| Revision as of 05:11, 30 May 2011 edit110.139.190.67 (talk) Filling in 5 references using Reflinks← Previous edit | Revision as of 06:18, 30 May 2011 edit undo110.139.190.67 (talk) refimproveTag: references removedNext edit → | ||
| Line 4: | Line 4: | ||
| | status_ref = <ref name="IUCNredlist" /> | | status_ref = <ref name="IUCNredlist" /> | ||
| | image = Haliaeetus albicilla -captive-8a.jpg | | image = Haliaeetus albicilla -captive-8a.jpg | ||
| | image_width = 300px | |||
| | image_caption = In captivity | | image_caption = In captivity | ||
| | regnum = ]ia | | regnum = ]ia | ||
| Line 16: | Line 15: | ||
| | binomial_authority = (], 1758) | | binomial_authority = (], 1758) | ||
| | range_map = Haliaeetus albicilla dis.PNG | | range_map = Haliaeetus albicilla dis.PNG | ||
| | range_map_width = 300px | |||
| | range_map_caption = Light Green: nesting area<br />Blue: wintering area<br />Dark Green: all-year | | range_map_caption = Light Green: nesting area<br />Blue: wintering area<br />Dark Green: all-year | ||
| | synonyms = | | synonyms = | ||
| Line 27: | Line 25: | ||
| == Description == | == Description == | ||
| The White-tailed Eagle is a large bird, 69–92 cm (27–36 in) long with a 182–244 cm (72–96 in) wingspan. Females, weighing 4–6.9 kg (8.8–15.2 lbs), are slightly larger than males, which weigh 3.1-5.4 kg (6.8–12 lbs).{{sfn|Ferguson-Lees|Christie|2001|p=}}{{page needed|date=May 2011}} It is the fourth largest eagle in the World.<ref name="Scotland. Scottish Natural Heritage 2009. p. 49">The Nature of Scotland. Scottish Natural Heritage. Spring 2009. p. 49.</ref> It has broad "barn door" wings, a large head and a thick "meat-cleaver" beak. The adult is mainly brown except for the paler head and neck, blackish flight feathers, distinctive white tail, and yellow bill and legs. In juvenile birds the tail and bill are darker, with the tail becoming white with a dark terminal band in sub-adults..{{sfn|Snow|Perrins|1998|p=}}{{page needed|date=May 2011}} | The White-tailed Eagle is a large bird, 69–92 cm (27–36 in) long with a 182–244 cm (72–96 in) wingspan. Females, weighing 4–6.9 kg (8.8–15.2 lbs), are slightly larger than males, which weigh 3.1-5.4 kg (6.8–12 lbs).{{sfn|Ferguson-Lees|Christie|2001|p=}}{{page needed|date=May 2011}} It is the fourth largest eagle in the World.<ref name="Scotland. Scottish Natural Heritage 2009. p. 49">The Nature of Scotland. Scottish Natural Heritage. Spring 2009. p. 49.</ref> It has broad "barn door" wings, a large head and a thick "meat-cleaver" beak. The adult is mainly brown except for the paler head and neck, blackish flight feathers, distinctive white tail, and yellow bill and legs. In juvenile birds the tail and bill are darker, with the tail becoming white with a dark terminal band in sub-adults..{{sfn|Snow|Perrins|1998|p=}}{{page needed|date=May 2011}} | ||
| Some individuals have been found to live over 25 years,<ref>{{cite web|url=http://www.mtv3.fi/uutiset/kotimaa.shtml/arkistot/kotimaa/2008/07/671963 |title=Merikotkien määrä lisääntyy |publisher=MTV3.fi |date= |accessdate=2011-05-30}}</ref> 21 years on average.<ref name="Scotland. Scottish Natural Heritage 2009. p. 49" /> | Some individuals have been found to live over 25 years,<ref>{{cite web | url = http://www.mtv3.fi/uutiset/kotimaa.shtml/arkistot/kotimaa/2008/07/671963 | title = Merikotkien määrä lisääntyy | publisher = MTV3.fi | date = | accessdate = 2011-05-30 }}</ref> 21 years on average.<ref name="Scotland. Scottish Natural Heritage 2009. p. 49" /> | ||
| ==Distribution and systematics== | == Distribution and systematics == | ||
| ] warning its young to hide (which it did).]] | ] warning its young to hide (which it did).]] | ||
| ]]] | ]]] | ||
| ] | ] | ||
| This large ] breeds in northern ] and northern ]. The largest population in Europe is found along the coast of ]. The World population in 2008 stands at only 9,000 - 11,000 pairs.<ref name="Scotland. Scottish Natural Heritage 2009. p. 49" /> They are mostly resident, only the northernmost birds such as the eastern ]n and ]n population ] south in winter. | This large ] breeds in northern ] and northern ]. The largest population in Europe is found along the coast of ]. The World population in 2008 stands at only 9,000 - 11,000 pairs.<ref name="Scotland. Scottish Natural Heritage 2009. p. 49" /> They are mostly resident, only the northernmost birds such as the eastern ]n and ]n population ] south in winter. | ||
| Small disjunct resident populations occur in southwesternmost ] and western ]. The former has been proposed as a distinct ] ''groenlandicus'' based on their very large size and body proportions. However, the species is now considered ] and the size variation is ] according to ].{{sfn|del Hoyo|Elliott|Sargatal|1994|p=}}{{page needed|date=May 2011}} A recent genetic study of ] |
