Henst's goshawk | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Accipitriformes |
Family: | Accipitridae |
Genus: | Astur |
Species: | A. henstii |
Binomial name | |
Astur henstii Schlegel, 1873 | |
Henst's goshawk (Astur henstii) is a species of bird of prey in the family Accipitridae. It is a large, diurnal bird endemic to the island of Madagascar. It is an obligate forest species that occurs at very low densities on the island and is rarely seen. It can only occupy the primary and secondary forests found within the island. Its natural habitats are subtropical or tropical dry forest, subtropical or tropical moist lowland forest, subtropical or tropical moist montane forest, and plantations.
It is threatened by habitat loss within Madagascar.
Henst's goshawk is a large forest raptor with a body length of 52 to 62 cm (20 to 24 in). The wingspan is between 86 and 100 cm (34 and 39 in). [2] [3] [4] There is a notable size discrepancy between males and females, with males weighing 609 g (1.343 lb) on average and the larger females weighing 960 to 1,140 g (2.12 to 2.51 lb) on average. It is one of the world's largest hawks, rivaling the Eurasian goshawk and Meyer's goshawk. [4] [5]
The body is mostly covered in a dark brownish-grey plumage that is quite indistinct while the underparts are lighter in colouration and have a barred pattern. [2] Juvenile colouration will vary and can be distinguished by having large brown spots on the breast and belly. [6] A strong distinguishing feature is a pale eye line on the contrasting dark head. The eyes and long legs of the species are yellow in colour.
In flight, Henst's goshawk will have its rounded wings and long, barred tail on display. Moreover, the pale coloured rump may be used to aid in identification of a flying individual. [2]
Henst's goshawk may be easily confused with an apparent mimic species also present in Madagascar, the Madagascar serpent eagle (Eutriorchis astur). [7] These species may be distinguished using a few key features. The first is size: Henst's goshawk is a much larger bird. The barred pattern present on the breast of Henst's goshawk is also more distinct than that of the Madagascar serpent eagle, which will have a more muted pattern with lighter coloration. [8]
Henst's goshawk is a species within the genus Astur . This group of birds mostly consists of goshawks and sparrowhawks. They lack a procoracoid foramen (a hole at the base of procoracoid bone). [9] This genus is within the family Accipitridae and order Accipitriformes which together make up the majority of the diurnal birds of prey.
The species was first described by Hermann Schlegel, a German ornithologist (who had a position at the Rijksmuseum van Natuurlijke Historie in Leiden, The Netherlands), in 1873.
There are two other Accipiter present on the island of Madagascar: Frances's sparrowhawk (Tachyspiza francesiae) and Madagascar sparrowhawk (Accipiter madagascariensis), both of which are smaller than Henst's goshawks. [8]
Henst's goshawk has a limited distribution within Madagascar due to specific habitat requirements. The preferred habitats of Henst's goshawk are primary rainforests and occasionally secondary woodland. Due to the physical geography of Madagascar these areas are restricted to the North, West and East of the island and do not occur within the southern portion. The southern portion of the island contains more arid and dry forests not suitable for raptor foraging. Consequently, the distribution of Henst's goshawk follows that of its preferred forest habitat and is not found in the southern portion of the island. [10] The primary forests of Madagascar may be categorized as dry deciduous and humid evergreen, both of which are occupied by Henst's goshawk.
It is known as an obligate forest species meaning it relies on forested habitat. This poses a problem, since these habitats are quickly being lost due to development in the region. However, it has been spotted within Eucalyptus plantations in the region. And may use these plantations to supplement for lost habitat.
Within this range, it is known to be a rare species that occurs at low densities, but present within all non-arid forests. The estimated range of occurrence is approximately 673000 km2. With a vertical range of occurrence ranging from sea level to 1800m above sea level. [1] As a top predator, large area requirements are necessary for foraging, explaining why the species occurs at low densities.
