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

Blue Grosbeak Population Trend in Alabama

All statesGeneralists

Blue Grosbeak in Alabama has edged up: up 19% on the route-weighted index since 1968.

+19%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 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 25% by 2029 — from 11 in 2024 to a central estimate of 8.0 (95% range 5.9–10). A 5-year backtest shows a typical error of ±8.4%, with 80% 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 →
8.0Projected 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 →
5.9–1095% 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 →
±8.4%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 25% by 2029 — from 11 in 2024 to a central estimate of 8.0 (95% range 5.9–10). A 5-year backtest shows a typical error of ±8.4%, 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 →
20257.95.89.9
20267.95.89.9
20277.95.810.0
20287.95.910
20298.05.910

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
Cottonton2720241966
Talladega2720241996
Grangeburg2520241966
Newton2220241966
Epes2220241980
Calebee2120241994
Elamville2020241984
Whitehall1820241983
Wheeler Dam1820231993
Stevenson1820241996
Brundidge1720211966
Sprague1620241966
Madrid1620231994
Georgetown1620241994
Eufaula1620241996
Greensport1520241966
Warrior Std1520241966
Fairview1520241989
Childersburg1519991985
Bay Minette1520241998
Liberty City1420111979
Lakeview1320241999
Jena1220241981
Woodville1220241994

Blue Grosbeak Population Trend in Other States

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