Larus occidentalis

Habitat and Ecology

Systems

• Terrestrial
• Marine

Depth range based on 27649 specimens in 1 taxon.
Water temperature and chemistry ranges based on 9407 samples.

Environmental ranges
  Depth range (m): 0 - 0
  Temperature range (°C): 3.285 - 17.265
  Nitrate (umol/L): 0.038 - 4.675
  Salinity (PPS): 30.381 - 33.496
  Oxygen (ml/l): 5.540 - 7.715
  Phosphate (umol/l): 0.330 - 0.800
  Silicate (umol/l): 1.436 - 16.169

Graphical representation

Temperature range (°C): 3.285 - 17.265

Nitrate (umol/L): 0.038 - 4.675

Salinity (PPS): 30.381 - 33.496

Oxygen (ml/l): 5.540 - 7.715

Phosphate (umol/l): 0.330 - 0.800

Silicate (umol/l): 1.436 - 16.169
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

Comments: NON-BREEDING: at sea or along the coast; rocky shores and cliffs, bays, estuaries, beaches, garbage dumps. BREEDING: Nests typically on rocky ledges or grassy slopes near beaches on offshore islands; nests in greatest numbers on flatter sections of islands, usually in relatively open areas with bare rock or low vegetation (Spendelow and Patton 1988).

East North Pacific

The Western Gull is found on the Pacific coast of North America, ranging from Vancouver Island (Canada) to the southern tip of Baja California (Mexico), and breeding from north-west Washington (USA) to central Baja California¹.

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

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Transient

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: BREEDING: coastally from southwestern British Columbia south to west-central Baja California and Guadalupe Island. NON-BREEDING: southern British Columbia south to southern Baja California; rare in Hawaii.

Length: 64 cm

Weight: 1011 grams

Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.

Locally Migrant: Yes. At least some 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: No. No populations of this species make annual migrations of over 200 km.

Southern populations relatively sedentary.

Comments: Eats fish, crustaceans, mollusks, worms, garbage. Catches food, scavenges after ships, or pirates fish from pelicans, cormorants, and other birds. May feed at garbage dumps or along beaches. Sometimes eats eggs and young of other birds (e.g., murres, Spear 1993). See Spear (1988) for information on feeding areas of gulls from Farallon Islands.

See Spear (1988) for information on movements of gulls breeding and reared on Farallon Islands.

Maximum longevity: 27.8 years (wild)

Clutch size usually 3. Incubation 25-29 days, by both sexes. Young semi-precocial, can fly at about 49 days, independent at average age of 70 days on offshore island; parental care may last longer along coast (Spear et al. 1986). Colonies tend to be small; less than 5 pairs not uncommon; less than 10% of colonies >100 pairs (Spendelow and Patton 1988).

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

There are 4 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: 4
Specimens with Barcodes: 4
Species With Barcodes: 1

Year Assessed

Assessor/s

Reviewer/s

Contributor/s

Justification

History

• 2008
  Least Concern
• 2004
  Least Concern

Canada

Rounded National Status Rank: NNA - Not Applicable

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure