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Species · Kentucky · BBS 2026 Release · 1966–2025

Blue Grosbeak Population Trend in Kentucky

All statesForest birds

Blue Grosbeak in Kentucky has surged: up 29× on the route-weighted index since 1968.

29×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 →
56Routes 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 KentuckyNotable 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 Kentucky: up 29× on the route-weighted index since 1968.

Blue Grosbeak Population Forecast in Kentucky

If the recent trend holds, Blue Grosbeak in Kentucky is projected to rise about 19% by 2030 — from 6.6 in 2025 to a central estimate of 7.9 (95% range 6.3–9.5). A 5-year backtest shows a typical error of ±15.2%, with 100% of held-out values landing inside the 95% band.

+19%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 →
7.9Projected 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 →
6.3–9.595% 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 →
±15.2%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 Kentucky is projected to rise about 19% by 2030 — from 6.6 in 2025 to a central estimate of 7.9 (95% range 6.3–9.5). A 5-year backtest shows a typical error of ±15.2%, 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 →
20267.45.89.0
20277.55.99.2
20287.76.09.3
20297.86.29.4
20307.96.39.5

Blue Grosbeak Survey Routes in Kentucky

Routes recording Blue Grosbeak in Kentucky.
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 →
Bays Fork2420191999
Keysburg1920251968
Hegira1720241988
Mckee1620252022
Iron Bridge1419981966
Sulphur Lick1420241978
Demunbruns1420211968
Joy1320231981
Hodgenville 21320232008
Johnsonville1120211978
Buena Vista1120171980
Monticello1020221992
Lovelacevile920251973
Cedar Grove820251967
Pleasurevill820251981
Kings Mtn820251971
Hustonville820251984
Merrimac820241972
Hudson820251974
Eastview820251970
Drakesboro819931976
Porter820251983
Sewell Shop820251987
Sunnybrook720221974
Mcbrayer720251983

Blue Grosbeak Population Trend in Other States

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