Pygmy eagle

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Pygmy eagle
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Accipitriformes
Family: Accipitridae
Genus: Hieraaetus
Species:
H. weiskei
Binomial name
Hieraaetus weiskei
(Reichenow, 1900)
Hieraaetus morphnoides ssp weiskei distribution map.png
Synonyms

Hieraaetus morphnoides weiskei

The pygmy eagle or New Guinea hawk-eagle [2] (Hieraaetus weiskei) is a bird of prey found in New Guinea. Its natural habitats are primarily subtropical or tropical moist lowland forest and subtropical or tropical moist montane forest. It is the smallest species of eagle.

Contents

Taxonomy

The pygmy eagle was described by German naturalist Anton Reichenow as Eutolmaetus weiskei in 1900. It was subsequently considered a subspecies of the little eagle or a distinct species. Gjershaug and colleagues analysed it genetically and found it distinct enough to warrant species status. [2] [3] The International Ornithologists' Union (IOC) subsequently recognised it as a distinct species. [4] "Pygmy eagle" has been designated the official name by the IOC. [4]

Description

Size

The pygmy eagle is one of the world's smallest-known species of eagle and smallest living member of the Aquilinae subfamily, [2] only rivaled by the Great Nicobar serpent eagle in diminutive size by all modern species referred to as eagles. Pygmy eagle measures 38 to 48 cm (15 to 19 in) in length. The wingspan measures 112 to 126 cm (44 to 50 in). The female eagle is slightly larger than the male. One male pygmy eagle was found to weigh 483 g (1.065 lb). [5] [6] One study estimated the body mass of males of the species to fall around 406 g (0.895 lb) while that of females to fall around 555 g (1.224 lb). [7]

Identification

The pygmy eagle shares many characteristics with its counterpart the little eagle. The most notable differences are color. The pygmy eagle has darker more pronounced streaks on the nape, crown and ventral. The bird also shares characteristics with the booted eagle, both eagles have a unique underwing pattern. The plumage of the pygmy eagle can vary depending on the morph, light or dark. The dark morph is very similar to the dark morph of the little eagle, while the light morph shows the most differences that occur in the dark streaking. The dark morph seems to be rarer as 10 out of 11 field sightings have been the light morph. The feet of the eagle are described as grey or dull yellow. [8]

Voice

The voice of the pygmy eagle has been described as a "sip sip yeeee" during flights. The call can also be compared to the little eagle and booted eagle. The bird has also been observed giving a weaker single tone squeal. [8]

Distribution and habitat

The pygmy eagle primarily resides in lowland forests and forest edges in New Guinea. They enjoy nesting in closed forestry but have also been seen in open habitat and forest edges. The bird seems to be sparsely distributed throughout the hilly forests of New Guinea; however much of the forests of New Guinea are inaccessible so the eagle may be more abundant than it seems. One of the densely forested parts of New Guinea is Vogelkop or Bird's Head Peninsula. The pygmy eagle has been observed nineteen times in the Vogelkop over three years. It has also been observed on the island Buru and in the northern Moluccas. [8]

Food

Pygmy eagles have been seen soaring and diving on prey in forest canopies. The raptor is capable of very swift dives and attacks other avians such as the brown cuckoo-dove and mountain fruit-dove. Usually, the raptor low soars over the canopy scanning for prey and then dives on other birds in the canopy. [8]

Related Research Articles

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Eagle is the common name for many large birds of prey of the family Accipitridae. Eagles belong to several groups of genera, some of which are closely related. True eagles comprise the genus Aquila. Most of the 68 species of eagles are from Eurasia and Africa. Outside this area, just 14 species can be found—2 in North America, 9 in Central and South America, and 3 in Australia.

<span class="mw-page-title-main">Accipitridae</span> Family of birds of prey

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.

