occasionally breeds in montane bush landscapes. In Puerto Rico, the species prefers to breed in moist, tree-lined karst areas that border on pastures or emerging secondary forests.

Even in winter, the species occurs exclusively in wooded, but at least bushy areas. Only when migrating does it appear in largely treeless ecosystems such as Llanos or Páramo . Observations come from evergreen tropical deciduous, foggy and rainforests interspersed with clearings or cleared areas, and occasionally from arid tree and bush communities. Overall, however, the overwintering habitats have only been insufficiently researched.

The broad-winged buzzard is primarily a type of lowland. In the Appalachian Mountains , however, there are many breeding sites in low mountain ranges up to about 1200 meters above sea level . In the wintering areas the species seems to prefer higher altitudes; From Central America and the eastern roofs of the Andes there are observations from 3000 - in individual cases even from 4000 meters above sea level.

Territoriality and space requirements

During the breeding season, the broad-winged buzzard establishes a territory that it defends more vigorously against the red-shouldered buzzard, red-tailed buzzard and the Hudson's harrier than against other birds of prey, which it only tries to drive away from the immediate vicinity of the nest. He attacks crows and other nest robbers emphatically, but is violently bullied by crows. There is only little data available on the space requirements. In Minnesota and Wisconsin , 320 acres have been recorded as the minimum sizes of breeding territories, but most habitats require much larger space, ranging from 2 km² in New York to 23.3 km² in Alberta. The smallest distance recorded so far between two flown nests was around 1.5 km.

The breeding territories of the island endings are significantly smaller. In Puerto Rico, the average size was only 82.5 acres.

migration

All mainland broad-winged buzzards leave their breeding territories in late summer and autumn and return in spring. The migration begins in the second decade of August and continues until the beginning of October. However, the vast majority leave the breeding area in the last two weeks of summer. In the draft funnel on the southern Texas Gulf coast , most migrants are counted in the last week of September and first week of October with daily peaks of more than 250,000 individuals. Broad-winged buzzards are broad-fronted migrants , which - depending on the geographical location of the breeding site - migrate to the southern sector. Broad-winged buzzards are regularly observed west of the Rocky Mountains and on the Pacific coast; but it is not known where these birds came from. Only a few migrants of the eastern populations choose a migration route via the Florida Keys and the Caribbean Islands to get to the South American wintering area. The first buzzards leave their wintering area in mid to late February. Moving home is less noticeable and does not lead to such pronounced concentration of movements as moving away. However, most of the spring migrants return to the USA at the South Texas bottleneck, where the migration peak is reached in the last week of March and the first week of April. The southernmost breeding populations did not occupy their breeding territory until mid-March at the earliest, the northwesternmost at the end of May at the latest.

Broad-winged buzzards are day migrants and especially thermal sailors. They migrate in very large groups, often with other buzzards, but especially with the prairie buzzard . The migration lasts around 40 days, during which those moving farthest southwards cover a distance of over 8,000 km. If the conditions are good, daily stages of around 400 km are possible. Usually the return home is completed faster than the departure.

Food and nutrition acquisition

The striped chipmunk is a common prey animal.

The broad-winged buzzard is a food generalist whose main diet is those prey that are most readily available. Therefore, long-term averages can differ greatly from regional and seasonal analyzes. Small mammals ( Northern short-tailed shrew , striped chipmunk , various bank voles , meadow vole ) and amphibians ( Anaxyrus americanicus and various frog species ) each make up around 35% of the ingested biomass . This is followed by birds in varying distribution , mainly nestlings of many different species, but also adults up to the size of a collar grouse , as well as reptiles, in the mainland populations mainly snakes, in the Caribbean subspecies mainly different types of lizards . B. platypterus regularly prey on insects , preferring large species such as beetles of the genera Phyllophaga and Harpalus , grasshoppers , dragonflies and large caterpillars . Insect food fluctuates very strongly with the seasons and is difficult to quantify. As nestling food, mammals and birds seem to make up a disproportionately high proportion of the biomass. As far as is known, the diet of the island endings is similar, but shifts in favor of reptiles (mostly lizards) and birds. With the exception of different species belonging to the respective wintering area, the composition of the food components in the winter half-year corresponds to that in the summer half-year.

