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

Double-crested Cormorant Population Trend in Oklahoma

All statesWetland birds

Double-crested Cormorant in Oklahoma has surged: up 720% on the route-weighted index since 1990.

+720%Since 1990TrendPercent 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 →
12Routes 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 →
22YearsYears 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 OklahomaNotable 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 Oklahoma: up 720% on the route-weighted index since 1990.

Double-crested Cormorant Population Forecast in Oklahoma

If the recent trend holds, Double-crested Cormorant in Oklahoma is projected to fall about 64% by 2029 — from 0.69 in 2024 to a central estimate of 0.25 (95% range 0.00–0.52). A 5-year backtest shows a typical error of ±133.7%, with 80% of held-out values landing inside the 95% band.

-64%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 →
0.25Projected 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 →
0.00–0.5295% 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 →
±133.7%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, Double-crested Cormorant in Oklahoma is projected to fall about 64% by 2029 — from 0.69 in 2024 to a central estimate of 0.25 (95% range 0.00–0.52). A 5-year backtest shows a typical error of ±133.7%, with 80% of held-out values landing inside the 95% band.19822029
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 →
20250.230.000.50
20260.230.000.50
20270.240.000.51
20280.240.000.51
20290.250.000.52

Double-crested Cormorant Survey Routes in Oklahoma

Routes recording Double-crested Cormorant in Oklahoma.
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 →
Jet2020241995
Wainwright919971992
Felt320162016
Erick320192018
Wichita Mts West220152015
Big Cedar119831983
Blanco119931990
Hunter120162016
Pushmataha120172017
Cooperton120172017
Collinsville119821982
Arapaho120022002

Double-crested Cormorant Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.