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

Brown-headed Cowbird Population Trend in Alabama

All statesGeneralists

Brown-headed Cowbird in Alabama has held roughly steady: up 6% on the route-weighted index since 1968.

+6%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 →
108Routes 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 AlabamaNotable 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 Alabama. See the full index history below.

Brown-headed Cowbird Population Forecast in Alabama

If the recent trend holds, Brown-headed Cowbird in Alabama is projected to fall about 25% by 2029 — from 9.2 in 2024 to a central estimate of 6.9 (95% range 4.1–9.7). A 5-year backtest shows a typical error of ±16.5%, with 100% of held-out values landing inside the 95% band.

-25%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 →
6.9Projected 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 →
4.1–9.795% 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 →
±16.5%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 Alabama is projected to fall about 25% by 2029 — from 9.2 in 2024 to a central estimate of 6.9 (95% range 4.1–9.7). A 5-year backtest shows a typical error of ±16.5%, 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 →
20257.14.29.9
20267.04.29.9
20277.04.29.8
20286.94.19.8
20296.94.19.7

Brown-headed Cowbird Survey Routes in Alabama

Routes recording Brown-headed Cowbird in Alabama.
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 →
Elberta5120221986
Stevenson3820241996
Rock Chapel2520241995
Elkmont2420241990
Newton2120241966
Epes2020241980
St Florian1920241967
Cottonton1920241966
Greensboro1620241966
Valhermoso Spgs1520101966
Mentone1520231993
Wheeler Dam1520231993
Valhermoso Spg 21520142014
Nixburg 21520242000
Eufaula1520241996
Millerville1420241967
Sprague1420241966
Billingsley1420221966
Brantley1420241966
Alabama Pt1420031966
Birmingham1419951969
Calebee1420241993
Carter Grove1420232003
Blocton1320241969
Childersburg1319991985

Brown-headed Cowbird Population Trend in Other States

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

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