Small disjunct resident populations occur in southwesternmost ] and western ]. The former has been proposed as a distinct ] ''groenlandicus'' based on their very large size and body proportions. However, the species is now considered ] and the size variation is ] according to ].{{sfn|del Hoyo|Elliott|Sargatal|1994|p=}}{{page needed|date=May 2011}} A recent genetic study of ]{{sfn|Hailer|Helander|Folkestad|Ganusevich|2007|p=}} is consistent with this idea. Greenlandic white-tailed eagles are, on ]ary time scales, a relatively recently founded population that has not yet accumulated a lot of unique genetic characteristics. However, the population appears to be demographically isolated and deserves special protection. | ||
| The White-tailed Eagle forms a ] with the ]. These diverged from other sea eagles at the beginning of the early ] (c. 10 ]) at the latest, possibly (if the most ancient fossil record is correctly assigned to this genus) as early as the early or middle ], about 28 mya ago. |
The White-tailed Eagle forms a ] with the ]. These diverged from other sea eagles at the beginning of the early ] (c. 10 ]) at the latest, possibly (if the most ancient fossil record is correctly assigned to this genus) as early as the early or middle ], about 28 mya ago.{{sfn|Wink|Heidrich|Fentzloff|1996}} | ||
| As in other sea-eagle species pairs, this one consists of a white-headed (the Bald Eagle) and a tan-headed species. They probably diverged in the North ], spreading westwards into Eurasia and eastwards into ]. Like the third northern species, ], they have yellow talons, beaks, and eyes in adults. | As in other sea-eagle species pairs, this one consists of a white-headed (the Bald Eagle) and a tan-headed species. They probably diverged in the North ], spreading westwards into Eurasia and eastwards into ]. Like the third northern species, ], they have yellow talons, beaks, and eyes in adults. | ||
| ==Diet== | == Diet == | ||
| ]]] | ]]] | ||
| Line 52: | Line 52: | ||
| == Breeding == | == Breeding == | ||
| ]s over the ]]] | ]s over the ]]] | ||
| White-tailed Eagles are sexually mature at four or five years of age. They pair for life, though if one dies replacement can occur quickly. A bond is formed when a permanent home range is chosen. They have a characteristic aerial courtship display which culminates in the pair locking talons mid-air and whirling earthwards in series of spectacular cartwheels. White-tailed Eagles are much more vocal than Golden Eagles, particularly during the breeding season and especially the male when near the eyrie. Calls can sometimes take on the form of a duet between the pair. |
White-tailed Eagles are sexually mature at four or five years of age. They pair for life, though if one dies replacement can occur quickly. A bond is formed when a permanent home range is chosen. They have a characteristic aerial courtship display which culminates in the pair locking talons mid-air and whirling earthwards in series of spectacular cartwheels. White-tailed Eagles are much more vocal than Golden Eagles, particularly during the breeding season and especially the male when near the eyrie. Calls can sometimes take on the form of a duet between the pair. | ||
| The nest is a huge edifice of sticks in a ] or on a coastal ]. Being faithful to their territories, once they breed, nests are often reused, sometimes for decades by successive generations of birds; one nest in Iceland has been in use for over 150 years.{{sfn|Snow|Perrins|1998|p=}}{{page needed|date=May 2011}} In ], trees have been known to collapse under the weight of enormous, long established nests. | The nest is a huge edifice of sticks in a ] or on a coastal ]. Being faithful to their territories, once they breed, nests are often reused, sometimes for decades by successive generations of birds; one nest in Iceland has been in use for over 150 years.{{sfn|Snow|Perrins|1998|p=}}{{page needed|date=May 2011}} In ], trees have been known to collapse under the weight of enormous, long established nests. | ||
| Line 59: | Line 61: | ||
| The territory of the White-tailed Eagle ranges between 30 and 70 km², normally in sheltered coastal locations. Sometimes they are found inland by lakes and along rivers. The territory of the White-tailed Eagles can overlap with the territory of the Golden Eagle, and competition between the two species is limited. Golden Eagles prefer mountains and moorland, while the White-tailed Eagle prefers the coast and the sea. | The territory of the White-tailed Eagle ranges between 30 and 70 km², normally in sheltered coastal locations. Sometimes they are found inland by lakes and along rivers. The territory of the White-tailed Eagles can overlap with the territory of the Golden Eagle, and competition between the two species is limited. Golden Eagles prefer mountains and moorland, while the White-tailed Eagle prefers the coast and the sea. | ||
