BirdAnalyst
Species · BCR 17 · BBS 2026 Release · 1966–2025

Brown-headed Cowbird In Badlands and Prairies

All regionsBadlands and PrairiesGeneralists

Brown-headed Cowbird in Badlands and Prairies has surged: up 103% on the route-weighted index since 1969.

+103%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 →
138Routes 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 increasecomputed 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-headed Cowbird has surged in Badlands and Prairies: up 103% on the route-weighted index since 1969.

Brown-headed Cowbird In Badlands and Prairies Population Forecast

If the recent trend holds, Brown-headed Cowbird in Badlands and Prairies is projected to stay roughly flat through 2030, near 40 (95% range 28–51). A 5-year backtest shows a typical error of ±28.8%, with 100% of held-out values landing inside the 95% band.

+6%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 →
40Projected 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 →
28–5195% 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 →
±28.8%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-headed Cowbird in Badlands and Prairies is projected to stay roughly flat through 2030, near 40 (95% range 28–51). A 5-year backtest shows a typical error of ±28.8%, 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 →
2026392750
2027392750
2028392851
2029402851
2030402851

Routes In Badlands and Prairies

Routes recording Brown-headed Cowbird in Badlands and Prairies.
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 →
VolunteerSOUTH-DAKOTA2812025
Glen UllinNORTH-DAKOTA2272025
Ft ThompsonSOUTH-DAKOTA1942011
BentleyNORTH-DAKOTA1672024
Ft YatesNORTH-DAKOTA1622004
PromiseSOUTH-DAKOTA1542015
RockyfordSOUTH-DAKOTA1232025
AlbionMONTANA1212025
RosebudSOUTH-DAKOTA1182011
GorhamNORTH-DAKOTA1162025
DickinsonNORTH-DAKOTA1082025
LodgepoleSOUTH-DAKOTA972025
Cedar PassSOUTH-DAKOTA932025
Jordan SouthMONTANA902025
Cedar CreekNORTH-DAKOTA902022
SolenNORTH-DAKOTA902025
Fort PierreSOUTH-DAKOTA902025
MaurineSOUTH-DAKOTA852025
IsabelSOUTH-DAKOTA832015
RevaSOUTH-DAKOTA822025
OttumwaSOUTH-DAKOTA792025
ZapNORTH-DAKOTA772024
OwankaSOUTH-DAKOTA752022
Dunn CenterNORTH-DAKOTA732025
BowmanNORTH-DAKOTA732025

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