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

Blue Grosbeak Population Trend in Kansas

All statesGeneralists

Blue Grosbeak in Kansas has surged: up 181% on the route-weighted index since 1969.

+181%Since 1969TrendPercent 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 →
65Routes 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 →
57YearsYears 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 KansasNotable 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 Kansas: up 181% on the route-weighted index since 1969.

Blue Grosbeak Population Forecast in Kansas

If the recent trend holds, Blue Grosbeak in Kansas is projected to fall about 32% by 2029 — from 4.8 in 2024 to a central estimate of 3.3 (95% range 2.2–4.5). A 5-year backtest shows a typical error of ±35.8%, with 20% of held-out values landing inside the 95% band.

-32%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 →
3.3Projected 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 →
2.2–4.595% 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 →
±35.8%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 Kansas is projected to fall about 32% by 2029 — from 4.8 in 2024 to a central estimate of 3.3 (95% range 2.2–4.5). A 5-year backtest shows a typical error of ±35.8%, with 20% of held-out values landing inside the 95% band.19672029
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 →
20253.12.04.3
20263.22.04.3
20273.22.14.4
20283.32.14.4
20293.32.24.5

Blue Grosbeak Survey Routes in Kansas

Routes recording Blue Grosbeak in Kansas.
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 →
Lincolnville1620242002
Kanopolis1320241967
Bucyrus1220242022
Severance1120242000
Reece1020242000
Humboldt920221977
Ashland820211973
Wallace820221969
Rexford820242000
Galesburg720241990
Trading Post720242000
Olathe620211967
Covert620241968
Melrose520231976
Dover520221968
Ellinor520231967
Hanover520231988
Seneca520221980
Berwet520242003
Plymell520242000
Thrall419671967
Lakin420221970
Wreford420241967
Gove420221976
Pittsburg420182002

Blue Grosbeak Population Trend in Other States

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

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