BirdAnalyst
Species · BCR 19 · BBS 2025 Release · 1966–2024

Double-crested Cormorant In Central Mixed Grass Prairie

All regionsCentral Mixed Grass PrairieWetland birds

Double-crested Cormorant in Central Mixed Grass Prairie has surged: up 981% on the route-weighted index since 1974.

+981%Since 1974TrendPercent 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 →
32Routes 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 →
49YearsYears 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 Central Mixed Grass Prairie: up 981% on the route-weighted index since 1974.

Forecast

If the recent trend holds, Double-crested Cormorant in Central Mixed Grass Prairie is projected to stay roughly flat through 2029, near 0.33 (95% range 0.00–1.2). A 5-year backtest shows a typical error of ±53.7%, with 100% of held-out values landing inside the 95% band.

-0%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 →
0.33Projected 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 →
0.00–1.295% 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 →
±53.7%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 Central Mixed Grass Prairie is projected to stay roughly flat through 2029, near 0.33 (95% range 0.00–1.2). A 5-year backtest shows a typical error of ±53.7%, with 100% 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 →
20250.330.001.2
20260.330.001.2
20270.330.001.2
20280.330.001.2
20290.330.001.2

Routes In Central Mixed Grass Prairie

Routes recording Double-crested Cormorant in Central Mixed Grass Prairie.
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 →
AlbertKANSAS222023
JetOKLAHOMA202024
ChapmanKANSAS171981
KennedyNEBRASKA172017
Piester LakeNEBRASKA142023
Crescent LkNEBRASKA112014
SumnerNEBRASKA61997
AlmeriaNEBRASKA51992
KenesawNEBRASKA42002
PhillipsburgKANSAS32017
ArthurNEBRASKA32023
ErickOKLAHOMA32019
CoatsKANSAS22002
BrownleeNEBRASKA22024
MullenNEBRASKA22003
NenzelNEBRASKA22021
Wichita Mts WestOKLAHOMA22015
DaltonKANSAS11995
HaysKANSAS12008
JewellKANSAS11986
LoganKANSAS12012
SolomonKANSAS12015
BelvidereNEBRASKA12022
SewardNEBRASKA12001
SurpriseNEBRASKA12022

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