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Species · Oklahoma · BBS 2025 Release · 1966–2024

Brown-headed Cowbird Population Trend in Oklahoma

All statesGeneralists

Brown-headed Cowbird in Oklahoma has fallen sharply: down 57% on the route-weighted index since 1969.

-57%Since 1969TrendPercent 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 →
71Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Brown-headed Cowbird Trends in OklahomaNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

long arc declinecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Brown-headed Cowbird has fallen sharply in Oklahoma: down 57% on the route-weighted index since 1969.

Brown-headed Cowbird Population Forecast in Oklahoma

If the recent trend holds, Brown-headed Cowbird in Oklahoma is projected to fall about 10% by 2029 — from 14 in 2024 to a central estimate of 12 (95% range 6.2–19). A 5-year backtest shows a typical error of ±12.2%, with 100% of held-out values landing inside the 95% band.

-10%Change by 2029TrendPercent 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 →
12Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
6.2–1995% range95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
±12.2%Backtest errorBacktest errorTypical error when we hold out the most recent years, forecast them, and compare to what actually happened. Lower means a more trustworthy projection.Full methodology →
If the recent trend holds, Brown-headed Cowbird in Oklahoma is projected to fall about 10% by 2029 — from 14 in 2024 to a central estimate of 12 (95% range 6.2–19). A 5-year backtest shows a typical error of ±12.2%, with 100% of held-out values landing inside the 95% band.19672029
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →95% low95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →95% high95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
2025147.320
2026137.020
2027136.719
2028136.519
2029126.219

Brown-headed Cowbird Survey Routes in Oklahoma

Routes recording Brown-headed Cowbird in Oklahoma.
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 →
Hunter6020241992
Verden4820171967
Colcord4820221992
Matoy4620001992
Goodwater4020211992
Jet3920241992
Wakita3620161967
Colony3519951995
Pocola3520161992
Mill Creek3420181967
Keetonville3420221992
Skiatook3320191982
Heyburn3220241992
Loco3119851967
Wainwright3120131992
Ft Sill East3119941994
Ardmore2920091967
Tatums2720241992
Cooperton2120241992
Hollis2120241993
Cashion2120241992
Ft Sill West2019941994
Eagle City1920101968
Duncan1920241987
Canadian1820171967

Brown-headed Cowbird Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.