BirdAnalyst
Species · BCR 16 · BBS 2026 Release · 1966–2025

Double-crested Cormorant In Southern Rockies / Colorado Plateau

All regionsSouthern Rockies / Colorado PlateauWetland birds

Double-crested Cormorant in Southern Rockies / Colorado Plateau has surged: up 14× on the route-weighted index since 1978.

14×Since 1978TrendPercent 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 →
25Routes 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 →
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 SignalsNotable 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 Southern Rockies / Colorado Plateau: up 14× on the route-weighted index since 1978.

Double-crested Cormorant In Southern Rockies / Colorado Plateau Population Forecast

If the recent trend holds, Double-crested Cormorant in Southern Rockies / Colorado Plateau is projected to fall about 46% by 2030 — from 1.9 in 2025 to a central estimate of 1.0 (95% range 0.22–1.8). A 5-year backtest shows a typical error of ±65.1%, with 20% of held-out values landing inside the 95% band.

-46%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 →
1.0Projected 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 →
0.22–1.895% 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 →
±65.1%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 Southern Rockies / Colorado Plateau is projected to fall about 46% by 2030 — from 1.9 in 2025 to a central estimate of 1.0 (95% range 0.22–1.8). A 5-year backtest shows a typical error of ±65.1%, with 20% of held-out values landing inside the 95% band.19762030
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 →
20260.920.131.7
20270.940.151.7
20280.960.181.7
20290.980.201.8
20301.00.221.8

Routes In Southern Rockies / Colorado Plateau

Routes recording Double-crested Cormorant in Southern Rockies / Colorado Plateau.
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 →
GuffeyCOLORADO2722025
AnethUTAH102008
Stillwater PassCOLORADO72009
Sybille CynWYOMING62013
Animas 2COLORADO32021
DulceNEW-MEXICO32025
DoylevilleCOLORADO22003
BrookhurstWYOMING22022
HarmonyCOLORADO12008
DoloresCOLORADO11984
WaldenCOLORADO12025
TarryallCOLORADO12025
CortezCOLORADO12007
San LuisCOLORADO12021
Deadman Rd.COLORADO12010
De BequeCOLORADO12012
AntonitoCOLORADO11999
Gold HillCOLORADO12006
Cortez 2COLORADO12009
FarmingtonNEW-MEXICO11977
JensenUTAH12011
Dixie NfUTAH12008
MoabUTAH12017
KamasUTAH12022
BufordWYOMING11998

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