<span class="mw-page-title-main">Golden eagle</span> Species of eagle

The golden eagle is a bird of prey living in the Northern Hemisphere. It is the most widely distributed species of eagle. Like all eagles, it belongs to the family Accipitridae. They are one of the best-known birds of prey in the Northern Hemisphere. These birds are dark brown, with lighter golden-brown plumage on their napes. Immature eagles of this species typically have white on the tail and often have white markings on the wings. Golden eagles use their agility and speed combined with powerful feet and large, sharp talons to hunt a variety of prey, mainly hares, rabbits, and marmots and other ground squirrels. Golden eagles maintain home ranges or territories that may be as large as 200 km2 (77 sq mi). They build large nests in cliffs and other high places to which they may return for several breeding years. Most breeding activities take place in the spring; they are monogamous and may remain together for several years or possibly for life. Females lay up to four eggs, and then incubate them for six weeks. Typically, one or two young survive to fledge in about three months. These juvenile golden eagles usually attain full independence in the fall, after which they wander widely until establishing a territory for themselves in four to five years.

<span class="mw-page-title-main">Booted eagle</span> Species of bird

The booted eagle is a medium-sized mostly migratory bird of prey with a wide distribution in the Palearctic and southern Asia, wintering in the tropics of Africa and Asia, with a small, disjunct breeding population in south-western Africa. Like all eagles, it belongs to the family Accipitridae.

<span class="mw-page-title-main">Buteoninae</span> Subfamily of birds

The Buteoninae are a subfamily of birds of prey which consists of medium to large, broad-winged species.

<span class="mw-page-title-main">African hawk-eagle</span> Species of bird

The African hawk-eagle is a large bird of prey. Like all eagles, it belongs to the family Accipitridae. This species’ feathered legs mark it as a member of the Aquilinae subfamily. The African hawk-eagle breeds in tropical Sub-Saharan Africa. It is a bird of assorted woodland, including both savanna and hilly areas but the tend to occur in woodland that is typically dry. The species tends to be rare in areas where their preferred habitat type is absent. This species builds a stick nest of around 1 m (3.3 ft) across in a large tree. The clutch is generally one or two eggs. The African hawk-eagle is powerfully built and hunts small to medium sized mammals and birds predominantly, occasionally taking reptiles and other prey as well. The call is a shrill kluu-kluu-kluu. The African hawk-eagle is considered a fairly stable species and a species of Least Concern per the IUCN.

<span class="mw-page-title-main">Wahlberg's eagle</span> Species of bird

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<span class="mw-page-title-main">Changeable hawk-eagle</span> Crested hawk-eagle (Nisaetus cirrhatus) from South and Southeast Asia

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<span class="mw-page-title-main">Mountain hawk-eagle</span> Species of bird

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<span class="mw-page-title-main">Rufous-bellied eagle</span> Species of bird

The rufous-bellied eagle or rufous-bellied hawk-eagle is a bird of prey in the family Accipitridae that is found in the forested regions of tropical Asia. Relatively small for eagles and contrastingly patterned like a falcon, this species was earlier placed in the genus Hieraaetus and sometimes also in the genus Aquila but thought to be distinctive enough to belong to a separate genus.

<span class="mw-page-title-main">Bonelli's eagle</span> Large bird of prey

The Bonelli's eagle is a large bird of prey. The common name of the bird commemorates the Italian ornithologist and collector Franco Andrea Bonelli. Bonelli is credited with gathering the type specimen, most likely from an exploration of Sardinia. Some antiquated texts also refer to this species as the crestless hawk-eagle. Like all eagles, Bonelli's eagle belongs to the family Accipitridae. Its feathered legs marked it as member of the Aquilinae or booted eagle subfamily. This species breeds from Southern Europe, Africa on the montane perimeter of the Sahara Desert and across the Indian Subcontinent to Indonesia. In Eurasia, this species may be found as far west as Portugal and as far east as southeastern China and Thailand. It is usually a resident breeder. The Bonelli's eagle is often found in hilly or mountainous habitats, with rocky walls or crags, from sea level to 1,500 m (4,900 ft). Habitats are often open to wooded land and can occur in arid to semi-moist climate. This eagle, though it can be considered partially opportunistic, is something of a specialist predator of certain birds and mammals, especially rabbits, galliforms and pigeons. On evidence, when staple prey populations decline or are locally scarce, Bonelli's eagle switch to being an opportunistic predator of a wide variety of birds. Despite its persistence over a large range and its continued classification as a least concern species by the IUCN, the Bonelli's eagle has declined precipitously in various parts of its range, including almost all of its European distribution, and may face potential local extinction. The species' declines are due to widespread habitat destruction, electrocution from electricity pylons as well as persistent persecution.

