BirdAnalyst
Species · BCR 11 · BBS 2025 Release · 1966–2024

Double-crested Cormorant In Prairie Potholes

All regionsPrairie PotholesWetland birds

Double-crested Cormorant in Prairie Potholes has surged: up 235% on the route-weighted index since 1969.

+235%Since 1969TrendPercent 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 →
86Routes 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 →
57YearsYears 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 Prairie Potholes: up 235% on the route-weighted index since 1969.

Forecast

If the recent trend holds, Double-crested Cormorant in Prairie Potholes is projected to rise about 42% by 2029 — from 3.9 in 2024 to a central estimate of 5.5 (95% range 1.9–9.2). A 5-year backtest shows a typical error of ±164.4%, with 60% of held-out values landing inside the 95% band.

+42%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 →
5.5Projected 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 →
1.9–9.295% 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 →
±164.4%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 Prairie Potholes is projected to rise about 42% by 2029 — from 3.9 in 2024 to a central estimate of 5.5 (95% range 1.9–9.2). A 5-year backtest shows a typical error of ±164.4%, with 60% of held-out values landing inside the 95% band.19672029
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 →
20255.21.68.8
20265.31.68.9
20275.41.79.0
20285.51.89.1
20295.51.99.2

Routes In Prairie Potholes

Routes recording Double-crested Cormorant in Prairie Potholes.
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 →
Horsehead LkNORTH-DAKOTA632024
DanzigNORTH-DAKOTA432014
StanleyNORTH-DAKOTA432024
Big StoneMINNESOTA412012
Lakota 2NORTH-DAKOTA302024
WorthingtonMINNESOTA282022
Turtle MtnsNORTH-DAKOTA262024
WebsterNORTH-DAKOTA242024
Sheyenne LkNORTH-DAKOTA222024
Danzig 2NORTH-DAKOTA222024
ChinookMONTANA182017
GlasgowMONTANA171968
AbercrombieNORTH-DAKOTA132005
RaymondSOUTH-DAKOTA132021
WylieMINNESOTA121998
RoswellSOUTH-DAKOTA112014
Great FallsMONTANA92016
WalcottNORTH-DAKOTA92017
EdgeleyNORTH-DAKOTA92023
Wild RoseNORTH-DAKOTA92024
MontpelierNORTH-DAKOTA92024
EmeradoNORTH-DAKOTA82024
TurtonSOUTH-DAKOTA82008
CarpioNORTH-DAKOTA62023
BraddockNORTH-DAKOTA62022

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