BirdAnalyst
Species · BCR 37 · BBS 2026 Release · 1966–2025

Brown-headed Cowbird In Gulf Coastal Prairie

All regionsGulf Coastal PrairieGeneralists

Brown-headed Cowbird in Gulf Coastal Prairie has edged down: down 11% on the route-weighted index since 1969.

-11%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 →
48Routes 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 Gulf Coastal Prairie. See the full index history below.

Brown-headed Cowbird In Gulf Coastal Prairie Population Forecast

If the recent trend holds, Brown-headed Cowbird in Gulf Coastal Prairie is projected to rise about 65% by 2030 — from 7.3 in 2025 to a central estimate of 12 (95% range 5.2–19). A 5-year backtest shows a typical error of ±28.1%, with 100% of held-out values landing inside the 95% band.

+65%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 →
12Projected 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 →
5.2–1995% 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 →
±28.1%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-headed Cowbird in Gulf Coastal Prairie is projected to rise about 65% by 2030 — from 7.3 in 2025 to a central estimate of 12 (95% range 5.2–19). A 5-year backtest shows a typical error of ±28.1%, 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 →
2026125.019
2027125.119
2028125.119
2029125.219
2030125.219

Routes In Gulf Coastal Prairie

Routes recording Brown-headed Cowbird in Gulf Coastal 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 →
WoodlawnLOUISIANA1592021
Forked Island 2LOUISIANA642011
Ltl Chenier 2LOUISIANA322011
Sabine NwrLOUISIANA282002
Goliad PrairieTEXAS282016
McfaddinTEXAS252016
Forked IslandLOUISIANA232025
Loyola BeachTEXAS232009
CreoleLOUISIANA221987
IndianolaTEXAS192024
VanderbiltTEXAS171976
Oyster LakeTEXAS172025
Ville PlatteLOUISIANA132019
EstherLOUISIANA122025
Grand IsleLOUISIANA122019
Ltl ChenierLOUISIANA122025
Rock IslandTEXAS112025
Loyola Beach 2TEXAS112025
JuniorLOUISIANA101991
LafitteLOUISIANA91991
Vinton 2LOUISIANA92025
San PedroTEXAS92025
WinnieTEXAS82025
Bayside 3TEXAS72025
Gran ChenierLOUISIANA61980

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