BirdAnalyst
Species · BCR 17 · BBS 2025 Release · 1966–2024

Double-crested Cormorant In Badlands and Prairies

All regionsBadlands and PrairiesWetland birds

Double-crested Cormorant in Badlands and Prairies has surged: up 12× on the route-weighted index since 1969.

12×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 →
54Routes 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 →
53YearsYears 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 Badlands and Prairies: up 12× on the route-weighted index since 1969.

Double-crested Cormorant In Badlands and Prairies Population Forecast

If the recent trend holds, Double-crested Cormorant in Badlands and Prairies is projected to fall about 21% by 2029 — from 0.89 in 2024 to a central estimate of 0.70 (95% range 0.00–1.8). A 5-year backtest shows a typical error of ±52.9%, with 60% of held-out values landing inside the 95% band.

-21%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 →
0.70Projected 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 →
0.00–1.895% 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 →
±52.9%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 Badlands and Prairies is projected to fall about 21% by 2029 — from 0.89 in 2024 to a central estimate of 0.70 (95% range 0.00–1.8). A 5-year backtest shows a typical error of ±52.9%, 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 →
20250.670.001.8
20260.680.001.8
20270.690.001.8
20280.690.001.8
20290.700.001.8

Routes In Badlands and Prairies

Routes recording Double-crested Cormorant in Badlands and Prairies.
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 →
Two DotMONTANA502024
Soda WellWYOMING171981
Oglala Nat. Grass.NEBRASKA122019
HayesSOUTH-DAKOTA92001
LacreekSOUTH-DAKOTA92022
CrookstonNEBRASKA72019
GolvaNORTH-DAKOTA62019
ArdmoreSOUTH-DAKOTA62015
RoundupMONTANA52019
Glen UllinNORTH-DAKOTA52000
ChamberlainSOUTH-DAKOTA52011
Ft ThompsonSOUTH-DAKOTA52011
ForsythMONTANA32004
St XavierMONTANA31993
Wheat BasinMONTANA32024
Ft YatesNORTH-DAKOTA31986
DickinsonNORTH-DAKOTA32004
LaplantSOUTH-DAKOTA31999
KayceeWYOMING32024
SavageMONTANA21987
AlbionMONTANA21993
TobaccoNORTH-DAKOTA21993
BowmanNORTH-DAKOTA22018
GorhamNORTH-DAKOTA22016
LodgepoleSOUTH-DAKOTA22019

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