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

Brown Thrasher Population Trend in Minnesota

All statesGeneralists

Brown Thrasher in Minnesota has fallen sharply: down 54% on the route-weighted index since 1969.

-54%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 →
88Routes 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 MinnesotaNotable 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 Minnesota: down 54% on the route-weighted index since 1969.

Brown Thrasher Population Forecast in Minnesota

If the recent trend holds, Brown Thrasher in Minnesota is projected to fall about 22% by 2029 — from 1.4 in 2024 to a central estimate of 1.1 (95% range 0.00–2.4). A 5-year backtest shows a typical error of ±16.5%, with 100% of held-out values landing inside the 95% band.

-22%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 →
1.1Projected 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 →
0.00–2.495% 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 →
±16.5%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 Minnesota is projected to fall about 22% by 2029 — from 1.4 in 2024 to a central estimate of 1.1 (95% range 0.00–2.4). A 5-year backtest shows a typical error of ±16.5%, 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 →
20251.30.002.6
20261.30.002.6
20271.20.002.5
20281.20.002.5
20291.10.002.4

Brown Thrasher Survey Routes in Minnesota

Routes recording Brown Thrasher in Minnesota.
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 →
Maynard820151967
Tracy820242004
Knapp720191967
Worthington720242004
Franklin720241994
Sherburne Nr720241990
Fairmont620231993
Whitewater620001994
Chandler520231969
Brook Park520241999
Chatfield 2520242003
Courtland420241978
Princeton420241969
Tenney420161978
Le Center420161993
Caledonia 2420242015
Ash Creek320231975
Millville320191967
Arlington320241967
St Stephen320161967
Gluek320191967
Evergreen320241968
Caledonia320071993
New London320241994
Glenwood320191993

Brown Thrasher Population Trend in Other States

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

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