The goshawk will mainly hunt from a hidden perch within the forest and will rarely soar above the canopy cover. [6]
Henst's goshawk will form breeding pairs that are known as "socially monogamous". [11] Therefore, breeding pairs may seem like monogamous pairs but only do so for chick rearing, and will actively seek extra pair copulations on the side. Little is known about the courtship process of Henst's other than a "switchbacking" display observed by Safford and Duckworth. [12] These displays constitute hairpin turns and aerial displays followed by a distinct breeding vocalization. Following copulation, egg-laying takes place in October-November. A preference has been noted for nest sites to occur in high stature forests near a water course. [13]
Both adults take part in constructing large, bulky nests within the main fork of trees. [1] These nests may also be built within the aforementioned Eucalyptus plantations present on the island.The only observed clutch size has been 2 eggs with the measurements of 57.0 x 41.2 and 60.0 x 42.7 mm. [14]
Henst's appear to exhibit some sort of site fidelity, where the previous year's nest is re-used or another one is built only a couple of hundred meters away from the original. [15] Site fidelity is most likely explained by the specificity of preferred nest habitat to occur in old growth forests near water.
Although known as a climax predator within Madagascan rainforests, nest-predation has been observed within multiple Henst's goshawk populations. Following gestation, the female Goshawk will leave the nest unattended for long periods of time, while males only feed the chicks sporadically, leaving the nest vulnerable to predation events at the hands of Harrier-hawks, whereby chicks within unattended nests were quickly killed and consumed by a circling harrier-hawk on multiple occasions. [13]
Henst's goshawk is an adept forest predator whose diet mainly consists of medium to large sized birds and mammals. [11] With powerful eyesight, large curved talons and a curved raptor beak it is an extremely adept predatory animal. Hunting occurs from a discrete tree perch or from low forest floor flight. [15] Henst's goshawk will not leave the canopy cover while foraging.
The preferred prey are lemurs and poultry that occur within primary forest habitat. The ability to hunt lemurs makes Henst's goshawk an important part of the Madagascan food web. Henst's also does not exhibit a species preference and will hunt a large range of lemurs as well, ranging from 100g to 4kg. [2] Thereby Henst's plays an important role in maintaining population health in Lemurs by reducing the abundance of diseased and old individuals, keeping the population healthy.
The basic call is a loud, crackling and rapid "ang-ang-ang-ang...". [1] These vocalizations can be heard crackling through the canopy when in flight. However, these calls are rarely heard as Henst's is a more secretive species.
Except for the breeding season, when Henst's goshawk can be very loud and vocal. [15] They will utter a rapid succession of "keey-keey-keey' in order to communicate with potential breeding partners. [2]
An assessment by Birdlife International in 2016 has placed Henst's goshawk as Vulnerable on the IUCN Red List. [1] [16] The justification for this conservation status is the relatively small population size estimated at 1,000–2,250 individuals. With that population, the number of breeding adults is estimated to be 670-1,500 individuals. This population is estimated to be decreasing due to deforestation and human disturbance. [1]
The species is quite sparse and elusive to most surveys and therefore accurate population measures are difficult to obtain. A more thorough investigation of the population is declined and most likely will lead to a higher threat category.
Henst's goshawk occurs in several protected areas within Madagascar such as the Ranomafana National Park and the Tsingy de Bemaraha Strict Nature Reserve. [1] The Madagascan Government has pledged to further protect the island’s unique biodiversity.
The Accipitridae is one of the three families within the order Accipitriformes, and is a family of small to large birds of prey with strongly hooked bills and variable morphology based on diet. They feed on a range of prey items from insects to medium-sized mammals, with a number feeding on carrion and a few feeding on fruit. The Accipitridae have a cosmopolitan distribution, being found on all the world's continents and a number of oceanic island groups. Some species are migratory. The family contains 255 species which are divided into 70 genera.
Accipiter is a genus of birds of prey in the family Accipitridae. With around 50 recognized species it is the most diverse genus in its family. Most species are called goshawks or sparrowhawks, although with the exception of the American goshawk 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 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 shikra is a small bird of prey in the family Accipitridae found widely distributed in Asia and Africa where it is also called the little banded goshawk. The African forms may represent a separate species but have usually been considered as subspecies of the shikra. The shikra is very similar in appearance, as well as behavior, at least to some degree, to other species including the Chinese sparrowhawk, Eurasian goshawk and Eurasian sparrowhawk. They have a sharp two note call and have the typical flap and glide flight. Their calls are imitated by drongos and the common hawk-cuckoo resembles it in plumage. This species was formerly placed in the genus Accipiter.