| Mated pairs produce one to three ] per year. The eggs are laid two to five days apart in March or April and are incubated for 38 days by both parents. Once hatched, chicks are quite tolerant of one another, although the first hatched is often larger and dominant at feeding times. The female does most of the brooding and direct feeding, with the male taking over now and then. Young are able to feed themselves from five to six weeks and they fledge at eleven to twelve weeks, remaining in the vicinity of the nest, dependent on their parents for a further six to ten weeks. The sex of nestlings can be identified using field methods, or using ]. |
Mated pairs produce one to three ] per year. The eggs are laid two to five days apart in March or April and are incubated for 38 days by both parents. Once hatched, chicks are quite tolerant of one another, although the first hatched is often larger and dominant at feeding times. The female does most of the brooding and direct feeding, with the male taking over now and then. Young are able to feed themselves from five to six weeks and they fledge at eleven to twelve weeks, remaining in the vicinity of the nest, dependent on their parents for a further six to ten weeks. The sex of nestlings can be identified using field methods, or using ].{{sfn|Helander|Hailer|Vilà|2007|p=}} | ||
| Surplus chicks are sometimes removed from nests to use in ] programs in areas where the species has died out. If left in the nest, they are often killed by the first-hatched sooner or later, as in most large eagles. | Surplus chicks are sometimes removed from nests to use in ] programs in areas where the species has died out. If left in the nest, they are often killed by the first-hatched sooner or later, as in most large eagles. | ||
| Line 65: | Line 67: | ||
| In such programs, the birds are raised in boxes on platforms in the tree canopy and fed in such a way that they cannot see the person supplying their food, until they are old enough to fly and thus find their own food. | In such programs, the birds are raised in boxes on platforms in the tree canopy and fed in such a way that they cannot see the person supplying their food, until they are old enough to fly and thus find their own food. | ||
| ==Near-extinction and recovery in Europe== | == Near-extinction and recovery in Europe == | ||
| ] in 1888.]] | ] in 1888.]] | ||
| ], ], Norway.]] | ], ], Norway.]] | ||
| White-tailed Eagles are ]s. Therefore, they tend to experience ] from environmental ] that are present in their prey, and also suffered intensive persecution by ]s and ]s who considered them (usually wrongly<ref name=halley/>) to be a threat to their ] and ]s. During the period 1800-1970, White-tailed Eagles in most of Europe underwent dramatic declines, and became extinct in many regions of western, central, and southern Europe. While Norway, Germany, Poland, and Iceland harboured the largest surviving populations, pockets of reproducing pairs remained in several other countries. |
White-tailed Eagles are ]s. Therefore, they tend to experience ] from environmental ] that are present in their prey, and also suffered intensive persecution by ]s and ]s who considered them (usually wrongly<ref name=halley/>) to be a threat to their ] and ]s. During the period 1800-1970, White-tailed Eagles in most of Europe underwent dramatic declines, and became extinct in many regions of western, central, and southern Europe. While Norway, Germany, Poland, and Iceland harboured the largest surviving populations, pockets of reproducing pairs remained in several other countries.{{sfn|Hailer|Helander|Folkestad|Ganusevich|2006|p=}} Intense conservation actions throughout much of the remaining European distribution range (legal protection to decrease hunting, protection of breeding sites, and winter feeding) led to a recovery of many local populations. Since the 1980s, the European White-tailed Eagle population has recovered steadily, and is spreading back westward. It has today recolonised several traditional breeding areas in Europe and the recovery is still on-going, assisted in ] and the ] by reintroduction schemes.{{sfn|Snow|Perrins|1998|p=}}{{page needed|date=May 2011}}<ref name="bwp" /> | ||
| Some threats still remain, notably illegal persecution by gamebird shooting interests and egg thieves in Scotland,<ref name="rspb">RSPB: </ref> and a new threat from ]s is emerging with significant mortality (considerably in excess of the area's population productivity) occurring at the Smøla Windfarm in Norway.<ref>BirdLife International: </ref><ref>Birding News: </ref> | Some threats still remain, notably illegal persecution by gamebird shooting interests and egg thieves in Scotland,<ref name="rspb">RSPB: </ref> and a new threat from ]s is emerging with significant mortality (considerably in excess of the area's population productivity) occurring at the Smøla Windfarm in Norway.<ref>BirdLife International: </ref><ref>Birding News: </ref> | ||
