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

Brown Thrasher Population Trend in Indiana

All statesGeneralists

Brown Thrasher in Indiana has declined: down 49% on the route-weighted index since 1968.

-49%Since 1968TrendPercent 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 →
69Routes 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 IndianaNotable 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 Indiana. See the full index history below.

Brown Thrasher Population Forecast in Indiana

If the recent trend holds, Brown Thrasher in Indiana is projected to stay roughly flat through 2029, near 2.5 (95% range 1.1–3.8). A 5-year backtest shows a typical error of ±16.3%, with 100% of held-out values landing inside the 95% band.

-3%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 →
2.5Projected 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 →
1.1–3.895% 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 →
±16.3%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 Indiana is projected to stay roughly flat through 2029, near 2.5 (95% range 1.1–3.8). A 5-year backtest shows a typical error of ±16.3%, with 100% of held-out values landing inside the 95% band.19662029
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 →
20252.61.33.9
20262.61.33.9
20272.51.23.9
20282.51.23.8
20292.51.13.8

Brown Thrasher Survey Routes in Indiana

Routes recording Brown Thrasher in Indiana.
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 →
Wallace1220241999
Georgia1120241999
Pimento820241981
Jamestown820241986
Spencer620241967
Kankakee Sands620242000
Brazil520241966
Azalia520241982
Indian Spgs520241982
Celestine520241979
Frankfort520221999
Newberry520241999
Packertown420041967
Thorntown420241982
Millersburg420191981
New Phila420241982
Ellis320231966
Fowler320241966
Muncie319971981
Friendswood320241986
Washington320241987
Corydon320241966
Scottsburg320241982
Montpelier320242018
Cyprss320241999

Brown Thrasher Population Trend in Other States

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

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