BirdAnalyst
Species · BCR 18 · BBS 2026 Release · 1966–2025

Brown-headed Cowbird In Shortgrass Prairie

All regionsShortgrass PrairieGeneralists

Brown-headed Cowbird in Shortgrass Prairie has increased: up 33% on the route-weighted index since 1969.

+33%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 →
137Routes 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 →

No notable trend signals for Brown-headed Cowbird in Shortgrass Prairie. See the full index history below.

Brown-headed Cowbird In Shortgrass Prairie Population Forecast

If the recent trend holds, Brown-headed Cowbird in Shortgrass Prairie is projected to stay roughly flat through 2030, near 5.2 (95% range 3.6–6.8). A 5-year backtest shows a typical error of ±13.7%, with 100% of held-out values landing inside the 95% band.

-8%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 →
5.2Projected 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 →
3.6–6.895% 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 →
±13.7%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 Shortgrass Prairie is projected to stay roughly flat through 2030, near 5.2 (95% range 3.6–6.8). A 5-year backtest shows a typical error of ±13.7%, 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 →
20265.03.46.6
20275.13.56.6
20285.13.56.7
20295.23.66.7
20305.23.66.8

Routes In Shortgrass Prairie

Routes recording Brown-headed Cowbird in Shortgrass 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 →
Fort MorganCOLORADO622025
CactusTEXAS512024
PlymellKANSAS352025
BereaNEBRASKA352025
JulesburgCOLORADO242021
PaxtonNEBRASKA222016
AmherstCOLORADO182024
Hay SpringsNEBRASKA182025
FloydNEW-MEXICO182019
BoyeroCOLORADO162017
DaltonNEBRASKA162025
ChampionNEBRASKA162018
GilpinCOLORADO152025
Clear LakeOKLAHOMA142025
YoderWYOMING142025
FlemingCOLORADO132025
Wildhorse LCOLORADO132025
Arsenal 2COLORADO132025
RuletonKANSAS132022
BrownsonNEBRASKA132025
WakaTEXAS132023
KirkCOLORADO122023
Agate 2NEBRASKA112025
Pine BluffWYOMING112025
NeegrandeCOLORADO102025

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