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

Blue Grosbeak Population Trend in Alabama

All statesForest birds

Blue Grosbeak in Alabama has increased: up 28% on the route-weighted index since 1968.

+28%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 →
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 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 Blue Grosbeak in Alabama. See the full index history below.

Blue Grosbeak Population Forecast in Alabama

If the recent trend holds, Blue Grosbeak in Alabama is projected to fall about 15% by 2030 — from 9.6 in 2025 to a central estimate of 8.1 (95% range 6.0–10). A 5-year backtest shows a typical error of ±12%, with 60% of held-out values landing inside the 95% band.

-15%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 →
8.1Projected 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 →
6.0–1095% 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%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 Alabama is projected to fall about 15% by 2030 — from 9.6 in 2025 to a central estimate of 8.1 (95% range 6.0–10). A 5-year backtest shows a typical error of ±12%, with 60% 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 →
20268.05.910
20278.05.910
20288.16.010
20298.16.010
20308.16.010

Blue Grosbeak Survey Routes in Alabama

Routes recording Blue Grosbeak 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 →
Rock Chapel4620241995
Harrell2820251968
Grangeburg2520241966
Elamville2320251984
Talladega2320251996
Newton2220241966
Epes2220241980
Warrior Std2020251966
Brantley1820251966
Calebee1820251994
Stevenson1820241996
Brundidge1720211966
Whitehall1720251983
Wheeler Dam1720251993
St. Elmo1720251998
Mclellan1620251966
Madrid1620231994
Autaugaville1620251996
Eufaula1620241996
Childersburg1519991985
Brooksville1520251984
Millerville1420251966
Liberty City1420111979
Greensport1320251966
Cottonton1320251966

Blue Grosbeak Population Trend in Other States

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