BirdAnalyst
Species · BCR 21 · BBS 2026 Release · 1966–2025

Brown-headed Cowbird In Oaks and Prairies

All regionsOaks and PrairiesGeneralists

Brown-headed Cowbird in Oaks and Prairies 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 →
74Routes 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-headed Cowbird has fallen sharply in Oaks and Prairies: down 56% on the route-weighted index since 1969.

Brown-headed Cowbird In Oaks and Prairies Population Forecast

If the recent trend holds, Brown-headed Cowbird in Oaks and Prairies is projected to fall about 34% by 2030 — from 16 in 2025 to a central estimate of 10 (95% range 3.8–17). A 5-year backtest shows a typical error of ±15%, with 100% of held-out values landing inside the 95% band.

-34%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 →
10Projected 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 →
3.8–1795% 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 →
±15%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 Oaks and Prairies is projected to fall about 34% by 2030 — from 16 in 2025 to a central estimate of 10 (95% range 3.8–17). A 5-year backtest shows a typical error of ±15%, 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 →
2026124.918
2027114.618
2028114.418
2029114.117
2030103.817

Routes In Oaks and Prairies

Routes recording Brown-headed Cowbird in Oaks 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 →
Mill CreekOKLAHOMA572025
ArdmoreOKLAHOMA432025
E GeorgetownTEXAS401979
DuranTEXAS381999
OakwoodTEXAS371995
SkiatookOKLAHOMA332019
LocoOKLAHOMA311985
GrafordTEXAS312025
WalburgTEXAS312025
HeyburnOKLAHOMA302025
HobsonTEXAS302025
LydiaTEXAS282025
FanninTEXAS282025
DecaturTEXAS242024
DuncanOKLAHOMA222025
Massey LakeTEXAS222025
Arenosa CrkTEXAS212025
BriteTEXAS212025
MuldoonTEXAS202025
CottonwoodTEXAS202025
Three RiversTEXAS202025
SchroederTEXAS181997
CampbelltonTEXAS182024
OsageTEXAS162025
SeldenTEXAS162025

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