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

Brown-headed Cowbird Population Trend in Indiana

All statesGeneralists

Brown-headed Cowbird in Indiana has held roughly steady: up 8% on the route-weighted index since 1968.

+8%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 →
69Routes 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 IndianaNotable 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 Indiana. See the full index history below.

Brown-headed Cowbird Population Forecast in Indiana

If the recent trend holds, Brown-headed Cowbird in Indiana is projected to rise about 40% by 2029 — from 14 in 2024 to a central estimate of 20 (95% range 14–26). A 5-year backtest shows a typical error of ±30.5%, with 80% of held-out values landing inside the 95% band.

+40%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 →
20Projected 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 →
14–2695% 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 →
±30.5%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 Indiana is projected to rise about 40% by 2029 — from 14 in 2024 to a central estimate of 20 (95% range 14–26). A 5-year backtest shows a typical error of ±30.5%, with 80% 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 →
2025191325
2026201426
2027201426
2028201426
2029201426

Brown-headed Cowbird Survey Routes in Indiana

Routes recording Brown-headed Cowbird in Indiana.
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 →
Newberry5520241999
Packertown5020041967
W Lafayette4020241981
Thorntown3820241982
Jamestown3820241986
Celestine3820241979
Kewanna3020221981
Ellis3020241966
Maplewood3020212000
Evansville2820221966
Middletown2420241966
Anderson2420242000
Sexton2320241981
Indian Spgs2320241982
Frankfort2320221999
Plainfield2319991999
Georgia2320241999
New Phila2220241982
Wallace2220241999
Hebron2120221966
Muncie2119971981
Kokomo2120241993
Rensselaer1920241999
New Castle1920242002
Galveston1720241981

Brown-headed Cowbird Population Trend in Other States

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

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