BirdAnalyst
Species · Missouri · BBS 2025 Release · 1966–2024

Brown-headed Cowbird Population Trend in Missouri

All statesGeneralists

Brown-headed Cowbird in Missouri has edged up: up 25% on the route-weighted index since 1969.

+25%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 →
94Routes 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 MissouriNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

No notable trend signals for Brown-headed Cowbird in Missouri. See the full index history below.

Brown-headed Cowbird Population Forecast in Missouri

If the recent trend holds, Brown-headed Cowbird in Missouri is projected to fall about 10% by 2029 — from 23 in 2024 to a central estimate of 21 (95% range 14–28). A 5-year backtest shows a typical error of ±8.8%, 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 →
21Projected 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 →
14–2895% 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 →
±8.8%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 Missouri is projected to fall about 10% by 2029 — from 23 in 2024 to a central estimate of 21 (95% range 14–28). A 5-year backtest shows a typical error of ±8.8%, 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 →
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Brown-headed Cowbird Survey Routes in Missouri

Routes recording Brown-headed Cowbird in Missouri.
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 →
Norborne9820232006
Milford6620242015
Deventer5720241967
Hayti5720212016
Eugene5620242013
Syracuse5320241969
West Plains5320242014
Madison4720241971
Kahoka24720242002
Rensselaer4520241971
Kearney4320241994
Osage Beach4120241997
Rueter 24120242023
Warren3919831967
New Point3920241994
Sticklervill3820241970
Gerald3420242013
Blodgett3420242013
Whitewater3220241996
Ohio3120241972
Hamilton3119851972
Clementine 23120072005
Palace3120242013
Peace Valley3020241975
Sni Mills3019901967

Brown-headed Cowbird Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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