BirdAnalyst
BBS Route · California · BCR 32

Glenn Bird Survey Route

A standard 50-stop Breeding Bird Survey route. 104 species recorded across 44 survey years, still active.

104Species 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 →
44Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →
1971–2023Span
10Observers

Bird Species Found on California Glenn

Top 40 of 104 species by most recent count. Each links to its species trend.

Species recorded on the Glenn 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
Red-winged BlackbirdIcteridae7782023-43%1973
White-faced IbisThreskiornithidae205202125×1990
Brewer's BlackbirdIcteridae1852023+261%1973
House SparrowPasseridae123202340×1974
Bank SwallowHirundinidae1101997+8%1976
Cliff SwallowHirundinidae992023-42%1973
House FinchFringillidae97202317×1976
Tree SwallowHirundinidae702023+3%1977
KilldeerCharadriidae602023+159%1973
Mourning DoveColumbidae552023+60%1973
European StarlingSturnidae342023-46%1973
MallardAnatidae292023+23%1973
Great EgretArdeidae28202327×1973
Turkey VultureCathartidae25202327×1982
Western KingbirdTyrannidae222023-17%1973
Violet-green SwallowHirundinidae22199111×1985
Brown-headed CowbirdIcteridae212023-35%1977
Marsh WrenTroglodytidae202023+213%1976
Snowy EgretArdeidae172022+600%1981
American RobinTurdidae142023+371%1979
American BitternArdeidae132023+67%1973
Common GallinuleRallidae122009+700%1974
RedheadAnatidae102000n/an/a
American GoldfinchFringillidae82023+0%1977
Ash-throated FlycatcherTyrannidae82023+220%1979
Canada GooseAnatidae82017-73%1996
Great Blue HeronArdeidae72023+170%1973
American CootRallidae72015+0%1974
Barn SwallowHirundinidae72023-72%1973
Ring-billed GullLaridae72005+41%1995
Ring-necked PheasantPhasianidae62023-90%1973
Black PhoebeTyrannidae62023-8%1976
California TowheePasserellidae62021+167%1977
Black-necked StiltRecurvirostridae42015-68%1977
Green HeronArdeidae42009+133%1978
Tricolored BlackbirdIcteridae42019-51%1976
GadwallAnatidae42007+80%1990
California Scrub-JayCorvidae32019-13%1973
Savannah SparrowPasserellidae31971n/an/a
Northern MockingbirdMimidae32023-21%1973

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