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

Brown-headed Cowbird Population Trend in Ohio

All statesGeneralists

Brown-headed Cowbird in Ohio has held roughly steady: down 2% on the route-weighted index since 1968.

-2%Since 1968TrendPercent 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 →
89Routes 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 →
58YearsYears 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 OhioNotable 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 Ohio. See the full index history below.

Brown-headed Cowbird Population Forecast in Ohio

If the recent trend holds, Brown-headed Cowbird in Ohio is projected to rise about 15% by 2029 — from 11 in 2024 to a central estimate of 12 (95% range 9.0–15). A 5-year backtest shows a typical error of ±10.4%, with 100% of held-out values landing inside the 95% band.

+15%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 →
9.0–1595% 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 →
±10.4%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 Ohio is projected to rise about 15% by 2029 — from 11 in 2024 to a central estimate of 12 (95% range 9.0–15). A 5-year backtest shows a typical error of ±10.4%, with 100% of held-out values landing inside the 95% band.19662029
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 →
2025128.815
2026128.915
2027128.915
2028128.915
2029129.015

Brown-headed Cowbird Survey Routes in Ohio

Routes recording Brown-headed Cowbird in Ohio.
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 →
Stonecreek3720241996
Newcomerstwn2919951966
Harveysburg2919961966
Dresden2820241966
N Baltimore2620191966
Botkins2320191992
Bismark2119951967
Kunkle2020241992
Valley City2020241995
Ashley1920181988
London1820121997
Dunlap1719881966
Marion 21620242024
W Carrollton1620151989
Maysville1520121992
New Somerset1519931966
Cuba1520241992
Vickery1520241996
Enon1520241984
Kalida1420191966
Coal Run1419921966
Pittsfield1320241992
Kenton1320241966
Marion1320231966
Smithfield1320241966

Brown-headed Cowbird Population Trend in Other States

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

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