California Gull - Larus californicus
FWP Conservation Tier
Medium-sized white-headed gull; male slightly larger than female. Definitive plumage, combination of dark gray mantle, yellow green legs, and black and red spots on gonys (enlarged part of lower mandible where left and right halves come together) distinguish this species from all other gulls in its summer range.
Summary of Observations Submitted for Montana
Number of Observations:
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Map Help and Descriptions
(direct evidence "B")
(indirect evidence "b")
No evidence of Breeding
(regular observations "W")
(at least one obs. "w")
(Records associated with a range of dates are excluded from time charts)
In the Bozeman area, normal migration periods are March 25 to May 15 and again during August 1 to November 25, with peaks April 15 and September 25 (Skaar 1969). Adult California Gulls that were marked on the breeding colony at Freezeout Lake were later reobserved on the Pacific coast from Vancouver, Canada to Baja California, Mexico (Rothweiler 1960).
In the Bozeman area, the California Gull prefers larger lakes, but also occurs on ponds and rivers, especially in spring and fall (Skaar 1969). In Montana, colonies are typically located on islands (Rothweiler 1960). Nests are located either among dried vegetation or on bare ground (Rothweiler 1960)
Ecological Systems Associated with this Species
- Details on Creation and Suggested Uses and Limitations
How Associations Were Made
We associated the use and habitat quality (high, medium, or low) of each of the 82 ecological systems mapped in Montana for
vertebrate animal species that regularly breed, overwinter, or migrate through the state by:
- Using personal observations and reviewing literature that summarize the breeding, overwintering, or migratory habitat requirements of each species (Dobkin 1992, Hart et al. 1998, Hutto and Young 1999, Maxell 2000, Foresman 2001, Adams 2003, and Werner et al. 2004);
- Evaluating structural characteristics and distribution of each ecological system relative to the species’ range and habitat requirements;
- Examining the observation records for each species in the state-wide point database associated with each ecological system;
- Calculating the percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system to get a measure of “observations versus availability of habitat”.
Species that breed in Montana were only evaluated for breeding habitat use, species that only overwinter in Montana were only evaluated for overwintering habitat use, and species that only migrate through Montana were only evaluated for migratory habitat use.
In general, species were associated as using an ecological system if structural characteristics of used habitat documented in the literature were present in the ecological system or large numbers of point observations were associated with the ecological system.
However, species were not associated with an ecological system if there was no support in the literature for use of structural characteristics in an ecological system, even if
point observations were associated with that system.
High, medium, and low habitat quality was assigned based on the degree to which the structural characteristics of an ecological system matched the preferred structural habitat characteristics for each species in the literature.
The percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system was also used to guide assignments of habitat quality.
If you have any questions or comments on species associations with ecological systems, please contact Bryce Maxell at email@example.com
or (406) 444-3655.
Suggested Uses and Limitations
Species associations with ecological systems should be used to generate potential lists of species that may occupy broader landscapes for the purposes of landscape-level planning.
These potential lists of species should not be used in place of documented occurrences of species (this information can be requested at: http://mtnhp.org/requests/default.asp
) or systematic surveys for species and evaluations of habitat at a local site level by trained biologists.
Users of this information should be aware that the land cover data used to generate species associations is based on imagery from the late 1990s and early 2000s and was only intended to be used at broader landscape scales.
Land cover mapping accuracy is particularly problematic when the systems occur as small patches or where the land cover types have been altered over the past decade.
Thus, particular caution should be used when using the associations in assessments of smaller areas (e.g., evaluations of public land survey sections).
Finally, although a species may be associated with a particular ecological system within its known geographic range, portions of that ecological system may occur outside of the species’ known geographic range.
- Adams, R.A. 2003. Bats of the Rocky Mountain West; natural history, ecology, and conservation. Boulder, CO: University Press of Colorado. 289 p.
- Dobkin, D. S. 1992. Neotropical migrant land birds in the Northern Rockies and Great Plains. USDA Forest Service, Northern Region. Publication No. R1-93-34. Missoula, MT.
- Foresman, K.R. 2001. The wild mammals of Montana. Special Publication No. 12. Lawrence, KS: The American Society of Mammalogists. 278 p.
- Hart, M.M., W.A. Williams, P.C. Thornton, K.P. McLaughlin, C.M. Tobalske, B.A. Maxell, D.P. Hendricks, C.R. Peterson, and R.L. Redmond. 1998. Montana atlas of terrestrial vertebrates. Montana Cooperative Wildlife Research Unit, University of Montana, Missoula, MT. 1302 p.