The broad-winged buzzard is primarily a hide hunter . The vast majority of his daily campaign budget is taken up by this hunting method. From an elevated position (10-20 meters above the ground), usually a side branch near the top of the crown, he observes a relatively large area, well hidden. He beats mammals, reptiles and amphibians after an almost silent gliding flight on the ground and kills them with a neck bite. This hunting method seems to be successful very often. In a Missouri study, 67% of the attacks were successful. The majority of birds are beaten in flight or surprised in the nest. Pure flight hunting is seldom practiced (more often with swarming insects), and shaking was rarely observed.

Breeding biology

Broad-winged buzzards become sexually mature at one year old, and some (especially males) breed for the first time at this age. However, breeds of two yearlings are rare. The pair bond usually ends after the breeding season, but re-breeding of last year's partners has been observed. The species breeds once a year; only in the case of a very early clutch loss is there (rarely) a reduced second clutch. Pair formation and nest building begins immediately after arrival in the breeding area; Late February / early March on the Caribbean islands, in late March at the earliest in the southernmost breeding areas on the mainland, mid to late April in the Midwest, early May on the north east coast and late May in the northwestern Canadian breeding areas.

Pair formation, nest location and nest

In addition to the nest building itself, different, conspicuous show flights are part of the pair formation. Both partners circle over the nest location, often climbing to such great heights that they get out of sight. In the descent, the male, which usually flies higher, approaches the female until it almost comes into contact; afterwards both tip off and spiral downwards. This acrobatic flight is accompanied by frequent calls. The male handing over the food was also observed. With frequent copulations, mostly in the canopy of the trees, the male balances with half-opened wings on the female; at around a minute, they take a comparatively long time.

The nest is built close to, but not on the edge of, open areas; it is usually located in the first main fork of different deciduous or coniferous trees. American chestnut , yellow birch , American white oak and American quivering poplar , or Weymouth pine and American red pine are particularly popular . In Puerto Rico, the hibiscus Thespesia grandiflora is a common nest carrier. The average heights vary regionally and are between 8.2 and 14.8 meters; unusual nest heights were found with a minimum of one meter and a maximum of 27 meters.

Both partners build the nest, but the main work lies with the female. It's a compact, sturdy construction made of dead twigs picked from the ground and green, broken twigs. The outside is always clad with fresh conifer branches and the inside is padded with bits of bark, moss, lichen, bird feathers and animal or plant wool. Both the outer and inner lining are maintained and renewed during the entire breeding and nestling period. The nest is comparatively small: the average external dimensions were determined to be 30 to 53 centimeters (Caribbean: 18 to 79 centimeters); the height was between 12 and 30 centimeters. The brood bowl measured an average of 15-18 centimeters at a depth of 2 to 8 centimeters.

The reuse and renewal of an old species-specific nest occurs, as does the adaptation of the nests of other birds of prey or crows.

Clutch and young rearing

The clutch usually consists of 3 - 4 eggs on a matt, creamy white background, brown, sometimes lightly purple speckled eggs with an average size of 49 × 39 millimeters. The eggs of the island races are slightly smaller, while those of some subspecies are unspotted. The laying interval is 1 - 2 days, incubation begins after the first egg, and in large eggs after the second egg. It almost exclusively breeds the female; if the outside temperature is very hot (over 30 °), the eggs will not be incubated. Hatching occurs after 28-31 days. The chicks hatch with a thick, gray-white plumage and open eyes; in large clutches the difference in development between the first and last hatched can be considerable; Fratricide occurs but is very rare. The chicks are fed exclusively by the female, the male provides food for the young and the female. The chicks can sit at 8 days, from the 10th they start to stand in the nest. When they are able to break up smaller prey by themselves at around 15 days, the female also takes part in the hunt again. In the 5th - 6th week after hatching, the young birds leave the nest. At this time, the control springs and wings have not yet reached their final length, the flight skills are initially very limited. The fledgling fledglings stay close to the nest for the first two weeks after they leave the nest and occasionally return to the nest. Only then do they begin to hunt independently, but are usually looked after by the adult birds for another two weeks. No data are available on dismigration and breeding site loyalty.