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<i>Aquila</i> (bird) Genus of birds

Aquila is the genus of true eagles. The genus name is Latin for "eagle", possibly derived from aquilus, "dark in colour". It is often united with the sea eagles, buteos, and other more heavyset Accipitridae, but more recently they appear to be less distinct from the more slender accipitrine hawks than previously believed. Eagles are not a natural group, but denote essentially any bird of prey large enough to hunt sizeable vertebrate prey.

<span class="mw-page-title-main">Little eagle</span> One of the closest living relatives of the Haasts eagle, along with the booted eagle

The little eagle is a very small eagle native to Australia, measuring 45–55 cm in length and weighing 815 g (1.8 lb), roughly the size of a peregrine falcon. It tends to inhabit open woodland, grassland and arid regions, shunning dense forest. It is a near relative of both the Palearctic booted eagle and the massive but now extinct Haast's eagle of New Zealand.

<i>Hieraaetus</i> Genus of birds

The genus Hieraaetus, sometimes known as small eagles or hawk-eagles, denotes a group of smallish eagles usually placed in the accipitrid subfamilies Buteoninae or Aquilinae.

<span class="mw-page-title-main">Ayres's hawk-eagle</span> Species of bird

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<span class="mw-page-title-main">Barred hawk</span> Species of bird

The barred hawk is a species of bird of prey in the family Accipitridae. It has also been known as the black-chested hawk.

<span class="mw-page-title-main">Cassin's hawk-eagle</span> Species of bird

Cassin's hawk-eagle or Cassin's eagle, is a relatively small eagle in the family Accipitridae. Its feathered legs mark it as member of the Aquilinae or booted eagle subfamily. A forest-dependent species, it occurs in primary rainforests across western, central and (marginally) eastern Africa where it preys on birds and tree squirrels. It was named after John Cassin who first described it in 1865. Due to widespread habitat destruction, its populations are steadily declining but have not yet warranted upgrading its status from Least Concern.

<span class="mw-page-title-main">Aquilinae</span> Subfamily of birds

The Aquilinae are a subfamily of eagles of the family Accipitridae. The general common name used for members of this subfamily is "booted eagle", although this is also the common name of a member of the subfamily. At one point, this subfamily was considered inclusive with the Buteoninae based probably on some shared morphological characteristics. However, research on the DNA of the booted eagles has shown that they are a monophyletic group that probably have had millions of years of separation from other extant forms of accipitrid.

Booted eagles are eagles that have fully feathered tarsi. That is, their legs are covered with feathers down to the feet. Most other accipitrids have bare lower legs, scaled rather than feathered.

References

  1. BirdLife International (2016). "Hieraaetus weiskei". IUCN Red List of Threatened Species . 2016: e.T22734094A95074293. doi: 10.2305/IUCN.UK.2016-3.RLTS.T22734094A95074293.en . Retrieved 15 November 2021.
  2. 1 2 3 Gjershaug, Jan Ove; Lerner, Heather R.L.; Diserud, Ola H. (2009). "Taxonomy and distribution of the Pygmy Eagle Aquila (Hieraaetus) weiskei (Accipitriformes: Accipitridae)" (PDF). Zootaxa. 2326: 24–38. doi:10.11646/zootaxa.2326.1.2.
  3. "Hieraaetus weiskei". Avibase.
  4. 1 2 Gill, Frank; Donsker, David, eds. (2017). "New World vultures, Secretarybird, kites, hawks, eagles". World Bird List Version 8.1. International Ornithologists' Union. Retrieved 18 April 2018.
  5. "New Guinea Hawk Eagle – Aquila weiskei". The Eagle Directory. Retrieved 16 April 2018.
  6. del Hoyo, J., N. Collar, and J. S. Marks (2020). Pygmy Eagle (Hieraaetus weiskei), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA.
  7. Parry, S. J. (2001). The booted eagles (Aves: Accipitridae): perspectives in evolutionary biology. University of London, University College London (United Kingdom).
  8. 1 2 3 4 Debus, Stephen (August 2017). Australian Eagles and Eagle Like Birds (1 ed.). CSIRO Publishing. ISBN   9781486306930 . Retrieved 16 April 2018.