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Pacific
Diver, Gavia pacifica, Belyaka Neset.
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Yellow-billed Loon, Gavia adamsii, Belyaka Neset
Common
Loon, Gavia immer
Red-throated Loon, Gavia stellata, Belyaka Neset.
Red-throated loon (Gavia stellata), Belyaka Spit.
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The calls of Chukotka's four loon species are among the most
beautiful sounds of the tundra.
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Yellow-billed loons (G. adamsii), Belyaka Spit
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Pacific
loons, Gavia. pacifica, Belyaka Spit.
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Gaviiformes
Gaviidae Loon family
Gavia stellata, Red-throated Loon
Gavia arctica, Arctic Loon
Gavia pacifica, Pacific Loon
Gavia immer, Great Northern Loon
Gavia adamsii, Yellow-billed Loon
The loons (North America) or divers (UK/Ireland) are a group
of aquatic birds found in many parts of North America and northern
Eurasia (Europe, Asia and debatably Africa). All living species
of loons are members of the genus, Gavia, family.
Loons are excellent swimmers, using their feet to propel themselves
above and under water while their wings provide assistance.
Because their feet are far back on the body, loons are poorly
adapted to moving on land, and usually avoid going onto land,
except when nesting.
All loons are decent fliers, though the larger species have
some difficulty taking off and thus must swim into the wind
to pick up enough velocity to become airborne. Only the Red-throated
Diver, Gavia stellata, can take off from land. Once airborne,
their considerable stamina allows them to migrate
long distances southwards in winter, where they reside in coastal
waters.
Loons can live as long as 30 years.
Loons find their prey by sight. They eat mainly fish, supplemented
with amphibians, crustaceans and similar mid-sized aquatic fauna.
Specifically, they have been noted to feed on crayfish, frogs,
snails, salamanders and leeches. They prefer clear lakes because
they can more easily see their prey through the water. The loon
uses its pointy bill to stab or grasp prey.
They eat vertebrate prey headfirst to facilitate swallowing,
and swallow all their prey whole. |
Red-throated Loon, Gavia
stellata
An
adult Red-throated Loon in breeding plumage swimming
in Iceland.
Photo:
Ómar Runólfsson, http://en.wikipedia.org/wiki/File:Gavia_stellata_-Iceland_-swimming-8.jpg
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The Red-throated Loon or Red-throated Diver, Gavia stellata,
is a migratory
aquatic bird found in the northern
hemisphere. It breeds primarily in Arctic regions, and winters
in northern coastal waters. It is the most widely
distributed member of the loon or diver family. Ranging from
5567 centimetres (2226 in) in length, the Red-
throated Loon is the smallest and lightest of the world's loons.
In winter, it is a nondescript bird, greyish above
fading to white below. During the breeding season, it acquires
the distinctive reddish throat patch which is the
basis for its common name. Fish form the bulk of its diet, though
amphibians, invertebrates and plant material
are sometimes eaten as well. A monogamous species, the Red-throated
Loon forms long-term pair bonds.
Both members of the pair help to build the nest, incubate the
eggs (generally two per clutch) and feed the
hatched young.
The Red-throated Loon has a large global population and a significant
global range, though some populations are declining. Oil spills,
habitat degradation, pollution and fishing nets are among the
major threats this species faces. Natural predatorsincluding
various gull species, and both Red foxes and Arctic
Foxes, will take eggs and young. The species is protected
by a number of international treaties.
Source:
http://en.wikipedia.org/wiki/Red-throated_Loon |
Black-throated Loon, Gavia
arctica
Arctic
Loon Gavia arctica on nest
http://digitalrepository.fws.gov/cdm4/item_viewer.php?CISOROOT=/natdiglib&CISOPTR=744&CISOBOX=1&REC=4
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The Black-throated Loon, Gavia arctica, is a migratory
aquatic bird found in the northern hemisphere.
The species is known as an Arctic Loon in North America and
the Black-throated Diver in Eurasia, its current
name is a compromise proposed by the International Ornithological
Committee.
It breeds in Eurasia and occasionally in western Alaska. It
winters at sea, as well as on large lakes over a much wider
range.
Breeding adults are 58 to 77 cm in length with a 100 to 130
cm wingspan, shaped like a smaller, sleeker version
of the Great Northern Diver. Body mass is reportedly from 23.4
kg. They have a grey head, black throat,
white underparts and chequered black-and-white mantle. Non-breeding
plumage is drabber with the chin and
foreneck white. Its bill is grey or whitish and dagger-shaped.
In all plumages a white flank patch distinguishes
this species from all other divers including the otherwise almost
identical Pacific Diver.
This species, like all divers, is a specialist fish-eater, catching
its prey underwater. It flies with neck outstretched.
It feeds on fish, insects, crustaceans and amphibians.
The calls include a yodelling high-pitched wail and harsh growls,
similar but lower pitched than Pacific Loon.
Source:
http://en.wikipedia.org/wiki/Black-throated_Loon |
Pacific Loon, Gavia
pacifica
Pacific
Loon, Gavia pacifica
Photo:
Tim Bowman, USFWS
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The Pacific Loon or Pacific Diver, Gavia pacifica, is
a medium-sized member of the loon, or diver, family.
It breeds on deep lakes in the tundra region of Alaska and northern
Canada as far east as Baffin Island, and in Russia east of the
Lena River.
