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Species · Missouri · BBS 2026 Release · 1966–2025

Brown Thrasher Population Trend in Missouri

All statesForest birds

Brown Thrasher in Missouri has fallen sharply: down 62% on the route-weighted index since 1969.

-62%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 →
93Routes 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 MissouriNotable 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 declinecomputed 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 →

Brown Thrasher has fallen sharply in Missouri: down 61% on the route-weighted index since 1969.

Brown Thrasher Population Forecast in Missouri

If the recent trend holds, Brown Thrasher in Missouri is projected to fall about 20% by 2030 — from 3.9 in 2025 to a central estimate of 3.1 (95% range 0.48–5.7). A 5-year backtest shows a typical error of ±13.6%, with 100% of held-out values landing inside the 95% band.

-20%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 →
3.1Projected 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 →
0.48–5.795% 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 →
±13.6%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 Missouri is projected to fall about 20% by 2030 — from 3.9 in 2025 to a central estimate of 3.1 (95% range 0.48–5.7). A 5-year backtest shows a typical error of ±13.6%, 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 →
20263.60.936.2
20273.40.826.1
20283.30.716.0
20293.20.595.8
20303.10.485.7

Brown Thrasher Survey Routes in Missouri

Routes recording Brown Thrasher in Missouri.
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 →
Huntsville1320251967
Mcfall1320251994
Norborne1320232006
Stet1219951972
Akers1120251967
Bolckow1119921967
Emden1120242017
Ohio1020251972
Rensselaer1020251971
Hamilton1019851972
Whitewater1020251996
Madison920241971
Trenton920251967
Harrisonville920252025
Cascade820251967
Frazier820241967
Gildehouse819891978
Frankford820251985
Cameron820251986
Doe Run820242016
Barks720251994
Marshfield720231994
Sedalia720251991
Kingsville720251992
New Hampton720252014

Brown Thrasher Population Trend in Other States

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

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