BirdAnalyst
Species · Texas · BBS 2026 Release · 1966–2025

Brown-headed Cowbird Population Trend in Texas

All statesGeneralists

Brown-headed Cowbird in Texas has fallen sharply: down 60% on the route-weighted index since 1969.

-60%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 →
249Routes In StateSurvey 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 Brown-headed Cowbird Trends in TexasNotable 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 Texas: down 60% on the route-weighted index since 1969.

Brown-headed Cowbird Population Forecast in Texas

If the recent trend holds, Brown-headed Cowbird in Texas is projected to fall about 29% by 2030 — from 8.9 in 2025 to a central estimate of 6.3 (95% range 2.8–9.8). A 5-year backtest shows a typical error of ±10.1%, with 100% of held-out values landing inside the 95% band.

-29%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 →
6.3Projected 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 →
2.8–9.895% 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 →
±10.1%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 Texas is projected to fall about 29% by 2030 — from 8.9 in 2025 to a central estimate of 6.3 (95% range 2.8–9.8). A 5-year backtest shows a typical error of ±10.1%, 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 →
20267.23.711
20277.03.511
20286.83.210
20296.53.010
20306.32.89.8

Brown-headed Cowbird Survey Routes in Texas

Routes recording Brown-headed Cowbird in Texas.
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 →
Cactus5120241994
Hondo4820251969
E Georgetown4019791967
Duran3819991995
Oakwood3719951967
Georgetown3119851967
Graford3120251967
Walburg3120251980
Hobson3020251968
Quitman Cyn.2920091999
Lydia2820251967
Fannin2820251998
Goliad Prairie2820162004
Mcfaddin2520162006
Decatur2420241995
Chandler2320041968
Pidcoke 22320252018
Loyola Beach2320091994
Catarina2220101970
Boerne2220251967
Massey Lake2220251970
Shields 22220252004
Arenosa Crk2120251968
Utopia2120251969
Brite2120251994

Brown-headed Cowbird Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseeutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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