Unlike other loons/divers, this bird may migrate
in flocks. It winters at sea, mainly on the Pacific coast, or
on large lakes over a much wider range, including China, Japan,
North Korea, South Korea, USA and Mexico.
It has occurred as a vagrant to Greenland, Hong Kong, Great
Britain, Spain, and Finland.
Breeding adults are like a smaller sleeker version of Great
Northern Diver/Common Loon.
They measure 5874 cm in length, 110128 cm in wingspan
and weigh 12.5 kg. They have a grey head, black throat,
white underparts and chequered black-and-white mantle. Non-breeding
plumage is drabber with the chin and foreneck white. Its bill
is grey or whitish and dagger-shaped. In all plumages, lack
of a white flank patch distinguishes this species from the otherwise
very similar Black-throated Diver/Arctic Loon.
This species, like all divers/loons, is a specialist fish-eater,
catching its prey underwater.
It flies with neck outstretched.
The call is a yodelling high-pitched wailing, as well as harsh
growls and barks.
Source:
http://en.wikipedia.org/wiki/Pacific_Loon |
Great Northern Loon , Gavia
immer
A
Great Northern Loon in Minocqua, Wisconsin, USA.
Photo: John Picken, http://en.wikipedia.org/wiki/File:Gavia_immer_-Minocqua,_Wisconsin,_USA_-swimming-8.jpg
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The Great Northern Loon, Gavia immer, is a large member
of the loon, or diver, family of birds.
The species is known as the Common Loon in North America and
the Great Northern Diver in Eurasia;
its current name is a compromise proposed by the International
Ornithological Committee.
Adults can range from 61 to 100 cm in length with a 122152
cm wingspan, slightly smaller than the similar
Yellow-billed Loon (or "White-billed Diver"). The
weight can vary from 1.6 to 8 kg. On average a
Great Northern Loon is about 81 cm long, has a wingspan of 136
cm , and weighs about 4.1 kg .
Breeding adults have a black head, white underparts, and a checkered
black-and-white mantle. Non-breeding plumage is brownish, with
the chin and foreneck white. The bill is black-blue and held
horizontally.
The bill colour and angle distinguish this species from the
similar Yellow-billed Loon.
The Great Northern Loon breeds in Canada, parts of the northern
United States, Greenland, and Alaska.
There is a smaller population (ca. 3,000 pairs) in Iceland.
On isolated occasions they have bred in the far north
of Scotland. The female lays 1 to 3 eggs on a hollowed-out mound
of dirt and vegetation very close to water.
Both parents build the nest, sit on the egg or eggs, and feed
the young.
This species winters on sea coasts or on large lakes over a
much wider range in Europe and the British Isles
as well as in North America.
Source:
http://en.wikipedia.org/wiki/Great_Northern_Loon |
Yellow-billed Loon, Gavia adamsii
Juvenile
Yellow-billed Loon, a rare visitor to the California
coast
Photo: Len Blumin, http://en.wikipedia.org/wiki/File:Gavia_adamsii.jpg
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The Yellow-billed Loon, Gavia adamsii, also known as
the White-billed Diver, is the largest member of the
loon or diver family. Breeding adults have a black head, white
underparts and chequered black-and-white mantle. Non-breeding
plumage is drabber with the chin and foreneck white. The main
distinguishing feature from Great Northern Loon is the longer
straw-yellow bill which, because the culmen is straight, appears
slightly uptilted.
It breeds in the Arctic and winters mainly at sea along the
coasts of the northern Pacific Ocean and northwestern Norway;
it also sometimes overwinters on large inland lakes. It occasionally
strays well south of its normal
wintering range, and has been recorded as a vagrant in more
than 22 countries. This species, like all divers, is a specialist
fish-eater, catching its prey underwater.
Its call is an eerie wailing, lower pitched than Great Northern
Diver.
Yellow-billed
Loon Gavia adamsii off Hwajin Po, January 5th 2009,
Photo © Thomas Langenberg, http://www.birdskorea.org/
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With a length of 76 to 97 cm, a wingspan of 135 to 160 cm, and
a weight ranging from 4 to 6.4 kg, so
the Yellow-billed Loon is the largest member of the loon (diver)
family. The adult is primarily black and white
in breeding plumage, with a purple gloss on its head and neck.
The Yellow-billed Loon is an Arctic species, breeding primarily
along the coasts of the Arctic Ocean as far north
as 78° N and wintering on sheltered coastal waters of the
northern Pacific Ocean and the northwestern coast of
Norway. It has been recorded as a breeding bird in Russia, Canada
and the United States. Though it winters primarily to the north
of 50° N, its winter range extends south to 35° N off
the coast of Japan, and it has been recorded as a vagrant in
more than 20 countries, including some as far south as Mexico
and Spain.
Though it prefers freshwater pools or lakes in the tundra, the
Yellow-billed Loon will also breed along rivers,
estuaries or the coast in low-lying areas of the Arctic; in
general, it avoids forested areas. Breeding typically
starts in early June, though it is dependent on the timing of
the spring thaw. Like all members of its family, the
Yellow-billed Loon builds a nest of plant material very close
to the edge of the water. The female lays two eggs.
The Yellow-billed Loon is a specialist fish eater, though it
also takes crustaceans, molluscs and annelids.
It dives in pursuit of prey, which is caught underwater.
Source:
http://en.wikipedia.org/wiki/Yellow-billed_Loon |
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