BirdAnalyst
Species · Texas · BBS 2025 Release · 1966–2024

Brown-headed Cowbird Population Trend in Texas

All statesGeneralists

Brown-headed Cowbird in Texas has fallen sharply: down 61% on the route-weighted index since 1969.

-61%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 →
246Routes 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 →
57YearsYears 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 61% 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 32% by 2029 — from 9.4 in 2024 to a central estimate of 6.4 (95% range 2.9–9.9). A 5-year backtest shows a typical error of ±11.7%, with 100% of held-out values landing inside the 95% band.

-32%Change by 2029TrendPercent 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 →
6.4Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
2.9–9.995% 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 →
±11.7%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 Texas is projected to fall about 32% by 2029 — from 9.4 in 2024 to a central estimate of 6.4 (95% range 2.9–9.9). A 5-year backtest shows a typical error of ±11.7%, with 100% of held-out values landing inside the 95% band.19672029
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 →
20257.43.811
20267.13.611
20276.93.410
20286.63.110
20296.42.99.9

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 →
Oyster Lake5820241995
Cactus5120241994
Rhome4820241967
Three Rivers4820241994
Hondo4720241969
Chinquapin4620241995
E Georgetown4019791967
Duran3819991995
Oakwood3719951967
Winnie3420241967
Georgetown3119851967
Quitman Cyn.2920091999
Dripping Spg2820241985
Goliad Prairie2820162004
Mcfaddin2520162006
Comanche2520242000
Shields 22520232004
San Saba2420241969
Decatur2420241995
Harper2320241969
Chandler2320041968
Booker2320241975
Loyola Beach2320091994
Brite2320241994
Rachal2220231967

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 2026-05-22.