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Larus occidentalis

Audubon, 1839

Western Gull

G5Secure Found in 75 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
Least concernIUCN
Western Gull (Larus occidentalis). © Michael Long; Cornell Lab of Ornithology | Macaulay Library.
© Michael Long; Cornell Lab of Ornithology | Macaulay Library
Western Gull (Larus occidentalis). © Sasha Cahill; Cornell Lab of Ornithology | Macaulay Library.
© Sasha Cahill; Cornell Lab of Ornithology | Macaulay Library
Western Gull (Larus occidentalis). © Alison Davies; Cornell Lab of Ornithology | Macaulay Library.
© Alison Davies; Cornell Lab of Ornithology | Macaulay Library
Western Gull (Larus occidentalis). © Alex Chen; Cornell Lab of Ornithology | Macaulay Library.
© Alex Chen; Cornell Lab of Ornithology | Macaulay Library
Western Gull (Larus occidentalis). © Zane Pickus; Cornell Lab of Ornithology | Macaulay Library.
© Zane Pickus; Cornell Lab of Ornithology | Macaulay Library
Western Gull (Larus occidentalis). © Grigory Heaton; Cornell Lab of Ornithology | Macaulay Library.
© Grigory Heaton; Cornell Lab of Ornithology | Macaulay Library
Western Gull (Larus occidentalis). Photo by U.S. Fish & Wildlife Service, Public Domain (U.S. Government Work), via ECOS.
U.S. Fish & Wildlife Service, https://www.usa.gov/government-works
Identity
Unique IDELEMENT_GLOBAL.2.102574
Element CodeABNNM03180
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVertebrate Animal
IUCNLeast concern
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomAnimalia
PhylumCraniata
ClassAves
OrderCharadriiformes
FamilyLaridae
GenusLarus
Other Common Names
Gaviota Occidental (ES) Goéland d'Audubon (FR) western gull (EN)
Concept Reference
American Ornithologists' Union (AOU). 1998. Check-list of North American birds. Seventh edition. American Ornithologists' Union, Washington, D.C. [as modified by subsequent supplements and corrections published in The Auk]. Also available online: http://www.aou.org/.
Taxonomic Comments
Closely related to several other species within the Larus californicus complex; this complex poses one of the most complicated problems in ornithological systematics today. Frequently hybridizes (and may be conspecific) with L. glaucescens from southern British Columbia to western Oregon (AOU 1983).
Conservation Status
Rank MethodExpertise without calculation
Review Date2016-04-09
Change Date1996-11-27
Range Extent Comments
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.
Ecology & Habitat

Habitat

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).

