BirdAnalyst
Species · BCR 23 · BBS 2026 Release · 1966–2025

Brown-headed Cowbird In Prairie Hardwood Transition

All regionsPrairie Hardwood TransitionGeneralists

Brown-headed Cowbird in Prairie Hardwood Transition has declined: down 26% on the route-weighted index since 1968.

-26%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 →
161Routes 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 →
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 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-headed Cowbird in Prairie Hardwood Transition. See the full index history below.

Brown-headed Cowbird In Prairie Hardwood Transition Population Forecast

If the recent trend holds, Brown-headed Cowbird in Prairie Hardwood Transition is projected to stay roughly flat through 2030, near 15 (95% range 11–19). A 5-year backtest shows a typical error of ±3%, with 100% of held-out values landing inside the 95% band.

-1%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 →
15Projected 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 →
11–1995% 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 →
±3%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 Prairie Hardwood Transition is projected to stay roughly flat through 2030, near 15 (95% range 11–19). A 5-year backtest shows a typical error of ±3%, 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 →
2026151119
2027151119
2028151119
2029151119
2030151119

Routes In Prairie Hardwood Transition

Routes recording Brown-headed Cowbird in Prairie Hardwood Transition.
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 →
GrimmsWISCONSIN962021
PackertownINDIANA502004
Sherburne NrMINNESOTA502025
MillvilleMINNESOTA482025
New LondonMINNESOTA442024
Pt WashingtnWISCONSIN432024
WhitewaterMINNESOTA412000
ParisWISCONSIN362025
GuilfordILLINOIS352023
RichmondMICHIGAN342024
MinnetonkaMINNESOTA342025
Chatfield 2MINNESOTA332025
OsseoMINNESOTA322025
CadottWISCONSIN322025
PardeevilleWISCONSIN322025
KewannaINDIANA302022
EllisINDIANA302024
HartlandMICHIGAN302011
WeyerhauserWISCONSIN302025
AnnatonWISCONSIN302025
St CharlesMICHIGAN292019
Bell OakMICHIGAN292008
Caledonia 2MINNESOTA292025
LoraineWISCONSIN292025
Hazel GreenWISCONSIN292025

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