BirdAnalyst
Species · North Dakota · BBS 2025 Release · 1966–2024

Brown Thrasher Population Trend in North Dakota

All statesGeneralists

Brown Thrasher in North Dakota has declined: down 44% on the route-weighted index since 1969.

-44%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 →
51Routes 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 North DakotaNotable 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 North Dakota. See the full index history below.

Brown Thrasher Population Forecast in North Dakota

If the recent trend holds, Brown Thrasher in North Dakota is projected to rise about 10% by 2029 — from 2.0 in 2024 to a central estimate of 2.2 (95% range 0.00–4.6). A 5-year backtest shows a typical error of ±26%, with 100% of held-out values landing inside the 95% band.

+10%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 →
2.2Projected 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 →
0.00–4.695% 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 →
±26%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 North Dakota is projected to rise about 10% by 2029 — from 2.0 in 2024 to a central estimate of 2.2 (95% range 0.00–4.6). A 5-year backtest shows a typical error of ±26%, 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 →
20252.40.004.8
20262.30.004.8
20272.30.004.7
20282.30.004.7
20292.20.004.6

Brown Thrasher Survey Routes in North Dakota

Routes recording Brown Thrasher in North Dakota.
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 →
Solen920242005
Sydney819831967
Edgeley720241980
Regan720221968
Tobacco620191968
Walcott520231967
Zap520241967
Golva520231979
Kempton420171967
Buchanan420241967
Bowman420241967
Roosevelt Pk420191982
Cedar Creek420221969
Niles320241989
Dickinson320241969
Dunn Center320241969
Forman220241968
Lake George220221967
Danzig220141982
Webster220211989
Rolla220221969
Ft Yates220041968
Denbigh220241968
Carson220241988
Emerado120231973

Brown Thrasher Population Trend in Other States

alabamaarkansascoloradoconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsinwyoming

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