Breeding success and life expectancy

Many broods fall victim to the Urson

The few studies on this parameter are small and not very informative. Smaller clutches tend to make at least one young fly more often than large clutches. In addition to bad weather and lack of food, the main reasons for complete brood losses are primarily predation by a large number of potential nest predators ( Urson , spruce martens , raccoons , American black bears , crows, owls , especially great horned owls ). In Puerto Rico, the red-tailed hawk is considered the main predator. In addition, the dangers of a very long train route, especially for first-time migrants, increase the risk of not surviving the first year of life. Recovered birds ringed when they were young had an average age of only 12 months. In the wild, a broad-winged buzzard that was ringed as an adult was found again after 14 years and 4 months.

Systematics

The first serious mention and illustration of the species was made in 1777 by John Frederick Miller . The bird shown, which Miller calls Falco fuscus , shows an immature buzzard, probably B. platypterus . Referring to Miller's illustration, Johann Friedrich Gmelin in 1788 and John Latham in 1790 mention this species. In 1812 Alexander Wilson describes a broad-winged buzzard that he himself collected near the Schuylkill River in Pennsylvania as Falco pennsylvanicus . Wilson could apparently no longer remember - already in very weak health - that he had already given this name to the corner-tailed cuckoo ( Accipiter striatus ). Although his friend and administrator George Ord noticed the double naming and he suggested F. lineatus instead of F. pennsylvanicus , this remained a nomen nudum , as Louis Pierre Vieillot had already described the hide in detail in 1823 and named it Sparvius platypterus . However, this taxon did not have a lasting effect on the naming of the species in the North American avifaunistic literature. Here Falco pennsylvanicus , F. latissimus , Buteo latissimus , but especially B. pennsylvanicus were used in different succession . The specific epithet platypterus introduced by Vieillot appears only rarely. In 1901, in the 10th amendment to the American Ornithological Society's checklist, the name Buteo platypterus ( Vieillot , 1823), which is still valid today, appears (as of late 2019). Both the German and the English trivial name correspond in content to the scientific epithet (Greek πλατυς, platus = broad, and Greek -πτερος, -pteros = -wing).

The family relationships of the species have not yet been fully clarified. It is believed that B. platypterus was pretty much at the beginning of Buteo's radiation . It is relatively isolated together with the two-banded buzzard and the red-shouldered buzzard, but also with some members of the genus Leucopternis in a clade . No sister species was found.

As of the end of 2019, six, largely clearly differentiated subspecies have been described, 5 of which are island endemics with a very limited distribution area and a low number of individuals.

B. p. brunnescens : adult and almost three-week nestling

Buteo platypterus platypterus ( Vieillot , 1823): description above. South-Central, Southwestern, and Southeastern Canada; and Eastern, East-Central, and Southeastern USA.
B. p. cubanensis Burns , 1911: Cuba . On average somewhat smaller than B. p. platypterus ; the crown feathers are brighter and broader red-brown edged; the banding of the lower legs is darker and thicker.
B. p. brunnescens Danforth & Smyth , 1935: Puerto Rico. Like B. p. cubanensis is clearly darker.
B. p. insulicola Riley , 1908: Antigua . Like the nominotypical taxon, it is somewhat paler and significantly smaller and lighter. Almost white, mostly unmarked throat, light stripes on chest and flanks.
B. p. rivierei H. Verrill , 1905: Dominica , Martinique and St. Lucia . Slightly darker than B. p. insulicola , with clearly dark dashed throat; according to B. p. insulicola the second smallest species.
B. p. antillarum Clark , 1905: St. Vincent , Grenadines , Grenada and Tobago . Greater than B. p. rivierei and a little brighter.

