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

Blue Grosbeak Population Trend in Kentucky

All statesGeneralists

Blue Grosbeak in Kentucky has surged: 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 →
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 →
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 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 28× 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 16% by 2029 — from 6.8 in 2024 to a central estimate of 7.8 (95% range 6.2–9.5). A 5-year backtest shows a typical error of ±14.7%, with 100% of held-out values landing inside the 95% band.

+16%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 →
7.8Projected 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 →
6.2–9.595% 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 →
±14.7%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 16% by 2029 — from 6.8 in 2024 to a central estimate of 7.8 (95% range 6.2–9.5). A 5-year backtest shows a typical error of ±14.7%, with 100% 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 →
20257.35.79.0
20267.55.99.1
20277.66.09.2
20287.76.19.3
20297.86.29.5

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
Lovelacevile2320241973
Hegira1720241988
Iron Bridge1419981966
Sulphur Lick1420241978
Demunbruns1420211968
Apex1320242005
Pleasurevill1320241981
Joy1320231981
Hodgenville 21320232008
Keysburg1120241968
Mckee1120242022
Johnsonville1120211978
Buena Vista1120171980
Cedar Grove1020241967
Monticello1020221992
Morganfield1020242022
Kings Mtn820241971
Merrimac820241972
Eastview820241970
Drakesboro819931976
Canton720241967
Sunnybrook720221974
Shiloh620241968
Hudson620241974

Blue Grosbeak Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradodelawarefloridageorgiaidahoillinoisindianaiowakansaslouisianamarylandminnesotamississippimissourimontananebraskanevadanew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniasouth-carolinasouth-dakotatennesseetexasutahvirginiawest-virginiawyoming

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