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

Brown-headed Cowbird Population Trend in Virginia

All statesGeneralists

Brown-headed Cowbird in Virginia has edged down: down 23% on the route-weighted index since 1968.

-23%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 →
88Routes 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 VirginiaNotable 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 Virginia. See the full index history below.

Brown-headed Cowbird Population Forecast in Virginia

If the recent trend holds, Brown-headed Cowbird in Virginia is projected to fall about 20% by 2029 — from 5.6 in 2024 to a central estimate of 4.5 (95% range 2.6–6.3). A 5-year backtest shows a typical error of ±30.5%, with 60% of held-out values landing inside the 95% band.

-20%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 →
4.5Projected 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 →
2.6–6.395% 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 Virginia is projected to fall about 20% by 2029 — from 5.6 in 2024 to a central estimate of 4.5 (95% range 2.6–6.3). A 5-year backtest shows a typical error of ±30.5%, with 60% 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 →
20254.62.76.5
20264.52.76.4
20274.52.66.4
20284.52.66.4
20294.52.66.3

Brown-headed Cowbird Survey Routes in Virginia

Routes recording Brown-headed Cowbird in Virginia.
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 →
Chincoteag W2920221992
Backbay2419741966
Front Royal2220241993
Branchville2120241966
Newsoms1920241967
Hebron1920221981
Brandon1920241992
Quinby1620241966
Ringgold1420241985
Wylliesburg1420191971
Moran1320221996
Loft Mtn1320231993
Gloucester1120241992
Amherst1020241967
Big Island1020241968
Cornland1020141976
Port Royal920191977
Concord920241967
Mannboro920241967
Hall920231967
Pungo920241975
Taylorstown 2920242012
Pw Forest Pk920091992
Stanley820241966
Newville820241988

Brown-headed Cowbird Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontwashingtonwest-virginiawisconsinwyoming

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