Persistence and Threat

The North American breeding area covers about 4.3 million km². Extensive reforestation campaigns, especially in the north-east of the USA, have increased the scope of potentially suitable habitats, and illegal shooting - one of the most important stock-limiting factors, especially in the late 19th and early 20th centuries - did not stop entirely, and is taking place in the USA and in Canada no longer a major role. As a predominantly forest species, this buzzard is less affected by collisions in road traffic and with wind turbines than species in open landscapes. For the migrating populations, however, the migration itself is associated with great dangers, above all because in many regions during the passage and in the winter quarters themselves, illegal shooting still represents a great risk potential. Global estimates of the total population are based on counts of migrating broad-winged buzzards. At observatories in the state of Veracruz on the Mexican Caribbean coast , an average of almost two million broad-winged buzzards were counted between 1994 and 2002. In the winter quarters, the increasing loss of habitat due to the conversion of forest areas into pastureland has a negative impact on the total population. Natural losses through illness, bad weather or predation do not play a role in relation to the population development. Serious quantitative assessments are lacking, but the total stock of mainland populations appears to be stable or even to increase slightly, apart from natural fluctuations caused primarily by the changing food supply. Accordingly, the IUCN assesses the entire population of B. platypterus as safe (LC = Least Concern).

Unfortunately, there is also a lack of reliable population figures for the island population. Due to the inherently small populations and the lack of alternatives, they are particularly sensitive to negative developments in their living space. Over a long period of time, forests on the Caribbean islands were cleared and converted into sugar cane plantations or pasture areas. This has drastically reduced the population of this species and that of other forest dwellers. Illegal shooting also contributed (and does) to the fact that the situation of the broad-winged buzzard is critical on some Caribbean islands. In an intensive review in 1994, only 124 individuals were counted on Puerto Rico, which were distributed over three breeding areas. How these populations have developed since then and what the situation is like on the other islands is unknown. In addition to the decline in illegal hunting, the crisis in the sugar cane industry could have a positive effect, as a result of which many former areas of cultivation are slowly being converted back into secondary forests .

literature

LJ Goodrich, ST Crocoll, SE Senner: Broad-winged Hawk (Buteo platypterus) . Version 2.0. (2019) In: AF Poole, FB Gill (Ed.): The Birds of North America . Cornell Lab of Ornithology, Ithaca, NY, USA 2014, doi: 10.2173 / bna.218 .
CM White, P. Boesman, JS Marks: Broad-winged Hawk (Buteo platypterus). In: J. del Hoyo, A. Elliott, J. Sargatal, DA Christie, E. de Juana (Eds.): Handbook of the Birds of the World Alive . Lynx Edicions, Barcelona 2019 (downloaded from https://www.hbw.com/node/53124 on November 25, 2019).
James Ferguson-Lees , David A. Christie : Raptors of the World . Houghton Mifflin, Boston 2001, ISBN 0-618-12762-3 .

Individual evidence

↑ LJ Goodrich, ST Crocoll, SE Senner: Broad-winged Hawk (Buteo platypterus) . Version 2.0. (2019) In: AF Poole, FB Gill (Ed.): The Birds of North America . Cornell Lab of Ornithology, Ithaca, NY, USA 2014. doi: 10.2173 / bna.218 - BNA ~ Introduction

↑ ^a ^b ^c ^d ^e ^f ^g ^h L. J. Goodrich, ST Crocoll, SE Senner: Broad-winged Hawk (Buteo platypterus). BNA ~ Distribution, Migration, and Habitat

↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ James Ferguson-Lees , David A. Christie : Raptors of the World . Houghton Mifflin, Boston 2001, ISBN 0-618-12762-3 , pp. 656–659 , plate 65 .

↑ ^a ^b ^c ^d L. J. Goodrich, ST Crocoll, SE Senner: Broad-winged Hawk (Buteo platypterus) . Version 2.0. (2019) - BNA ~ Diet an Foraging

↑ ^a ^b ^c Frank L. Burns: A Monograph of the Broad-Winged Hawk (Buteo platypterus). In: The Wilson Bulletin. Volume 23, Issue 3/4, 1911, pp. 143-320. (pdf engl.)

↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ C. M. White, P. Boesman, JS Marks: Broad-winged Hawk (Buteo platypterus). In: J. del Hoyo, A. Elliott, J. Sargatal, DA Christie, E. de Juana (Eds.): Handbook of the Birds of the World Alive . Lynx Edicions, Barcelona 2019 (downloaded from https://www.hbw.com/node/53124 on November 25, 2019).

↑ ^a ^b Buteo platypterus in the IUCN 2016-3 Red List of Threatened Species . Listed by: BirdLife International, 2016. Retrieved November 26, 2019.

