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;Gavia arctica | ;Gavia arctica | ||
− | [[Image:Arctic_Loon.jpg|thumb|550px|right|Photo by Digiscoper321]] | + | [[Image:Arctic_Loon.jpg|thumb|550px|right|Photo by Digiscoper321.<br/>Photo taken: western Sweden.]] |
==Identification== | ==Identification== | ||
− | + | Medium-sized diver between [[Red-throated Loon|Red-throated]] and [[Common Loon|Great Northern]] in build. Adult breeding: upperparts blackish with rectangular white spots on back, most prominent on scapulars, and white below with black and white streaks on sides of upper breast. Head and neck grey, palest on hindneck, with black and white vertical stripes on sides of neck bordering black throat patch. Adult non-breeding: Dark grey-brown on head and upperparts clearly demarcated from white throat and underparts. Crown and nape are paler than back (unlike [[Common Loon|Great Northern]]) and flanks often show a white patch visible on a swimming bird. Intermediate build and bill held straight are best identifying features but very difficult to separate from [[Pacific Loon|Pacific Diver]] and may not be possible with non-breeding birds. Length 68-73cm. Wingspan 120cm. | |
− | + | ==Distribution== | |
− | + | Breeds in northern [[Scotland]] and the [[Western Isles|Hebrides]], over much of Scandinavia and the Baltic states and across [[Russia]] to Sakhalin and Kamchatka, probably also northern [[China]]. Breeds in western [[Alaska]] but range unclear due to similarity of this species to the recently split [[Pacific Loon|Pacific Diver]]. | |
+ | In winter ranges from the Baltic south to Biscay, the northern Adriatic and Black and Caspian Seas and a vagrant on the North [[Africa]]n coast and the [[Canary Islands]]. In the far east winters off [[Japan]], [[China]] and [[Taiwan]]. The Siberian race has strayed to the Pacific coast of [[North America]]. | ||
+ | ==Taxonomy== | ||
+ | Also known as the Black-throated Diver. Three subspecies recognised. Nominate race breeds across [[Europe]] and [[Russia]] with ''sushkini'' from western Siberia and Central [[Asia]] and ''viridigularis'' (green-glossed throat patch) in north-eastern Siberia and western [[Alaska]]. | ||
− | + | ==Habitat== | |
+ | Breeds beside medium-large freshwater lakes, often with islands. On passage and in winter moves to coastal areas and occurs on estuaries, bays and sheltered seas. | ||
− | + | ==Behaviour== | |
− | + | Voice: Various wailing, croaking and quacking calls. | |
− | + | Breeding: Breeds early-May to September, begins mid-June in north of range. Nests beside water often on an island or spit, a shallow scrape or more rarely a substantial mound of vegetation built in shallow water. Eggs: 2 (1 in replacement clutch), olive-brown, sometimes more greenish with sparse black blotches (84 x 53mm). Incubated by both sexes for 28-29 days. Young tended by both sexes, feed themselves at 35 days and fly at about 60 days | |
+ | Diet: Fish, also molluscs and crustaceans caught during 45-120 second dives. | ||
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==Bird Song== | ==Bird Song== | ||
<flashmp3>Gavia arctica (song).mp3</flashmp3><br /> | <flashmp3>Gavia arctica (song).mp3</flashmp3><br /> |
Revision as of 18:01, 13 October 2007
- Gavia arctica
Identification
Medium-sized diver between Red-throated and Great Northern in build. Adult breeding: upperparts blackish with rectangular white spots on back, most prominent on scapulars, and white below with black and white streaks on sides of upper breast. Head and neck grey, palest on hindneck, with black and white vertical stripes on sides of neck bordering black throat patch. Adult non-breeding: Dark grey-brown on head and upperparts clearly demarcated from white throat and underparts. Crown and nape are paler than back (unlike Great Northern) and flanks often show a white patch visible on a swimming bird. Intermediate build and bill held straight are best identifying features but very difficult to separate from Pacific Diver and may not be possible with non-breeding birds. Length 68-73cm. Wingspan 120cm.
Distribution
Breeds in northern Scotland and the Hebrides, over much of Scandinavia and the Baltic states and across Russia to Sakhalin and Kamchatka, probably also northern China. Breeds in western Alaska but range unclear due to similarity of this species to the recently split Pacific Diver.
In winter ranges from the Baltic south to Biscay, the northern Adriatic and Black and Caspian Seas and a vagrant on the North African coast and the Canary Islands. In the far east winters off Japan, China and Taiwan. The Siberian race has strayed to the Pacific coast of North America.
Taxonomy
Also known as the Black-throated Diver. Three subspecies recognised. Nominate race breeds across Europe and Russia with sushkini from western Siberia and Central Asia and viridigularis (green-glossed throat patch) in north-eastern Siberia and western Alaska.
Habitat
Breeds beside medium-large freshwater lakes, often with islands. On passage and in winter moves to coastal areas and occurs on estuaries, bays and sheltered seas.
Behaviour
Voice: Various wailing, croaking and quacking calls.
Breeding: Breeds early-May to September, begins mid-June in north of range. Nests beside water often on an island or spit, a shallow scrape or more rarely a substantial mound of vegetation built in shallow water. Eggs: 2 (1 in replacement clutch), olive-brown, sometimes more greenish with sparse black blotches (84 x 53mm). Incubated by both sexes for 28-29 days. Young tended by both sexes, feed themselves at 35 days and fly at about 60 days
Diet: Fish, also molluscs and crustaceans caught during 45-120 second dives.
Bird Song
<flashmp3>Gavia arctica (song).mp3</flashmp3>
Listen in an external program