BirdAnalyst
Species · BCR 16 · BBS 2025 Release · 1966–2024

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 13× on the route-weighted index since 1978.

13×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 →
44YearsYears 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 13× 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 28% by 2029 — from 1.2 in 2024 to a central estimate of 0.89 (95% range 0.15–1.6). A 5-year backtest shows a typical error of ±74%, with 0% of held-out values landing inside the 95% band.

-28%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 →
0.89Projected 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 →
0.15–1.695% 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 →
±74%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 28% by 2029 — from 1.2 in 2024 to a central estimate of 0.89 (95% range 0.15–1.6). A 5-year backtest shows a typical error of ±74%, with 0% of held-out values landing inside the 95% band.19762029
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 →
20250.810.071.5
20260.820.091.6
20270.840.111.6
20280.860.131.6
20290.890.151.6

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 →
GuffeyCOLORADO1582024
TarryallCOLORADO132023
AnethUTAH102008
Stillwater PassCOLORADO72009
Sybille CynWYOMING62013
Animas 2COLORADO32021
DoylevilleCOLORADO22003
BrookhurstWYOMING22022
HarmonyCOLORADO12008
DoloresCOLORADO11984
WaldenCOLORADO12024
CortezCOLORADO12007
San LuisCOLORADO12021
Deadman Rd.COLORADO12010
De BequeCOLORADO12012
AntonitoCOLORADO11999
Gold HillCOLORADO12006
Cortez 2COLORADO12009
FarmingtonNEW-MEXICO11977
DulceNEW-MEXICO12022
JensenUTAH12011
Dixie NfUTAH12008
MoabUTAH12017
KamasUTAH12022
BufordWYOMING11998

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