Gavia pacifica

Coastal e Siberia and n N America; winters to Japan, s Baja.

The Pacific Loon can be found in the tundra regions of Alaska (USA) and northern Canada, on the northern tip of the United Kingdom, across Scandinavia to the far east of Russia. During winter its range expands to include the Pacific coast of Asia down to eastern China and North America down to Baja California (Mexico), much of the northern European coast and areas of the Mediterranean, Adriatic, Black and Caspian Seas¹.

The Pacific Loon is found along the Western Coast of the United States during the fall and winter, and in Northern Canada and Alaska where they migrate for the breeding months of the spring and summer.

Biogeographic Regions: nearctic (Native )

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) BREEDS: eastern Siberia from Arctic coast south to Anadyrland; Arctic coast of Alaska and Canada east to Baffin Island, south to southern Alaska, southwestern Yukon, northern Manitoba, and northwestern Quebec. WINTERS: south to Japan and along Pacific coast of North America south to Baja California and southern Sonora. In North America, areas of highest winter density include British Columbia around Vancouver Island, Monterey Bay in California, and near Point Whiteshed in Alaska (Root 1988). Casual/uncommon migrant inland in western U.S., very rare on east coast (NGS 1983).

The Pacific Loon's head is black which extends down the back of its neck and back where there are some mottled white spots. On its underside the color is white extending from its bill to its belly. Its average length is 66 cm.

Length: 66 cm

Weight: 1659 grams

G. ARCTICA has more white on the flanks at the waterline than does G. PACIFICA (see McCaskie et al. 1990, Roberson 1989, and Schulenberg 1989 for further details).

Habitat and Ecology

Systems

• Terrestrial
• Freshwater
• Marine

Pacific Loons reside for the most part along the eastern coast of the Pacific Ocean and Arctic Ocean along Canada's northern boundary. They can also be found in inland waterways and even lakes occurring along their migratory paths. They are sensitive to disturbances, especially those created by humans, and are most likely to occur in remote areas. Their nest are found right along the shoreline and will be abandoned if receding waters cause the nest to be too far from the edge of the water. Recently loons have become a pest on lakes that are commercially stocked with fish.

Aquatic Biomes: lakes and ponds; coastal

Depth range based on 1643 specimens in 1 taxon.
Water temperature and chemistry ranges based on 105 samples.

Environmental ranges
  Depth range (m): 0 - 0
  Temperature range (°C): 12.490 - 16.316
  Nitrate (umol/L): 0.240 - 3.951
  Salinity (PPS): 32.851 - 33.496
  Oxygen (ml/l): 5.685 - 6.169
  Phosphate (umol/l): 0.330 - 0.674
  Silicate (umol/l): 1.436 - 6.162

Graphical representation

Temperature range (°C): 12.490 - 16.316

Nitrate (umol/L): 0.240 - 3.951

Salinity (PPS): 32.851 - 33.496

Oxygen (ml/l): 5.685 - 6.169

Phosphate (umol/l): 0.330 - 0.674

Silicate (umol/l): 1.436 - 6.162
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

Comments: Nonbreeding: primarily seacoasts, bays and estuaries, less frequently on lakes and rivers (AOU 1983). In winter off central California, generally stays 2-8 km offshore (see Root 1988). In spring in southern California, migrants may be attracted to cool waters near the frontal boundaries of upwelling plumes, where loon prey is attracted by concentrations of zooplankton (Russell and Lehman 1994).

Nests on lakes/ponds in tundra or taiga. Usually nests on largest pond available (0.2-21 ha in one study area); selects ponds with islands or wet grassy areas. Nests on ground in scrape or on mound of material on ground in or very near water. Prefers to nest on island or at end of point extending into water (Johnson and Herter 1989).

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.

Highly migratory (small flocks); some travel 12,000 miles/years (Oberholser 1974); others move only to coastal waters near breeding range. Main migration in California: November-early December, late April-May; in southern California, spring migration peaks sometimes between mid-April and early May (Russell and Lehman 1994). Arrives southeastern Alaska by early May, arctic coast early June (sometimes late May). Peak fall migration in arctic Alaska late August-September (Johnson and Herter 1989).

The Pacific Loon feeds mainly on small fish and other aquatic life. Fishing is conducted beneath the surface where they make good use of well-developed air sacs, which allow them to pursue their prey for extended periods.

Comments: Feeds on fishes as well as crustaceans, mollusks, and aquatic insects; also eats aquatic seeds and some aquatic vegetation. Small shoal fishes often important in winter. Food obtained underwater during dives usually less than 1 minute. In some areas, nesting birds feed in lakes and ponds adjacent to their nest sites; in other areas, they make regular foraging flights to nearshore marine waters (Andres 1993).

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 81 to >300

10,000 - 1,000,000 individuals

Occurs singly, in pairs, or small groups. In winter off California, usually solitary or in pairs. Overall breeding density on arctic coastal plain estimated at about 1 pair per 200 ha; 5 nests observed on 1 pond of 21 ha (Johnsgard 1987). Egg predation by foxes, jaegers, and gulls sometimes is significant.

Pacific Loons are monogamous as long as the relationship is producing offspring. Breeding takes place in the spring and summer and is relatively noncompetitive once a mate is found for the males defend territories and mate with the same female each year. Loons are extremely awkward on land and venture out of the water only to nest. Broods usually include a total of two eggs, one of which is laid a few weeks before the second. This first egg also is the first to hatch, and it is brooded while the other egg is incubated. The older offspring assumes the dominant position in the nest and will be the first to be feed throughout its development. During times of inadequate food resources parents commonly continue feeding their older offspring, leading to the death of its younger sibling.

Breeding begins in early May in south, to mid-June in north. Both adults, in turn, incubate usually 2 eggs, 28-29 days. Hatching occurs in second half of July around Beaufort Sea (Johnson and Herter 1989). Young are tended by both parents, first fly at about 2 months, independent by about 3 months. Pair-bond apparently is life-long. Nest density is up to 2.6 per sq km in Alaska (Johnson and Herter 1989).

The following is a representative barcode sequence, the centroid of all available sequences for this species.

There are 8 barcode sequences available from BOLD and GenBank.  Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.  See the BOLD taxonomy browser for more complete information about this specimen and other sequences.

Download FASTA File

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 7
Specimens with Barcodes: 7
Species With Barcodes: 1

Canada

Rounded National Status Rank: N5B,N4N : N5B: Secure - Breeding, N4N: Apparently Secure - Nonbreeding

United States

Rounded National Status Rank: N5B,N4N : N5B: Secure - Breeding, N4N: Apparently Secure - Nonbreeding

Year Assessed

Assessor/s

Reviewer/s

Contributor/s

Justification

History

• 2008
  Least Concern
• 2004
  Least Concern

Pacific Loons are found in low concentrations during the winter months and in higher densities during the breeding months. This loon is combating human pressures well, but populations may decrease in the future. Recent studies are looking into the magnification of chemicals in the loon's body due to pollutants being added to the ecosystem and the loon being near the top of its food chain. The Pacific Loon's range is growing smaller as human development encroaches on its preferred habitats.

US Migratory Bird Act: protected

US Federal List: no special status

CITES: no special status

State of Michigan List: no special status

IUCN Red List of Threatened Species: least concern

Rounded Global Status Rank: G5 - Secure

Global Short Term Trend: Unknown

Global Long Term Trend: Unknown

Loons may be considered pests by commercial fishermen, who see them as competitors

Loons are aesthetically pleasing to observe in the nature and they are well known for their distinctive calls, which commonly occur at night.