(Redirected from Common Loon)
The 'Great Northern Diver', known in
North America as the 'Common Loon' (''Gavia immer'' [GAY-vee-ah IM-mer]), is a large member of the
loon, or diver,
family.
Adults can range from 61-100 cm (24-40 inches) in length with a 122-152 cm (4-5-foot) wingspan, slightly smaller than the similar
White-billed Diver or "Yellow-billed Loon". The weight can vary from 1.6 to 8 kg (3.6 to 17.6 lbs). On average a Common Loon is about 81 cm (32 inches) long, has a wingspan of 136 cm (54 inches), and weighs about 4.1 kg (9 lbs).
The Great Northern Diver breeds in
Canada, parts of the northern
United States,
Greenland, and
Alaska. There is a smaller
population (ca. 3000 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 Northern
Europe and the
British Isles as well as in
North America.
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 grey or whitish and held horizontally. The bill colour and angle distinguish this species from the similar
White-billed Diver.
This
species, like all divers, is a specialist
fish-eater, catching its prey underwater, diving as deep as 200 feet (60 m). Freshwater diets consist of
pike,
perch,
sunfish,
trout and
bass; salt water diets consist of
rock fish,
flounders,
sea trout and
herring. The bird needs a long distance to gain momentum for take-off, is ungainly on landing. It is clumsy on the land due to the position of the legs at the rear of the body, ideal for diving but not well-suited for walking. Birds land on water skimming along on their bellies to slow down rather than their feet, as these are set too far back. It swims gracefully on the surface, dives as well as any flying bird, and flies competently for hundreds of miles in migration. It flies with its neck outstretched, usually calling a particular tremolo that can be used to identify a flying loon.
These birds have disappeared from some lakes in eastern
North America due to the effects of
acid rain and
pollution, as well as lead poisoning from fishing sinkers and mercury contamination from industrial waste. Artificial floating nesting platforms have been provided for loons in some
lakes to reduce the impact of changing water levels due to
dams and other human activities.
The Great Northern Diver is one of the
species to which the ''Agreement on the Conservation of African-Eurasian Migratory Waterbirds'' (
AEWA) applies.
This diver is well-known in
Canada, appearing on the
"loonie" coin and
$20 bill, and is the
provincial bird of
Ontario. Also, it is the
state bird of
Minnesota.
The voice and appearance of the Common Loon has made it prominent in several
Native American tales. These include a story of a loon which created the world in a
Chippewa story; a
Micmac saga describes Kwee-moo, the loon who was a special messenger of Glooscap, the tribal hero; native tribes of
British Columbia believed that an excess of calls from this
bird predicted
rain, and even brought it; and the tale of the loon’s necklace was handed down in many versions among Pacific Coast peoples. Folk names include big loon, black-billed loon, call-up-a-storm, ember-goose, greenhead, guinea duck, imber diver, ring-necked loon, and walloon.
''Gavia'' is
Latin for "sea smew" (although divers are not
Smew). The specific meaning of ''immer'' either is:
★ related to Swedish ''immer'' and ''emmer'', the grey or blackened ashes of a fire, referring to its dark plumage; or
★ Latin ''immergo'', to immerse, and ''immersus'', submerged.
References
★ Database entry includes justification for why this species is of least concern
External links
★
Loons
★
Stamps: Common Loon
★
Great Northern Diver videos on the Internet Bird Collection
★
DigiMorph.org—
CT scans of a Great Northern Diver skull
★
Great Northern Diver on Animal Diversity Web
★
USGS Information - Common Loon
★
Cornell Lab of Ornithology - Common Loon Information
★
South Dakota Birds - Common Loon Information and Photos