| Line 74: | Line 76: | ||
| It was successfully reintroduced to the ], in the ] archipelago in ], in 1975 and now breeds throughout the ] and the mainland coast of ]. One of its Gaelic names is 'iolaire sùil na grèine' or 'eagle of the sunlit eye.'<ref name="Scotland. Scottish Natural Heritage 2009. p. 49" /> In August 2008 fifteen chicks raised in Norway were released at a secret location in ], in expectation of reintroducing the species in the east coast of Scotland as well.<ref> 13 August 2008. Accessed 13 August 2008.</ref> The White-tailed Eagle is still a rare breeder in Britain following its extinction and reintroduction, with 36 pairs in 2006 and 40 in 2008.<ref name="Scotland. Scottish Natural Heritage 2009. p. 49" />{{sfn|Snow|Perrins|1998|p=}}{{page needed|date=May 2011}}<ref name="rspb" /> | It was successfully reintroduced to the ], in the ] archipelago in ], in 1975 and now breeds throughout the ] and the mainland coast of ]. One of its Gaelic names is 'iolaire sùil na grèine' or 'eagle of the sunlit eye.'<ref name="Scotland. Scottish Natural Heritage 2009. p. 49" /> In August 2008 fifteen chicks raised in Norway were released at a secret location in ], in expectation of reintroducing the species in the east coast of Scotland as well.<ref> 13 August 2008. Accessed 13 August 2008.</ref> The White-tailed Eagle is still a rare breeder in Britain following its extinction and reintroduction, with 36 pairs in 2006 and 40 in 2008.<ref name="Scotland. Scottish Natural Heritage 2009. p. 49" />{{sfn|Snow|Perrins|1998|p=}}{{page needed|date=May 2011}}<ref name="rspb" /> | ||
| On 22 May 2006 it was announced that a pair of White-tailed Eagles was breeding in the ] nature reserve in the ]. They arrived on their own, not as a reintroduction. This is the first time the bird has bred in the Netherlands in modern times. In 2007, 2008 and 2009 the eagles returned to their nest.<ref>The Dutch national forestry, which owns the reserve, has put up a webcam trained on the nesting eagles </ref> In 2010, it turned out that the White-tailed eagle was also breeding in the Zwarte Meer nature district and in the Lauwersmeer area.<ref>{{cite web|author=Van onze verslaggever Caspar Janssen |url=http://www.volkskrant.nl/binnenland/article1362673.ece/Zeearend_nestelt_zich_in_Nederland/ |title=Zeearend nestelt zich in Nederland - Binnenland - VK |publisher=Volkskrant.nl |date= |accessdate=2011-05-30}}</ref> | On 22 May 2006 it was announced that a pair of White-tailed Eagles was breeding in the ] nature reserve in the ]. They arrived on their own, not as a reintroduction. This is the first time the bird has bred in the Netherlands in modern times. In 2007, 2008 and 2009 the eagles returned to their nest.<ref>The Dutch national forestry, which owns the reserve, has put up a webcam trained on the nesting eagles </ref> In 2010, it turned out that the White-tailed eagle was also breeding in the Zwarte Meer nature district and in the Lauwersmeer area.<ref>{{cite web | author = Van onze verslaggever Caspar Janssen | url = http://www.volkskrant.nl/binnenland/article1362673.ece/Zeearend_nestelt_zich_in_Nederland/ | title = Zeearend nestelt zich in Nederland - Binnenland - VK |publisher = Volkskrant.nl | date = | accessdate = 2011-05-30 }}</ref> | ||
| The White-tailed Eagle is being reintroduced to ]. The program started in the summer of 2007. Fifteen-twenty young eagles from ] are being released each spring into the ] in the south-west of Ireland. This comprehensive project will last a number of years with many more eagles being released. The species has a rich history on the island but became extinct in Ireland in the 1800s due to persecution from landowners.<ref>RTÉ: </ref> | The White-tailed Eagle is being reintroduced to ]. The program started in the summer of 2007. Fifteen-twenty young eagles from ] are being released each spring into the ] in the south-west of Ireland. This comprehensive project will last a number of years with many more eagles being released. The species has a rich history on the island but became extinct in Ireland in the 1800s due to persecution from landowners.<ref>RTÉ: </ref> | ||
| Line 84: | Line 86: | ||
