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

Brown Thrasher Population Trend in Missouri

All statesGeneralists

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 →
92Routes 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 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 stay roughly flat through 2029, near 3.2 (95% range 0.55–5.8). A 5-year backtest shows a typical error of ±14.8%, with 100% of held-out values landing inside the 95% band.

-8%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 →
3.2Projected 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 →
0.55–5.895% 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 →
±14.8%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, Brown Thrasher in Missouri is projected to stay roughly flat through 2029, near 3.2 (95% range 0.55–5.8). A 5-year backtest shows a typical error of ±14.8%, with 100% 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 →
20253.61.06.3
20263.50.896.2
20273.40.786.1
20283.30.676.0
20293.20.555.8

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 →
Laclede1520241994
Mcfall1420241994
Lucerne1420212016
Huntsville1320241967
Norborne1320232006
Stet1219951972
Trenton1120241967
Bolckow1119921967
Emden1120242017
Hamilton1019851972
Madison920241971
Sticklervill920241970
Frazier820241967
Kearney820241994
Gildehouse819891978
Doe Run820242016
Marshfield720231994
Millwood720241999
Frankford720241985
Ohio620241972
Sni Mills619901967
Warren619841967
Kahoka619981967
Tarkio619891968
Barks620241994

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 2026-05-22.