BirdAnalyst
BBS Route · California · BCR 32

Glenn Bird Survey Route

A standard 50-stop Breeding Bird Survey route. 104 species recorded across 45 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 →
45Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →
1971–2025Span
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 BlackbirdIcteridae11022025-37%1973
Bank SwallowHirundinidae1101997+8%1976
European StarlingSturnidae1002025+13%1973
Cliff SwallowHirundinidae912025-27%1973
Mourning DoveColumbidae862025+73%1973
House SparrowPasseridae63202528×1974
Great EgretArdeidae62202526×1973
Tree SwallowHirundinidae612025+46%1977
House FinchFringillidae51202516×1976
Barn SwallowHirundinidae322025+3%1973
Tricolored BlackbirdIcteridae312025-34%1976
KilldeerCharadriidae302025+167%1973
Turkey VultureCathartidae30202526×1982
MallardAnatidae262025+35%1973
Violet-green SwallowHirundinidae22199111×1985
Yellow-billed MagpieCorvidae172025-56%1973
American RobinTurdidae142023+371%1979
Marsh WrenTroglodytidae132025+127%1976
Common GallinuleRallidae122009+700%1974
Brewer's BlackbirdIcteridae112025+113%1973
RedheadAnatidae102000n/an/a
American BitternArdeidae92025+92%1973
Canada GooseAnatidae82017-73%1996
American CootRallidae72015+0%1974
Snowy EgretArdeidae72025+443%1981
Brown-headed CowbirdIcteridae72025-42%1977
Ring-billed GullLaridae72005+41%1995
California TowheePasserellidae62021+167%1977
Western KingbirdTyrannidae52025-37%1973
Black-necked StiltRecurvirostridae42015-68%1977
Green HeronArdeidae42009+133%1978
White-faced IbisThreskiornithidae4202522×1990
Great Blue HeronArdeidae32025+70%1973
California Scrub-JayCorvidae32019-13%1973
Savannah SparrowPasserellidae31971n/an/a
Northern MockingbirdMimidae32023-21%1973
Red-tailed HawkAccipitridae32025+325%1975
SoraRallidae31975+50%1973
Rock PigeonColumbidae32021-73%1975
American GoldfinchFringillidae32025-17%1977

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14. A route is a sample, not a census.