| Twenty more eagles are due for release in 2010 however Dr Allan Mee, in charge of the sea eagle project, stated "the continuing loss of eagles to poisoning had cast a shadow over the future of the ambitious programme."<ref>{{cite news| url = http://www.irishtimes.com/newspaper/ireland/2010/0504/1224269640141.html | title = Sea eagle death in Kerry park brings total to 13 | newspaper = The Irish Times | date = 2010-05-04 | accessdate = 2011-05-30 }}</ref> | Twenty more eagles are due for release in 2010 however Dr Allan Mee, in charge of the sea eagle project, stated "the continuing loss of eagles to poisoning had cast a shadow over the future of the ambitious programme."<ref>{{cite news| url = http://www.irishtimes.com/newspaper/ireland/2010/0504/1224269640141.html | title = Sea eagle death in Kerry park brings total to 13 | newspaper = The Irish Times | date = 2010-05-04 | accessdate = 2011-05-30 }}</ref> | ||
| Studies of ] and ] in White-tailed Eagles from North-central Europe have shown that the recovering European population has retained appreciable amounts of ], implying low risk of ] (a serious concern in species with low ]). Therefore, the recovery of this formerly endangered species is a true success story for nature conservation. The story also shows how local protection of a species can be successful, and important for preserving the species' evolutionary potential. |
Studies of ] and ] in White-tailed Eagles from North-central Europe have shown that the recovering European population has retained appreciable amounts of ], implying low risk of ] (a serious concern in species with low ]). Therefore, the recovery of this formerly endangered species is a true success story for nature conservation. The story also shows how local protection of a species can be successful, and important for preserving the species' evolutionary potential.{{sfn|Hailer|Helander|Folkestad|Ganusevich|2006|p=}}<ref name="thesis">Frank Hailer (2006) Conservation genetics of the white-tailed eagle ''(Haliaeetus albicilla)''. PhD thesis, Uppsala University, Sweden. </ref>{{sfn|Hailer|Gautschi|Helander|2005|p=}} | ||
| == Heraldry == | == Heraldry == | ||
| Line 109: | Line 111: | ||
| }} | }} | ||
| </ref> | </ref> | ||
| }} | }} | ||
| Line 143: | Line 144: | ||
| | ref = harv | | ref = harv | ||
| }} | }} | ||
| * {{cite doi | 10.1111/j.1471-8286.2005.01122.x }} | |||
| * {{cite doi | 10.1098/rsbl.2006.0453 }} | |||
| * {{cite doi | 10.1111/j.1365-2699.2007.01697.x }} | |||
| * {{cite doi | 10.1007/s10336-007-0156-y }} | |||
| * {{cite book | * {{cite book | ||
| | last = Snow | | last = Snow | ||
| Line 155: | Line 160: | ||
| | ref = harv | | ref = harv | ||
| }} | }} | ||
| * {{cite doi | 10.1016/S0305-1978(96)00049-X }}. The authors' reservations about using the generalised "2%" rate of ] have since proven to be well founded. | |||
| == Further reading == | == Further reading == | ||
| === Identification === | === Identification === | ||
| * ] (1988) The Co. Kerry Bald Eagle '']'' 1(12): 379-80 - describes plumage differences between Bald Eagle and White-tailed Eagle in juvenile plumage | * ] (1988) The Co. Kerry Bald Eagle '']'' 1(12): 379-80 - describes plumage differences between Bald Eagle and White-tailed Eagle in juvenile plumage | ||
| === Extinction in Scotland === | === Extinction in Scotland === | ||
| * Harvie-Brown, J. A. and Buckley, T. E. (1892). ''A Vertebrate Fauna of Argyll and the Inner Hebrides.'' Edinburgh : David Douglas. p. 104 - 107. | * Harvie-Brown, J. A. and Buckley, T. E. (1892). ''A Vertebrate Fauna of Argyll and the Inner Hebrides.'' Edinburgh : David Douglas. p. 104 - 107. | ||
| * Harvie-Brown, J. A. and Buckley, T. E. (1888). ''A Vertebrate Fauna of the Outer Hebrides.'' Edinburgh : David Douglas. p. 84 - 87. | * Harvie-Brown, J. A. and Buckley, T. E. (1888). ''A Vertebrate Fauna of the Outer Hebrides.'' Edinburgh : David Douglas. p. 84 - 87. | ||
| == External links == | == External links == | ||
| ⚫ | {{commons|Haliaeetus albicilla}} | ||
| * on the Internet Bird Collection | * on the Internet Bird Collection | ||
| * Birdpix.lt . | * Birdpix.lt . | ||
| Line 176: | Line 184: | ||
| * photos and voice of White-tailed Eagle | * photos and voice of White-tailed Eagle | ||
| * . BBC website. | * . BBC website. | ||
| ⚫ | {{commons|Haliaeetus albicilla}} | ||
| {{Buteoninae}} | {{Buteoninae}} | ||
Revision as of 06:18, 30 May 2011
| White-tailed Eagle | |
|---|---|
| |
| In captivity | |
| Conservation status | |
 Least Concern (IUCN 3.1) | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Falconiformes (or Accipitriformes, q.v.) |
| Family: | Accipitridae |
| Genus: | Haliaeetus |
| Species: | H. albicilla |
| Binomial name | |
| Haliaeetus albicilla (Linnaeus, 1758) | |
| |
| Light Green: nesting area Blue: wintering area Dark Green: all-year | |
| Synonyms | |
|
Falco albicilla Linnaeus, 1758 | |
The White-tailed Eagle (Haliaeetus albicilla), also known as the Sea Eagle, Erne (sometimes Ern), or White-tailed Sea-eagle, is a large bird of prey in the family Accipitridae which includes other raptors such as hawks, kites, and harriers. It is considered a close cousin of the Bald Eagle and occupies the same ecological niche, but in Eurasia.
