BirdAnalyst
Species · BCR 18 · BBS 2025 Release · 1966–2024

Double-crested Cormorant In Shortgrass Prairie

All regionsShortgrass PrairieWetland birds

Double-crested Cormorant in Shortgrass Prairie has surged: up 308% on the route-weighted index since 1987.

+308%Since 1987TrendPercent 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 →
22Routes 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 →
39YearsYears 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 Shortgrass Prairie: up 308% on the route-weighted index since 1987.

Forecast

If the recent trend holds, Double-crested Cormorant in Shortgrass Prairie is projected to rise about 190% by 2029 — from 0.20 in 2024 to a central estimate of 0.59 (95% range 0.03–1.2). A 5-year backtest shows a typical error of ±125.2%, with 100% of held-out values landing inside the 95% band.

+190%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 →
0.59Projected 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 →
0.03–1.295% 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 →
±125.2%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 Shortgrass Prairie is projected to rise about 190% by 2029 — from 0.20 in 2024 to a central estimate of 0.59 (95% range 0.03–1.2). A 5-year backtest shows a typical error of ±125.2%, with 100% of held-out values landing inside the 95% band.19852029
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 →
20250.570.001.1
20260.570.011.1
20270.580.011.2
20280.590.021.2
20290.590.031.2

Routes In Shortgrass Prairie

Routes recording Double-crested Cormorant in Shortgrass 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 →
WakaTEXAS252010
HudsonCOLORADO72024
Wildhorse LCOLORADO72024
JulesburgCOLORADO72019
ArsenalCOLORADO72015
HaswellCOLORADO62006
Last ChanceCOLORADO51994
NeegrandeCOLORADO42018
Fort MorganCOLORADO32021
Arsenal 2COLORADO32024
FeltOKLAHOMA32016
StonehamCOLORADO22014
PaxtonNEBRASKA22016
KiowaCOLORADO12005
AbarrCOLORADO12005
NunnCOLORADO12018
LakinKANSAS11993
Murray LakeNEBRASKA12011
Agate 2NEBRASKA12018
PostTEXAS12017
LamesaTEXAS12022
YoderWYOMING12012

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