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Species · Kansas · BBS 2025 Release · 1966–2024

Bell's Vireo Population Trend in Kansas

All statesForest birds

Bell's Vireo in Kansas has surged: up 189% on the route-weighted index since 1969.

+189%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 →
57Routes 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 Bell's Vireo 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 →

Bell's Vireo has surged in Kansas: up 189% on the route-weighted index since 1969.

Bell's Vireo Population Forecast in Kansas

If the recent trend holds, Bell's Vireo in Kansas is projected to fall about 23% by 2029 — from 2.8 in 2024 to a central estimate of 2.1 (95% range 1.5–2.8). A 5-year backtest shows a typical error of ±28.1%, with 40% of held-out values landing inside the 95% band.

-23%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 →
2.1Projected 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 →
1.5–2.895% 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 →
±28.1%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, Bell's Vireo in Kansas is projected to fall about 23% by 2029 — from 2.8 in 2024 to a central estimate of 2.1 (95% range 1.5–2.8). A 5-year backtest shows a typical error of ±28.1%, with 40% 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 →
20252.01.32.7
20262.11.42.7
20272.11.42.8
20282.11.42.8
20292.11.52.8

Bell's Vireo Survey Routes in Kansas

Routes recording Bell's Vireo 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 →
Kanopolis1820241970
Trading Post1220242000
Lincolnville1120242002
Thrall519671967
St John520191968
Minneapolis520191967
Jamestown520242000
Solomon520191982
Dover420221968
Wreford420241967
Hanover420231969
Humboldt320221984
Albert320241968
Hollenberg320231969
Morehead320242001
Susank320222016
Severance320242000
Melrose220181967
Jewell 2220242009
Olathe220211968
Barclay220131967
Ellinor220241972
Chapman219811968
Buckeye220231967
Grantville220221968

Bell's Vireo Population Trend in Other States

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