Description
The White-tailed Eagle is a large bird, 69–92 cm (27–36 in) long with a 182–244 cm (72–96 in) wingspan. Females, weighing 4–6.9 kg (8.8–15.2 lbs), are slightly larger than males, which weigh 3.1-5.4 kg (6.8–12 lbs). It is the fourth largest eagle in the World. It has broad "barn door" wings, a large head and a thick "meat-cleaver" beak. The adult is mainly brown except for the paler head and neck, blackish flight feathers, distinctive white tail, and yellow bill and legs. In juvenile birds the tail and bill are darker, with the tail becoming white with a dark terminal band in sub-adults..
Some individuals have been found to live over 25 years, 21 years on average.
Distribution and systematics
.jpg)
This large eagle breeds in northern Europe and northern Asia. The largest population in Europe is found along the coast of Norway. The World population in 2008 stands at only 9,000 - 11,000 pairs. They are mostly resident, only the northernmost birds such as the eastern Scandinavian and Siberian population migrating south in winter.
Small disjunct resident populations occur in southwesternmost Greenland and western Iceland. The former has been proposed as a distinct subspecies groenlandicus based on their very large size and body proportions. However, the species is now considered monotypic and the size variation is clinal according to Bergmann's Rule. A recent genetic study of mitochondrial DNA is consistent with this idea. Greenlandic white-tailed eagles are, on evolutionary time scales, a relatively recently founded population that has not yet accumulated a lot of unique genetic characteristics. However, the population appears to be demographically isolated and deserves special protection.
The White-tailed Eagle forms a species pair with the Bald Eagle. These diverged from other sea eagles at the beginning of the early Miocene (c. 10 mya) at the latest, possibly (if the most ancient fossil record is correctly assigned to this genus) as early as the early or middle Oligocene, about 28 mya ago.
As in other sea-eagle species pairs, this one consists of a white-headed (the Bald Eagle) and a tan-headed species. They probably diverged in the North Pacific, spreading westwards into Eurasia and eastwards into North America. Like the third northern species, Steller's Sea Eagle, they have yellow talons, beaks, and eyes in adults.
Diet
The Eagle's diet is varied, including fish, birds, carrion, and, occasionally, small mammals. Many birds live almost wholly as scavengers, regularly pirating food from otters and other birds, but this eagle can be a powerful hunter as well. Locally, this species may compete fiercely with Golden Eagles over the rabbits and hares either eagle may catch. The daily food requirement is in the region of 500-600 g. Although a less active hunter than the Golden Eagle, and usually losing out to them in direct competition for a single food item, they can exist at higher population densities and out-compete Golden Eagles because of their longer gut and more efficient digestive system, being able to live better with less food.
In the Baltic, the diet of the sea eagle consists mainly of sea birds (from the Little Tern to the Great Skua) and pike. Recently they are reported to have attacked and eaten great cormorants. The cormorant is an invading species in the Baltic, and the sea eagle may prove a valuable culler of the cormorant population.
Breeding
White-tailed Eagles are sexually mature at four or five years of age. They pair for life, though if one dies replacement can occur quickly. A bond is formed when a permanent home range is chosen. They have a characteristic aerial courtship display which culminates in the pair locking talons mid-air and whirling earthwards in series of spectacular cartwheels. White-tailed Eagles are much more vocal than Golden Eagles, particularly during the breeding season and especially the male when near the eyrie. Calls can sometimes take on the form of a duet between the pair.
The nest is a huge edifice of sticks in a tree or on a coastal cliff. Being faithful to their territories, once they breed, nests are often reused, sometimes for decades by successive generations of birds; one nest in Iceland has been in use for over 150 years. In Scandinavia, trees have been known to collapse under the weight of enormous, long established nests.
The territory of the White-tailed Eagle ranges between 30 and 70 km², normally in sheltered coastal locations. Sometimes they are found inland by lakes and along rivers. The territory of the White-tailed Eagles can overlap with the territory of the Golden Eagle, and competition between the two species is limited. Golden Eagles prefer mountains and moorland, while the White-tailed Eagle prefers the coast and the sea.
Mated pairs produce one to three eggs per year. The eggs are laid two to five days apart in March or April and are incubated for 38 days by both parents. Once hatched, chicks are quite tolerant of one another, although the first hatched is often larger and dominant at feeding times. The female does most of the brooding and direct feeding, with the male taking over now and then. Young are able to feed themselves from five to six weeks and they fledge at eleven to twelve weeks, remaining in the vicinity of the nest, dependent on their parents for a further six to ten weeks. The sex of nestlings can be identified using field methods, or using DNA.
Surplus chicks are sometimes removed from nests to use in reintroduction programs in areas where the species has died out. If left in the nest, they are often killed by the first-hatched sooner or later, as in most large eagles.
In such programs, the birds are raised in boxes on platforms in the tree canopy and fed in such a way that they cannot see the person supplying their food, until they are old enough to fly and thus find their own food.
