[order] GAVIIFORMES | [family] Gaviidae | [latin] Gavia adamsii | [UK] Yellow-billed Loon | [FR] Plongeon a bec blanc | [DE] Gelbschnabel-Taucher | [ES] Colimbo de Adams | [NL] Geelsnavelduiker
Subspecies
Monotypic species
Genus
The genus gavidae is formed by five species exclusively from the Northern Hemisphere. All of them are rather large birds, breeding in the arctic and boreal zone of Eurasia and North America. Although ranges overlap a great deal, identification is pretty straightforward. The bills are so distinctive that it is easy to tell them apart, with the exeption of the Pacific and Arctic Divers which are rather similar.
Physical charateristics
Distinguished from other four loon species by the color of its bill, which is
yellow in breeding plumage and pale yellow to ivory in wintering plumage. Breeding plumage has
black upper parts with striking white spots, black head and neck with purple and green gloss, and
white chest and abdomen; non-breeding plumage is gray-brown. In all plumages, top part of
culmen (ridge of upper mandible) is yellow and distinguishable from other species of loon. Like other loons, this species has a highly modified leg and pelvis structure
well-adapted for swimming and diving but allowing almost no ability to walk; therefore, loons
place nests at the water’s edge and must take flight from wate
yellow in breeding plumage and pale yellow to ivory in wintering plumage. Breeding plumage has
black upper parts with striking white spots, black head and neck with purple and green gloss, and
white chest and abdomen; non-breeding plumage is gray-brown. In all plumages, top part of
culmen (ridge of upper mandible) is yellow and distinguishable from other species of loon. Like other loons, this species has a highly modified leg and pelvis structure
well-adapted for swimming and diving but allowing almost no ability to walk; therefore, loons
place nests at the water’s edge and must take flight from wate
Listen to the sound of Yellow-billed Loon
[audio:http://www.aviflevoland.nl/sounddb/Y/Yellow-billed Loon.mp3]
Copyright remark: Most sounds derived from xeno-canto
| wingspan min.: | 135 | cm | wingspan max.: | 150 | cm |
| size min.: | 77 | cm | size max.: | 90 | cm |
| incubation min.: | 24 | days | incubation max.: | 25 | days |
| fledging min.: | 70 | days | fledging max.: | 25 | days |
| broods: | 1 | eggs min.: | 1 | ||
| eggs max.: | 3 |
Range
North America, Eurasia : North
Habitat
Nests in low-lying treeless tundra regions, usually coastal, at around 62-74 degrees latitude on larger, clear, low-rimmed lakes. Breeding sites may also be on inland lakes or large river deltas with untapped lakes. Requires nesting
and brood-rearing lakes that are large enough to allow easy take-off from open water; form an icefree moat around shore in early spring; have clear water supporting a substantial overwintering population of small fishes; have segments of gently sloping shoreline in which nesting and brooding occurs; and have sheltered, vegetated areas, where young chicks rest and take refuge during disturbances. Nests placed at the water’s edge, typically in a low, gently sloping area. Deep open water with islands is a preferred habitat for nesting relative to its availability. Most nests are placed on the leeward lake or island shore.
and brood-rearing lakes that are large enough to allow easy take-off from open water; form an icefree moat around shore in early spring; have clear water supporting a substantial overwintering population of small fishes; have segments of gently sloping shoreline in which nesting and brooding occurs; and have sheltered, vegetated areas, where young chicks rest and take refuge during disturbances. Nests placed at the water’s edge, typically in a low, gently sloping area. Deep open water with islands is a preferred habitat for nesting relative to its availability. Most nests are placed on the leeward lake or island shore.
Reproduction
Pair formation occurs upon arrival on breeding territory; nests are constructed early to mid-June. Nests comprised of peat, pendant grass, sedges and sometimes lined with other vegetation. Nests from previous years frequently reused. Eggs are laid in June-July (some July nests represent renestings after loss of eggs). First nests generally are in mid-June in arctic Alaska, but peak nesting may be delayed by late ice melt on lakes. Clutch size: 2. Incubation, by both sexes, lasts 27-28 days. Chicks are dry and active within hours of hatching; brooding by both parents occurs in nest for about 3 days, then little on-shore brooding after about 9 days. In some areas, chicks 9-16 days old observed riding on parents back. Adults forage to feed young for up to 45 days. Reproductive maturity probably reached at or after 4 years.
Feeding habits
Forages in deep open water by repeated, lengthy dives. An opportunistic forager, takes prey in relation to availability and ease of capture, and consumes underwater. Chicks are fed small, minnow-sized fish. Important prey species include ninespine stickleback, least cisco, Alaska blackfish, fourhorn sculpin, isopods and amphipods
Conservation
This species has been uplisted to Near Threatened as it is suspected to be undergoing a moderately rapid population decline owing to unsustainable subsistence harvest. However, accurate data is lacking and further surveys need to be conducted to quantify the current rate of harvest.
Gavia arctica is a widespread breeder across much of northern Europe, which accounts
for less than a quarter of its global breeding range. Its European breeding population
is relatively small (<92,000 pairs), and underwent a large decline between 1970-1990. Although most European populations-including sizeable ones in Sweden and Finland-were stable or increased during 1990-2000, the species continued to decline in Norway and its Russian stronghold, and underwent a large decline (>30%) overall.
Consequently, it is provisionally evaluated as Vulnerable.
This bird is breeding in the arctic and boreal regions of Eurasia. The breeding population of the European Union, entirely restricted to Scotland, amounts to 150-160 breeding pairs and seems stable (Tucker & Heath). Elsewhere this species is decreasing due to habitat changes, increasing disturbance by humans, predation, decreasing fish populations following over-fishing and acid rains and oil pollution at sea.
Breeds in northern Scotland and the Hebrides, over much of Scandinvia 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 and recently split Pacific Diver G. pacifica. 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. May also occur on Atlantic coast of North America.
Gavia arctica is a widespread breeder across much of northern Europe, which accounts
for less than a quarter of its global breeding range. Its European breeding population
is relatively small (<92,000 pairs), and underwent a large decline between 1970-1990. Although most European populations-including sizeable ones in Sweden and Finland-were stable or increased during 1990-2000, the species continued to decline in Norway and its Russian stronghold, and underwent a large decline (>30%) overall.
Consequently, it is provisionally evaluated as Vulnerable.
This bird is breeding in the arctic and boreal regions of Eurasia. The breeding population of the European Union, entirely restricted to Scotland, amounts to 150-160 breeding pairs and seems stable (Tucker & Heath). Elsewhere this species is decreasing due to habitat changes, increasing disturbance by humans, predation, decreasing fish populations following over-fishing and acid rains and oil pollution at sea.
Breeds in northern Scotland and the Hebrides, over much of Scandinvia 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 and recently split Pacific Diver G. pacifica. 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. May also occur on Atlantic coast of North America.
Migration
Migratory. Like Great Northern Diver, breeds on high latitude fresh waters but winters on salt water. Freshwater arrivals and departures linked to thawing and freezing; at sea mainly October-May; when late thaw breeding lakes not re-occupied until late June.
Distribution map