Ecology

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

Reproduction

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).
Terrestrial Habitats
Sand/duneCliff
Other Nations (2)
CanadaNUN
ProvinceRankNative
British ColumbiaS3NYes
United StatesN5
ProvinceRankNative
CaliforniaSNRYes
WashingtonS4B,S4NYes
OregonS4Yes
Roadless Areas (75)
California (32)
AreaForestAcres
Arroyo SecoAngeles National Forest4,703
Arroyo SecoAngeles National Forest4,703
Black ButteLos Padres National Forest5,116
Black ButteLos Padres National Forest5,116
Blue Creek Rare ISix Rivers National Forest12,134
CamuesaLos Padres National Forest8,209
Chalk PeakLos Padres National Forest7,472
Chalk PeakLos Padres National Forest7,472
Chalk PeakLos Padres National Forest7,472
Dry LakesLos Padres National Forest17,043
Dry LakesLos Padres National Forest17,043
JuncalLos Padres National Forest12,289
JuncalLos Padres National Forest12,289
Malduce BuckhornLos Padres National Forest14,177
NordhoffLos Padres National Forest12,031
NordhoffLos Padres National Forest12,031
North Fork SmithSix Rivers National Forest37,898
North Fork SmithSix Rivers National Forest37,898
PacksaddleSix Rivers National Forest3,862
PacksaddleSix Rivers National Forest3,862
Red MountainAngeles National Forest8,034
Red MountainAngeles National Forest8,034
Santa CruzLos Padres National Forest21,182
Sespe - FrazierAngeles National Forest4,254
Sespe - FrazierAngeles National Forest4,254
TequepisLos Padres National Forest9,080
TrabucoCleveland National Forest23,341
TrabucoCleveland National Forest23,341
White LedgeLos Padres National Forest18,632
White LedgeLos Padres National Forest18,632
WildhorseCleveland National Forest1,483
WildhorseCleveland National Forest1,483
Idaho (1)
AreaForestAcres
Bear CreekCaribou-Targhee National Forest118,582
Oregon (24)
AreaForestAcres
Drift CreekSiuslaw National Forest6,333
Drift CreekSiuslaw National Forest6,333
EagleMt. Hood National Forest16,841
EagleMt. Hood National Forest16,841
Hebo 1aSiuslaw National Forest13,930
Hebo 1aSiuslaw National Forest13,930
LarchMt. Hood National Forest12,961
LarchMt. Hood National Forest12,961
North KalmiopsisSiskiyou National Forests91,560
North KalmiopsisSiskiyou National Forests91,560
South KalmiopsisSiskiyou National Forests104,477
South KalmiopsisSiskiyou National Forests104,477
TahkenitchSiuslaw National Forest5,799
TahkenitchSiuslaw National Forest5,799
TahkenitchSiuslaw National Forest5,799
TenmileSiuslaw National Forest10,818
TenmileSiuslaw National Forest10,818
TenmileSiuslaw National Forest10,818
Umpqua SpitSiuslaw National Forest2,090
Umpqua SpitSiuslaw National Forest2,090
Umpqua SpitSiuslaw National Forest2,090
WoahinkSiuslaw National Forest5,309
WoahinkSiuslaw National Forest5,309
WoahinkSiuslaw National Forest5,309
South Dakota (1)
AreaForestAcres
Indian CreekBuffalo Gap National Grassland24,666
Texas (1)
AreaForestAcres
Big CreekNational Forests in Texas1,447
Washington (16)
AreaForestAcres
Bear CreekGifford Pinchot National Forest7,980
Bear CreekGifford Pinchot National Forest7,980
Green MountainOlympic National Forest4,617
Green MountainOlympic National Forest4,617
Jupiter RidgeOlympic National Forest10,148
Jupiter RidgeOlympic National Forest10,148
Madison CreekOlympic National Forest1,223
Madison CreekOlympic National Forest1,223
Mt. BaldyOlympic National Forest3,557
Mt. BaldyOlympic National Forest3,557
QuilceneOlympic National Forest18,656
QuilceneOlympic National Forest18,656
Rugged RidgeOlympic National Forest4,358
Rugged RidgeOlympic National Forest4,358
South QuinaultOlympic National Forest11,081
South QuinaultOlympic National Forest11,081
References (17)
  1. American Ornithologists' Union (AOU). 1983. Check-list of North American Birds, 6th edition. Allen Press, Inc., Lawrence, Kansas. 877 pp.
  2. American Ornithologists' Union (AOU). 1998. Check-list of North American birds. Seventh edition. American Ornithologists' Union, Washington, D.C. [as modified by subsequent supplements and corrections published in <i>The Auk</i>]. Also available online: http://www.aou.org/.
  3. BirdLife International. 2004b. Threatened birds of the world 2004. CD ROM. BirdLife International, Cambridge, UK.
  4. Gaston, A. J., and J. M. Hipfner. 2000. Thick-billed Murre (<i>Uria lomvia</i>). No. 497 IN A. Poole and F. Gill, editors, The birds of North America. The Birds of North America, Inc., Philadelphia, PA. 32pp.
  5. Gaston, A. J., et al. 1994. Population parameters of thick-billed murres at Coats Island, Northwest Territories, Canada. Condor 96:935-948.
  6. Harrison, C. 1978. A Field Guide to the Nests, Eggs and Nestlings of North American Birds. Collins, Cleveland, Ohio.
  7. Mostello, C. S., N. A. Palaia, and R. B. Clapp. 2000. Gray-backed Tern (Sterna lunata). No. 525 in A. Poole and F. Gill (editors). The birds of North America. The Birds of North America, Inc., Philadelphia, PA. 28 pp.
  8. Parker III, T. A., D. F. Stotz, and J. W. Fitzpatrick. 1996. Ecological and distributional databases for neotropical birds. The University of Chicago Press, Chicago.
  9. Pons, J. M., A. Hassanin, and P. A. Crochet. 2005. Phylogenetic relationships within the Laridae (Charadriiformes: Aves) inferred from mitochondrial markers. Molecular Phylogenetics and Evolution 37:686-699.
  10. Poole, A. F. and F. B. Gill. 1992. The birds of North America. The American Ornithologists' Union, Washington, D.C. and The Academy of Natural Sciences, Philadelphia, PA.
  11. Schreiber, E. A., R. W. Schreiber, and G. A. Schenk. 1996. Red-footed Booby (<i>Sula sula</i>). No. 241 in A. Poole and F. Gill, editors. The birds of North America. The Academy of Natural Sciences, Philadelphia, PA, and The Amerian Ornithologists' Union, Washington, DC. 24 pp.
  12. Spear, L. B. 1988. Dispersal patterns of western gulls from Southeast Farallon Island. Auk 105:128-141.
  13. Spear, L. B. 1993. Dynamics and effect of western gulls feeding in a colony of guillemots and Brandt's cormorants. J. Anim. Ecol. 62:399-414.
  14. Spear, L. B., D. G. Ainley, and R. P. Henderson. 1986. Post-fledging parental care in the western gull. Condor 88:194-199.
  15. Spendelow, J. A. and S. R. Patton. 1988. National Atlas of Coastal Waterbird Colonies in the Contiguous United States: 1976-1982. U.S. Fish and Wildlife Service, Biological Report 88(5). x + 326 pp.
  16. Terres, J. K. 1980. The Audubon Society encyclopedia of North American birds. Alfred A. Knopf, New York.
  17. The American Ornithologists' Union (AOU). Banks, R.C., R.T. Chesser, C. Cicero, J.L. Dunn, A.W. Kratter, I.J. Lovette, P.C. Rasmussen, J.V. Remsen, Jr., J.D. Rising, D.F. Stotz, and K. Winker. 2008. Forty-ninth supplement to the American Ornithologists' Union Check-list of North American Birds. The Auk 125(3):758-768.