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

Double-crested Cormorant Population Trend in Texas

All statesWetland birds

Double-crested Cormorant in Texas has surged: up 695% on the route-weighted index since 1975.

+695%Since 1975TrendPercent 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 →
57Routes 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 →
45YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Double-crested Cormorant 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 increasecomputed 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 →

Double-crested Cormorant has surged in Texas: up 695% on the route-weighted index since 1975.

Double-crested Cormorant Population Forecast in Texas

If the recent trend holds, Double-crested Cormorant in Texas is projected to stay roughly flat through 2029, near 0.13 (95% range 0.00–0.31). A 5-year backtest shows a typical error of ±127.1%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.13Projected 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 →
0.00–0.3195% 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 →
±127.1%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, Double-crested Cormorant in Texas is projected to stay roughly flat through 2029, near 0.13 (95% range 0.00–0.31). A 5-year backtest shows a typical error of ±127.1%, with 100% of held-out values landing inside the 95% band.19732029
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 →
20250.130.000.30
20260.130.000.31
20270.130.000.31
20280.130.000.31
20290.130.000.31

Double-crested Cormorant Survey Routes in Texas

Routes recording Double-crested Cormorant 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 →
Chandler 24020182008
Waka2520102010
Katy2019851985
Bayside1020101994
Petronila720162016
Lag Atascosa619921989
Chinquapin520212021
Yoakum420042004
Encinal 2420232023
Smyrna420052005
Cayuga320242004
Crossroads319991999
Athens320111973
Presidio320212021
Padre Island Pais220152015
Indianola220071988
Campbellton220042000
Stowell219941984
Massey Lake220231974
Kosse220162016
Quitman Canyon 2220212017
Creedmore220002000
Fannin220012001
Kingsville119871982
Schroeder119821982

Double-crested Cormorant 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.