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Species · BCR 19 · BBS 2025 Release · 1966–2024

Brown Thrasher In Central Mixed Grass Prairie

All regionsCentral Mixed Grass PrairieGeneralists

Brown Thrasher in Central Mixed Grass Prairie has declined: down 42% on the route-weighted index since 1969.

-42%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 →
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 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.

Forecast

If the recent trend holds, Brown Thrasher in Central Mixed Grass Prairie is projected to stay roughly flat through 2029, near 4.8 (95% range 3.1–6.4). A 5-year backtest shows a typical error of ±13.8%, with 100% of held-out values landing inside the 95% band.

-9%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 →
4.8Projected 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 →
3.1–6.495% 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 →
±13.8%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 2029, near 4.8 (95% range 3.1–6.4). A 5-year backtest shows a typical error of ±13.8%, 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 →
20255.03.46.6
20264.93.36.6
20274.93.36.5
20284.83.26.5
20294.83.16.4

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 →
CovertKANSAS382024
HamptonNEBRASKA312024
SurpriseNEBRASKA252024
BelvidereNEBRASKA232024
KanopolisKANSAS202024
JewellKANSAS202005
BeloitKANSAS192003
LibertyNEBRASKA192003
PhillipsburgKANSAS172022
HanoverKANSAS162023
LoganKANSAS162022
Liberty 2NEBRASKA162007
BartleyNEBRASKA152024
BradyNEBRASKA152024
ChapmanKANSAS141981
BerwetKANSAS142024
SumnerNEBRASKA142024
Liberty 3NEBRASKA142024
Beloit 2KANSAS132018
KenesawNEBRASKA132024
Jewell 2KANSAS122024
SolomonKANSAS112019
HollenbergKANSAS102023
BartlettNEBRASKA101976
Ft Sill EastOKLAHOMA101994

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