Near-extinction and recovery in Europe
White-tailed Eagles are apex predators. Therefore, they tend to experience bioaccumulation from environmental pollutants that are present in their prey, and also suffered intensive persecution by shepherds and gamekeepers who considered them (usually wrongly) to be a threat to their livestock and gamebirds. During the period 1800-1970, White-tailed Eagles in most of Europe underwent dramatic declines, and became extinct in many regions of western, central, and southern Europe. While Norway, Germany, Poland, and Iceland harboured the largest surviving populations, pockets of reproducing pairs remained in several other countries. Intense conservation actions throughout much of the remaining European distribution range (legal protection to decrease hunting, protection of breeding sites, and winter feeding) led to a recovery of many local populations. Since the 1980s, the European White-tailed Eagle population has recovered steadily, and is spreading back westward. It has today recolonised several traditional breeding areas in Europe and the recovery is still on-going, assisted in Ireland and the United Kingdom by reintroduction schemes.
Some threats still remain, notably illegal persecution by gamebird shooting interests and egg thieves in Scotland, and a new threat from wind turbines is emerging with significant mortality (considerably in excess of the area's population productivity) occurring at the Smøla Windfarm in Norway.
It was successfully reintroduced to the Isle of Rum, in the Small Isles archipelago in Scotland, in 1975 and now breeds throughout the Western Isles and the mainland coast of Wester Ross. One of its Gaelic names is 'iolaire sùil na grèine' or 'eagle of the sunlit eye.' In August 2008 fifteen chicks raised in Norway were released at a secret location in Fife, in expectation of reintroducing the species in the east coast of Scotland as well. The White-tailed Eagle is still a rare breeder in Britain following its extinction and reintroduction, with 36 pairs in 2006 and 40 in 2008.
On 22 May 2006 it was announced that a pair of White-tailed Eagles was breeding in the Oostvaardersplassen nature reserve in the Netherlands. They arrived on their own, not as a reintroduction. This is the first time the bird has bred in the Netherlands in modern times. In 2007, 2008 and 2009 the eagles returned to their nest. In 2010, it turned out that the White-tailed eagle was also breeding in the Zwarte Meer nature district and in the Lauwersmeer area.
The White-tailed Eagle is being reintroduced to Ireland. The program started in the summer of 2007. Fifteen-twenty young eagles from Norway are being released each spring into the Killarney National Park in the south-west of Ireland. This comprehensive project will last a number of years with many more eagles being released. The species has a rich history on the island but became extinct in Ireland in the 1800s due to persecution from landowners.
In 2007, one hundred local sheep farmers gathered at Kerry airport to protest about the eagles arrival. Irish Farming Association Hill Committee chairman Mr O'Leary said he had no doubt the eagles would take lambs.
Since their reintroduction seven eagles have been confirmed poisoned in County Kerry, two are suspected of having been poisoned and one was shot. A 13th eagle released in Kerry was shot in Northern Ireland.
Twenty more eagles are due for release in 2010 however Dr Allan Mee, in charge of the sea eagle project, stated "the continuing loss of eagles to poisoning had cast a shadow over the future of the ambitious programme."
Studies of microsatellite and mitochondrial DNA in White-tailed Eagles from North-central Europe have shown that the recovering European population has retained appreciable amounts of genetic diversity, implying low risk of inbreeding depression (a serious concern in species with low population density). Therefore, the recovery of this formerly endangered species is a true success story for nature conservation. The story also shows how local protection of a species can be successful, and important for preserving the species' evolutionary potential.
Heraldry
The White-tailed Eagle is believed to be the White Eagle shown in the Polish Coat of Arms but also in the Serbian Coat of Arms. The sea eagle is often blazoned holding a fish (usually a pike) on his talons, distinguishing him from an ordinary eagle.
Prehistory
On Orkney, sea eagle bones have been found in 4000 year old burial mounds, suggesting that the birds were revered by the prehistoric people there, a belief strengthened by the Pictish stone carvings of sea eagles from Orkney.
Folklore
In the Shetland Isles fishermen believed that as soon as a sea eagle appeared fish would rise to the surface, belly up; this led to some fishermen using eagle fat, smeared on their bait, to increase their catch.
References
- Template:IUCN
- Etymology: Haliaeetus, New Latin for "sea-eagle". albicilla, "white-tailed", from Latin albi- "white" + cilla, "tail".
- Ferguson-Lees & Christie 2001.
- ^ The Nature of Scotland. Scottish Natural Heritage. Spring 2009. p. 49.
- ^ Snow & Perrins 1998.
- "Merikotkien määrä lisääntyy". MTV3.fi. Retrieved 2011-05-30.
- del Hoyo, Elliott & Sargatal 1994.
- Hailer et al. 2007. sfn error: no target: CITEREFHailerHelanderFolkestadGanusevich2007 (help)
- Wink, Heidrich & Fentzloff 1996. sfn error: no target: CITEREFWinkHeidrichFentzloff1996 (help)
- ^ Cramp, S., ed. (1980). The Birds of the Western Palearctic Vol. 2. Oxford ISBN 0-19-857505-X.
- ^ Halley, D. J. (1998). Golden and White-tailed Eagles in Scotland and Norway. Coexistence, competition and environmental degradation. British Birds 91 (5): 171-179.
