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Species · BCR 19 · BBS 2026 Release · 1966–2025

Brown Thrasher In Central Mixed Grass Prairie

All regionsCentral Mixed Grass PrairieForest birds

Brown Thrasher in Central Mixed Grass Prairie has declined: down 39% on the route-weighted index since 1969.

-39%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 →
113Routes In RegionSurvey 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 SignalsNotable 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 Central Mixed Grass Prairie. See the full index history below.

Brown Thrasher In Central Mixed Grass Prairie Population Forecast

If the recent trend holds, Brown Thrasher in Central Mixed Grass Prairie is projected to stay roughly flat through 2030, near 4.7 (95% range 3.1–6.3). A 5-year backtest shows a typical error of ±13.7%, with 100% of held-out values landing inside the 95% band.

-7%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 →
4.7Projected 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 →
3.1–6.395% 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 →
±13.7%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 Central Mixed Grass Prairie is projected to stay roughly flat through 2030, near 4.7 (95% range 3.1–6.3). A 5-year backtest shows a typical error of ±13.7%, with 100% of held-out values landing inside the 95% band.19672030
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 →
20264.93.36.6
20274.93.36.5
20284.83.26.4
20294.83.26.4
20304.73.16.3

Routes In Central Mixed Grass Prairie

Routes recording Brown Thrasher in Central Mixed Grass Prairie.
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 →
SurpriseNEBRASKA422025
PhillipsburgKANSAS282025
HanoverKANSAS222025
JewellKANSAS202005
HollenbergKANSAS192025
BeloitKANSAS192003
LibertyNEBRASKA192003
BelvidereNEBRASKA182025
CovertKANSAS172025
Liberty 2NEBRASKA162007
SumnerNEBRASKA152025
ChapmanKANSAS141981
KanopolisKANSAS132025
Beloit 2KANSAS132018
HamptonNEBRASKA132025
BradyNEBRASKA122025
LoganKANSAS112025
BartleyNEBRASKA112025
Berwyn 2NEBRASKA112025
BartlettNEBRASKA101976
Ft Sill EastOKLAHOMA101994
Liberty 3NEBRASKA92025
HendleyNEBRASKA92025
St JohnKANSAS82019
MinneapolisKANSAS82019

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.