BirdAnalyst
Species · Indiana · BBS 2026 Release · 1966–2025

Brown Thrasher Population Trend in Indiana

All statesForest birds

Brown Thrasher in Indiana has fallen sharply: down 50% on the route-weighted index since 1968.

-50%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 →
59YearsYears 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 →

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 Indiana: down 50% on the route-weighted index since 1968.

Brown Thrasher Population Forecast in Indiana

If the recent trend holds, Brown Thrasher in Indiana is projected to stay roughly flat through 2030, near 2.4 (95% range 1.1–3.7). A 5-year backtest shows a typical error of ±12.5%, with 100% of held-out values landing inside the 95% band.

-4%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 →
2.4Projected 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 →
1.1–3.795% 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 →
±12.5%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 Indiana is projected to stay roughly flat through 2030, near 2.4 (95% range 1.1–3.7). A 5-year backtest shows a typical error of ±12.5%, with 100% of held-out values landing inside the 95% band.19662030
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 →
20262.61.33.9
20272.51.23.8
20282.51.23.8
20292.41.13.7
20302.41.13.7

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
Washington820251987
Indian Spgs820251982
Knox620251981
Brazil620251966
Spencer620241967
Brookville620251966
Celestine620251979
Georgia620251999
Jamestown520251986
Cumback520251966
Cross Plains520251999
Kankakee Sands520252000
Packertown420041967
Millersburg420191981
Crown Point420251999
Cyprss420251999
Ellis320231966
Thorntown320251982
Muncie319971981
Friendswood320241986
Azalia320251982
Corydon320251966
Vevay320251966
Scottsburg320251982

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 2026-08-14.