BirdAnalyst
Species · BCR 11 · BBS 2026 Release · 1966–2025

Brown Thrasher In Prairie Potholes

All regionsPrairie PotholesForest birds

Brown Thrasher in Prairie Potholes has fallen sharply: down 56% on the route-weighted index since 1969.

-56%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 →
120Routes 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 →

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 Prairie Potholes: down 56% on the route-weighted index since 1969.

Brown Thrasher In Prairie Potholes Population Forecast

If the recent trend holds, Brown Thrasher in Prairie Potholes is projected to fall about 10% by 2030 — from 2.2 in 2025 to a central estimate of 1.9 (95% range 0.02–3.9). A 5-year backtest shows a typical error of ±12.1%, with 100% of held-out values landing inside the 95% band.

-10%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 →
1.9Projected 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 →
0.02–3.995% 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 →
±12.1%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 Prairie Potholes is projected to fall about 10% by 2030 — from 2.2 in 2025 to a central estimate of 1.9 (95% range 0.02–3.9). A 5-year backtest shows a typical error of ±12.1%, 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 →
20262.20.264.1
20272.10.204.0
20282.10.144.0
20292.00.083.9
20301.90.023.9

Routes In Prairie Potholes

Routes recording Brown Thrasher in Prairie Potholes.
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 →
Eagle CreekNEBRASKA132025
TracyMINNESOTA122025
ScrantonIOWA112025
Wolf PointMONTANA112024
TildenNEBRASKA102025
ZearingIOWA81995
MaynardMINNESOTA82015
LambertMONTANA82025
Winside 2NEBRASKA82022
SydneyNORTH-DAKOTA81983
FairmontMINNESOTA72025
WorthingtonMINNESOTA72024
WinsideNEBRASKA72003
PoncaNEBRASKA72025
EdgeleyNORTH-DAKOTA72024
VolgaSOUTH-DAKOTA72025
BrittonSOUTH-DAKOTA62023
CondeSOUTH-DAKOTA61984
GettysburgSOUTH-DAKOTA62023
WalcottNORTH-DAKOTA52023
White LakeSOUTH-DAKOTA52011
GormanSOUTH-DAKOTA52009
BurchinalIOWA42024
TenneyMINNESOTA42016
SacoMONTANA42025

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