BirdAnalyst
Species · Virginia · BBS 2026 Release · 1966–2025

Blue Grosbeak Population Trend in Virginia

All statesForest birds

Blue Grosbeak in Virginia has surged: up 108% on the route-weighted index since 1968.

+108%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 →
75Routes 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 →
59YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Blue Grosbeak 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 →

long arc increasecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Blue Grosbeak has surged in Virginia: up 108% on the route-weighted index since 1968.

Blue Grosbeak Population Forecast in Virginia

If the recent trend holds, Blue Grosbeak in Virginia is projected to stay roughly flat through 2030, near 5.4 (95% range 3.3–7.6). A 5-year backtest shows a typical error of ±12.5%, with 100% of held-out values landing inside the 95% band.

+1%Change by 2030TrendPercent 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 →
5.4Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
3.3–7.695% 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 →
±12.5%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, Blue Grosbeak in Virginia is projected to stay roughly flat through 2030, near 5.4 (95% range 3.3–7.6). A 5-year backtest shows a typical error of ±12.5%, with 100% of held-out values landing inside the 95% band.19662030
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 →
20265.43.27.5
20275.43.27.5
20285.43.27.5
20295.43.27.5
20305.43.37.6

Blue Grosbeak Survey Routes in Virginia

Routes recording Blue Grosbeak 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 →
Newville3120241988
Quinby2920251966
Finchley2820211994
Newsoms2420241971
Brodnax2320251973
Chincoteag W2320241992
Ringgold2020251976
Brandon1920251992
Surry1820251977
Branchville1820241966
Waverly1619871967
Church Road1620251966
White Stone1520251967
Pungo1520251975
Gladys1520251994
Concord1320241967
Mannboro1320251967
Cape Charles1320181992
Cornland1120141975
Appomattox1020241995
Truhart920241996
Gloucester820251992
Carters Brdg 2820252015
Clinchport719781974
Irisburg720251976

Blue Grosbeak Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradodelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamarylandminnesotamississippimissourimontananebraskanevadanew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniasouth-carolinasouth-dakotatennesseetexasutahwest-virginiawyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.