- http://www.hs.fi/kotimaa/artikkeli/Turun+Sanomat+Merikotkat+oppineet+syömään+aikuisiakin+merimetsoja/1135256870866/?cmp=tm_etu_uusimmat_uutiset
- Helander, Hailer & Vilà 2007. sfn error: no target: CITEREFHelanderHailerVilà2007 (help)
- ^ Hailer et al. 2006. sfn error: no target: CITEREFHailerHelanderFolkestadGanusevich2006 (help)
- ^ RSPB: Birds of prey: Which birds are threatened?
- BirdLife International: Wind farm causes eagle deaths
- Birding News: Arrivals & Alarms
- (BBC News) " Birds released in secret location" 13 August 2008. Accessed 13 August 2008.
- The Dutch national forestry, which owns the reserve, has put up a webcam trained on the nesting eagles
- Van onze verslaggever Caspar Janssen. "Zeearend nestelt zich in Nederland - Binnenland - VK". Volkskrant.nl. Retrieved 2011-05-30.
- RTÉ: Rare eagle reintroduced to Ireland
- "Farmers protest at the arrival of the Eagles in 2007". Drimnaghbirdwatch.wordpress.com. Drimnagh Birdwatch. 2010-03-04. Retrieved 2011-05-30.
- "Sea eagle death in Kerry park brings total to 13". The Irish Times. 2010-05-04. Retrieved 2011-05-30.
- Frank Hailer (2006) Conservation genetics of the white-tailed eagle (Haliaeetus albicilla). PhD thesis, Uppsala University, Sweden. Thesis summary
- Hailer, Gautschi & Helander 2005. sfn error: no target: CITEREFHailerGautschiHelander2005 (help)
- "Polish Birds Directory". birds.poland.pl. Retrieved 2011-05-30.
- Sources
- del Hoyo, J.; Elliott, A.; Sargatal, J., eds. (1994). Handbook of the Birds of the World. Vol. 2. Barcelona: Lynx Edicions. ISBN 84-87334-15-6.
{{cite book}}: Invalid|ref=harv(help) - Ferguson-Lees, James; Christie, David A. (2001). Raptors of the World. Illustrated by Kim Franklin, David Mead, and Philip Burton. Houghton Mifflin. ISBN 978-0-618-12762-7. Retrieved 2011-05-29.
{{cite book}}: Invalid|ref=harv(help) - Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi: 10.1111/j.1471-8286.2005.01122.x , please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with
|doi= 10.1111/j.1471-8286.2005.01122.xinstead. - Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi: 10.1098/rsbl.2006.0453 , please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with
|doi= 10.1098/rsbl.2006.0453instead. - Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi: 10.1111/j.1365-2699.2007.01697.x , please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with
|doi= 10.1111/j.1365-2699.2007.01697.xinstead. - Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi: 10.1007/s10336-007-0156-y , please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with
|doi= 10.1007/s10336-007-0156-yinstead. - Snow, David W.; Perrins, Christopher M. (1998). The Birds of the Western Palearctic (Consise ed.). Oxford University Press. ISBN 0-19-854099-X.
{{cite book}}: Invalid|ref=harv(help) - Attention: This template ({{cite doi}}) is deprecated. To cite the publication identified by doi: 10.1016/S0305-1978(96)00049-X , please use {{cite journal}} (if it was published in a bona fide academic journal, otherwise {{cite report}} with
|doi= 10.1016/S0305-1978(96)00049-Xinstead.. The authors' reservations about using the generalised "2%" rate of molecular evolution have since proven to be well founded.
Further reading
Identification
- Grant, Peter J. (1988) The Co. Kerry Bald Eagle Twitching 1(12): 379-80 - describes plumage differences between Bald Eagle and White-tailed Eagle in juvenile plumage
Extinction in Scotland
- Harvie-Brown, J. A. and Buckley, T. E. (1892). A Vertebrate Fauna of Argyll and the Inner Hebrides. Edinburgh : David Douglas. p. 104 - 107.
- Harvie-Brown, J. A. and Buckley, T. E. (1888). A Vertebrate Fauna of the Outer Hebrides. Edinburgh : David Douglas. p. 84 - 87.
External links
- White-tailed eagle videos, photos & sounds on the Internet Bird Collection
- Birdpix.lt White-tailed Eagle photos.
- NaturePhoto-CZ: White-tailed Eagle photos. Retrieved 2006-NOV-30.
- RSPB: White-tailed Eagle. Retrieved 2006-NOV-30.
- Live webcam nest White-tailed Eagle, Oostvaardersplassen, Netherlands.
- Live webcam nest White-tailes Eagel, Herøy Municipal, Norway
- Fieldguide page on Flickr
- White-tailed Eagle Webcam and videos of nesting
- White-tailed Eagle photos photos and voice of White-tailed Eagle
- White-tailed Eagles in Scotland. BBC website.