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BBS Route · California · BCR 32

Oilfields Bird Survey Route

A standard 50-stop Breeding Bird Survey route. 55 species recorded across 19 survey years, still active.

55Species RecordedSpecies recordedDistinct species detected on standard-protocol BBS runs here across all years on record — a measure of survey breadth, not a complete checklist.Full methodology →
19Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →
1968–2013Span
8Observers

Bird Species Found on California Oilfields

Top 40 of 55 species by most recent count. Each links to its species trend.

Species recorded on the Oilfields route.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →History
Brewer's BlackbirdIcteridae1902013+31%1970
Cliff SwallowHirundinidae892013-59%1970
Northern Rough-winged SwallowHirundinidae772005n/an/a
Mourning DoveColumbidae702013+29%1970
House SparrowPasseridae572013-68%1970
Tricolored BlackbirdIcteridae561976+287%1969
Common RavenCorvidae452013+202%1997
American AvocetRecurvirostridae361998+350%1970
House FinchFringillidae272013+350%1970
Red-winged BlackbirdIcteridae162013-88%1970
Burrowing OwlStrigidae151981+380%1971
American CrowCorvidae142013+562%1970
Black-necked StiltRecurvirostridae121998-65%1976
Barn SwallowHirundinidae122013+467%1975
Lawrence's GoldfinchFringillidae12200012×1981
American RobinTurdidae112005+59%1975
Rock PigeonColumbidae102013+200%1976
Brown-headed CowbirdIcteridae102005-73%1974
Horned LarkAlaudidae92012-86%1970
Northern MockingbirdMimidae82005+100%1971
Savannah SparrowPasserellidae82005+175%1998
Northern HarrierAccipitridae61999+86%1981
KilldeerCharadriidae52013+90%1972
Ring-necked PheasantPhasianidae41981-41%1970
Western MeadowlarkIcteridae42013-69%1970
California QuailOdontophoridae42000-69%1971
Lesser GoldfinchFringillidae42005+83%1980
MallardAnatidae42012+33%1981
Western KingbirdTyrannidae32013+155%1970
Loggerhead ShrikeLaniidae32005+17%1975
Black PhoebeTyrannidae31998n/an/a
Tree SwallowHirundinidae32005n/an/a
American KestrelFalconidae22005+0%1972
Anna's HummingbirdTrochilidae22005+0%1980
Northern PintailAnatidae21975+0%1973
Bullock's OrioleIcteridae21981+0%1974
Ruddy DuckAnatidae21976n/an/a
American GoldfinchFringillidae21978n/an/a
American BitternArdeidae11968n/an/a
Ash-throated FlycatcherTyrannidae12000+0%1968

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22. A route is a sample, not a census.