The lizard buzzard, or lizard hawk, is a bird of prey in the family Accipitridae. It is native to Sub-Saharan Africa. Despite its name, it may be more closely related to the Accipiter hawks than the Buteo buzzards.
Frances's sparrowhawk is a small bird of prey. The nominate subspecies, A. f. francesiae, is endemic to Madagascar, and the other subspecies are found in the Comoro Islands. The Anjouan sparrowhawk, also known as the Anjouan Island sparrowhawk, Ndzuwani goshawk or Joanna Island goshawk, was thought to be extinct until searches in the 1980s and in 2005 confirmed that it is still extant.
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 Astur 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 semicollared hawk is a rare bird of prey species in the family Accipitridae. It is found in Colombia, Ecuador, Peru, and Venezuela. Its natural habitat is subtropical or tropical moist montane forests. It is potentially being affected by habitat loss.
The Madagascar sparrowhawk is a species of bird of prey in the family Accipitridae.
The black sparrowhawk, sometimes known as the black goshawk or great sparrowhawk, is the largest species of True hawk in Africa. It occurs mainly in forest and non-desert areas south of the Sahara, particularly where there are large trees suitable for nesting; favored habitat includes suburban and human-altered landscapes. It preys predominantly on birds of moderate size, such as pigeons and doves, in suburban areas.
The Ovambo or Ovampo sparrowhawk, also known as Hilgert's sparrowhawk, is a species of sub-Saharan African bird of prey in the family Accipitridae. It takes its name from the Ovamboland in northern Namibia.
The grey-bellied hawk or grey-bellied goshawk is a fairly large and rare species of forest-dwelling South American bird of prey in the family Accipitridae.
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 African goshawk is an African species of bird of prey in the genus Aerospiza. This species was formerly placed in the genus Accipiter.
The Chilean hawk is a bird of prey species belonging to the family Accipitridae. It breeds in Andes forests from central Chile and western Argentina south to Tierra del Fuego, from sea level to 2,700 m altitude. Some winter apparently in the lowlands of NW Argentina.
Zahamena National Park is a national park of Madagascar. Established in 1997, it covers an area of 423 square kilometres (163.32 sq mi) out of a total protected area of 643 square kilometres (248.26 sq mi). It is part of a UNESCO World Heritage Site, Rainforests of the Atsinanana, inscribed in 2007 and consisting of 13 specific areas located within eight national parks in the eastern part of Madagascar. In 2001, Bird Life International assessed avifauna of 112 species of which 67 species are exclusively endemic to Madagascar.
The Christmas goshawk or Christmas Island goshawk is a bird of prey in the goshawk and sparrowhawk family Accipitridae. It is a threatened endemic of Christmas Island, an Australian territory in the eastern Indian Ocean.
The Eurasian goshawk is a species of medium-large bird of prey in the family Accipitridae, a family which also includes other extant diurnal raptors, such as eagles, buzzards and harriers. It was formerly placed in the genus Accipiter. It is a widespread species that inhabits many of the temperate parts of the Eurasia. Except in a small portion of southern Asia, it is the only species of "goshawk" in its range and it is thus often referred to, both officially and unofficially, as simply the "goshawk". It is mainly resident, but birds from colder regions migrate south for the winter. As of 2023, the goshawks found primarily in North America are no longer considered Astur gentilis, but are now designated as the American goshawk.
The American goshawk is a species of raptor in the family Accipitridae. It was first described by Alexander Wilson in 1812. The American goshawk was previously considered conspecific with the Eurasian goshawk, but was assigned to a separate species in 2023 based on differences in morphology, vocalizations, and genetic divergence. It was formerly placed in the genus Accipiter. It is mainly resident, but birds from colder regions migrate south for the winter. In North America, migratory goshawks are often seen migrating south along mountain ridge tops at nearly any time of the fall depending on latitude.