BirdAnalyst
Species · BCR 9 · BBS 2025 Release · 1966–2024

Double-crested Cormorant In Great Basin

All regionsGreat BasinWetland birds

Double-crested Cormorant in Great Basin has held roughly steady: up 7% on the route-weighted index since 1971.

+7%Since 1971TrendPercent 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 →
75Routes 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 →
55YearsYears 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 Double-crested Cormorant in Great Basin. See the full index history below.

Forecast

If the recent trend holds, Double-crested Cormorant in Great Basin is projected to rise about 155% by 2029 — from 0.79 in 2024 to a central estimate of 2.0 (95% range 0.00–4.7). A 5-year backtest shows a typical error of ±970.7%, with 60% of held-out values landing inside the 95% band.

+155%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 →
2.0Projected 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 →
0.00–4.795% 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 →
±970.7%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 Great Basin is projected to rise about 155% by 2029 — from 0.79 in 2024 to a central estimate of 2.0 (95% range 0.00–4.7). A 5-year backtest shows a typical error of ±970.7%, with 60% of held-out values landing inside the 95% band.19692029
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 →
20252.00.004.7
20262.00.004.7
20272.00.004.7
20282.00.004.7
20292.00.004.7

Routes In Great Basin

Routes recording Double-crested Cormorant in Great Basin.
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 →
DorrisCALIFORNIA722019
CedarvilleCALIFORNIA602024
GoshenUTAH402024
Hanford SiteWASHINGTON391996
Iron GateCALIFORNIA272019
CallaoUTAH192016
Moses LakeWASHINGTON122017
Bear RiverUTAH92023
PrincetonOREGON81985
Ruby ValleyNEVADA72001
Malheur NwrOREGON71998
SpringfieldIDAHO62015
Blackft ResIDAHO62008
PotholesWASHINGTON62015
MesaWASHINGTON62004
IngallsCALIFORNIA51998
Dell SpringOREGON51989
Horn RapidsWASHINGTON52024
LikelyCALIFORNIA42015
PocatelloIDAHO42006
Turnbull NwrWASHINGTON42019
NubieberCALIFORNIA31993
Daniels ResIDAHO32000
Dobbin CreekNEVADA31987
Modoc PointOREGON32018

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