BirdAnalyst
Species · Kansas · BBS 2026 Release · 1966–2025

Brown Thrasher Population Trend in Kansas

All statesForest birds

Brown Thrasher in Kansas has declined: down 37% on the route-weighted index since 1969.

-37%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 →
67Routes 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 Brown Thrasher 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 →

No notable trend signals for Brown Thrasher in Kansas. See the full index history below.

Brown Thrasher Population Forecast in Kansas

If the recent trend holds, Brown Thrasher in Kansas is projected to fall about 18% by 2030 — from 6.8 in 2025 to a central estimate of 5.5 (95% range 3.4–7.7). A 5-year backtest shows a typical error of ±17.1%, with 100% of held-out values landing inside the 95% band.

-18%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 →
5.5Projected 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 →
3.4–7.795% 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 →
±17.1%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, Brown Thrasher in Kansas is projected to fall about 18% by 2030 — from 6.8 in 2025 to a central estimate of 5.5 (95% range 3.4–7.7). A 5-year backtest shows a typical error of ±17.1%, with 100% of held-out values landing inside the 95% band.19672030
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 →
20265.93.88.0
20275.83.77.9
20285.73.67.8
20295.63.57.8
20305.53.47.7

Brown Thrasher Survey Routes in Kansas

Routes recording Brown Thrasher 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 →
Phillipsburg2820251967
Hanover2220251969
Jewell2020051967
Hollenberg1920251969
Beloit1920032000
Covert1720251967
Grantville1520221967
Lincolnville1520242002
Chapman1419811967
Kanopolis1320251967
Beloit 21320182005
Logan1120251967
Trading Post920252000
St John820191967
Minneapolis820191967
Jewell 2820252006
Solomon820251982
Galesburg720251967
Goessel720252000
Severance720252000
Damar720162000
Gray620191967
Pittsburg620212000
Ash Valley620192000
Bucyrus520252022

Brown Thrasher Population Trend in Other States

alabamaarkansascoloradoconnecticutdelawarefloridageorgiaillinoisindianaiowakentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsinwyoming

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