↑ ^a ^b ^c L. J. Goodrich, ST Crocoll, SE Senner: Broad-winged Hawk (Buteo platypterus) - BNA ~ Appearance

^ BNA ~ Molt

↑ Voice example in Xeno-canto

↑ Dante Andres Meller, Glayson Ariel Bencke: First record of the Broad-winged Hawk Buteo platypterus in southern Brazil, with a compilation of published records for the country. In: Revista Brasileira de Ornitologia. Volume 20, No. 1, 2012, pp. 75-80. (pdf engl.)

↑ ^a ^b ^c ^d ^e ^f Francisco J. Vilella, Derek W. Hengstenberg: Broad-Winged Hawk (Buteo platypterus brunnescens) Movements and Habitat Use in a moist Limestone Forest of Puerto Rico. In: Ornithologia Neotropical. Volume 17, 2006, pp. 563-579. (pdf engl.)

^ BNA ~ Demography and Populations

↑ ^a ^b ^c ^d ^e ^f L. J. Goodrich, ST Crocoll, SE Senner: Broad-winged Hawk (Buteo platypterus) . Version 2.0. (2019) - Breeding

^ Carlos A. Delannoy, Adrianne G. Tossas: Breeding Biology and Nest Site Characteristics of Puerto Rican Broad-Winged Hawks at the Rio Abajo Forest. In: Caribbean Journal of Science. Volume 38, Volume 1-2, 2002, pp. 20-26. (pdf engl.)

↑ BNA-Demography and Populations

^ ^A ^b J. H. Riley: Notes on the Broad-Winged Hawks of the West Indies, with Description of a new Form. In: The Auk. Volume 25, 1908, pp. 268-276, p. 269.

^ Pierre Joseph Bonnaterre: Tableau encyclopédique et méthodique des trois régnes de la nature. Ornithology. Paris 1823. (BHL)

^ Tenth Supplement to the American Ornithologists' Union Check-List of North American Birds. In: The Auk. Volume 18, 1901, p. 299 (BHL)

↑ Birds and Words (birdsandwords.eu)

^ BNA systematics

↑ Heather RL Lerner, Matthew C. Klaver, David P. Mindell: Molecular Phylogenetics of the Buteonine Birds of Prey (Accipitridae). In: The Auk. Volume 125, Issue 2, 2008, pp. 304-315. doi: 10.1525 / auk.2008.06161

[BNA~Introduction-1] LJ Goodrich, ST Crocoll, SE Senner: Broad-winged Hawk (Buteo platypterus) . Version 2.0. (2019) In: AF Poole, FB Gill (Ed.): The Birds of North America . Cornell Lab of Ornithology, Ithaca, NY, USA 2014. doi: 10.2173 / bna.218 - BNA ~ Introduction

[BNA~Distribution,_Migration,_and_Habitat-2] ↑ ^a ^b ^c ^d ^e ^f ^g ^h L. J. Goodrich, ST Crocoll, SE Senner: Broad-winged Hawk (Buteo platypterus). BNA ~ Distribution, Migration, and Habitat

[Raptors-3] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ James Ferguson-Lees , David A. Christie : Raptors of the World . Houghton Mifflin, Boston 2001, ISBN 0-618-12762-3 , pp. 656–659 , plate 65 .

[BNA~Diet_an_Foraging-4] L. J. Goodrich, ST Crocoll, SE Senner: Broad-winged Hawk (Buteo platypterus) . Version 2.0. (2019) - BNA ~ Diet an Foraging

[Monograph-5] Frank L. Burns: A Monograph of the Broad-Winged Hawk (Buteo platypterus). In: The Wilson Bulletin. Volume 23, Issue 3/4, 1911, pp. 143-320. (pdf engl.)

[HBW-6] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ C. M. White, P. Boesman, JS Marks: Broad-winged Hawk (Buteo platypterus). In: J. del Hoyo, A. Elliott, J. Sargatal, DA Christie, E. de Juana (Eds.): Handbook of the Birds of the World Alive . Lynx Edicions, Barcelona 2019 (downloaded from https://www.hbw.com/node/53124 on November 25, 2019).