- Hutto, R.L. and J.S. Young. 1999. Habitat relationships of landbirds in the Northern Region, USDA Forest Service, Rocky Mountain Research Station RMRS-GTR-32. 72 p.
- Maxell, B.A. 2000. Management of Montana’s amphibians: a review of factors that may present a risk to population viability and accounts on the identification, distribution, taxonomy, habitat use, natural history, and the status and conservation of individual species. Report to U.S. Forest Service Region 1. Missoula, MT: Wildlife Biology Program, University of Montana. 161 p.
- Werner, J.K., B.A. Maxell, P. Hendricks, and D. Flath. 2004. Amphibians and reptiles of Montana. Missoula, MT: Mountain Press Publishing Company. 262 p.
At Freezeout Lake, stomach contents included insects, oligochaetes, crustaceans, amphibians and birds, and plant material believed to be ingested incidentally to consuming animals (Rothweiler 1960).
At Freezeout Lake, in nesting colonies with Ring-billed Gulls, the nesting habitat is segregated with respect to vegetative characteristics, and food niches are separated by different foraging distances (Baird 1976).
At Freezeout Lake nests varied in shape from depressions in the ground to constructed mounds; they were located 2 to 75 feet apart (Rothweiler 1960).
- Additional ReferencesLegend: View WorldCat Record View Online Publication
Do you know of a citation we're missing?
- American Ornithologists' Union. 1998. Check-list of North American birds. 7th edition. American Ornithologists' Union, Washington, D.C. 829 pp.
- Baird, P. 1976. Comparative ecology of California and ring-billed gulls (Larus californicus and L. delawarensis). Ph.D. Thesis, University of Montana, Missoula.
- Baird, P. A. 1976. Comparative ecology of California and ring-billed gulls. Ph.D dissertation. University of Montana, Missoula.
- Conover, M., 1983. Recent changes in Ring-billed and California Gull populations in the western United States. Wilson Bull. 95(3):362-383.
- Ehrlich, P., D. Dobkin, and D. Wheye. 1988. The birder’s handbook: a field guide to the natural history of North American birds. Simon and Schuster Inc. New York. 785 pp.
- Findholt, S.L. 1986l. Status and distribution of California Gulls (Larus californicus) nesting colonies in Wyoming (USA). Great Basin Nat. 46(1): 128-133.
- Godfrey, W. Earl. 1966. The birds of Canada. National Museums of Canada, Ottawa. 428 pp.
- Golden Sunlight Mines, Inc., Whitehall, MT., 2000, Golden Sunlight Mines, Inc., Annual Permit Reports.
- Jehl, J. R., Jr., and S. A. Mahoney. 1987. The roles of thermal environment and predation in habitat choice in the California gull. Condor 89:850-862.
- Johnsgard, P. A. 1992. Birds of the Rocky Mountains with particular reference to national parks in the northern Rocky Mountain region. Lincoln: University of Nebraska Press. xi + 504 pp.
- Land & Water Consulting, Inc., Missoula, MT., 2002, Montana Dept. of Transportation Wetland Mitigation Monitoring Report, Year 2002: Cow Coulee, Townsend, Montana. Proj. No. 130091.013. February 2003. In 2002 Wetland Mitigation Monitoring Reports, Vol. I.
- Lenard, S., J. Carlson, J. Ellis, C. Jones, and C. Tilly. 2003. P. D. Skaar's Montana Bird Distribution, 6th Edition. Montana Audubon: Helena, MT, 144 pp.
- Montana Bird Distribution Committee. 2012. P.D. Skaar's Montana bird distribution. 7th Edition. Montana Audubon, Helena, Montana. 208 pp. + foldout map.
- Salt, W.R. and J.R. Salt. 1976. The birds of Alberta. Hurtig Publishers, Edmonton, Alberta. xv + 498 pp.
- Stewart, R.E. 1975. Breeding birds of North Dakota. Tri-College Center for Environmental Studies, Fargo, North Dakota. 295 pp.
- U.S. Forest Service. 1991. Forest and rangeland birds of the United States: Natural history and habitat use. U.S. Department of Agriculture, Forest Service Agricultural Handbook 688. 625 pages.
- Vermeer, K. 1970. Breeding biology of California and Ring-billed Gulls. Can. Wildl. Serv. Rept. 12: 52 pp.
- Winkler, David W. 1996. California Gull (Larus californicus). Species Account Number 259. The Birds of North America Online (A. Poole, Ed.). Ithaca, NY: Cornell Laboratory of Ornithology; Retrieved 3/25/2008 from The Birds of North America Online database