BirdAnalyst
Species · BCR 26 · BBS 2025 Release · 1966–2024

Double-crested Cormorant In Mississippi Alluvial Valley

All regionsMississippi Alluvial ValleyWetland birds

Double-crested Cormorant in Mississippi Alluvial Valley has surged: up 981% on the route-weighted index since 1993.

+981%Since 1993TrendPercent 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 →
27Routes 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 →
31YearsYears 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 Mississippi Alluvial Valley: up 980% on the route-weighted index since 1993.

Double-crested Cormorant In Mississippi Alluvial Valley Population Forecast

If the recent trend holds, Double-crested Cormorant in Mississippi Alluvial Valley is projected to fall about 38% by 2029 — from 1.1 in 2024 to a central estimate of 0.66 (95% range 0.11–1.2). A 5-year backtest shows a typical error of ±54.8%, with 40% of held-out values landing inside the 95% band.

-38%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 →
0.66Projected 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 →
0.11–1.295% 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 →
±54.8%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 Mississippi Alluvial Valley is projected to fall about 38% by 2029 — from 1.1 in 2024 to a central estimate of 0.66 (95% range 0.11–1.2). A 5-year backtest shows a typical error of ±54.8%, with 40% of held-out values landing inside the 95% band.19902029
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 →
20250.600.051.2
20260.610.061.2
20270.630.081.2
20280.650.091.2
20290.660.111.2

Routes In Mississippi Alluvial Valley

Routes recording Double-crested Cormorant in Mississippi Alluvial Valley.
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 →
Eagle LakeMISSISSIPPI332024
MoonMISSISSIPPI142019
DundeeMISSISSIPPI102019
Pawpaw 2TENNESSEE102019
EnglandARKANSAS52011
IsolaMISSISSIPPI52021
Tchula 3MISSISSIPPI52023
HughesARKANSAS42018
AtchafalayaLOUISIANA41996
TiptonvilleTENNESSEE32021
BardwellKENTUCKY22003
BelairLOUISIANA22007
Morgan CityLOUISIANA22022
DeventerMISSOURI22021
South BendARKANSAS12015
Bardwell 2KENTUCKY12010
ShawLOUISIANA12009
RamahLOUISIANA12012
FrogmoreLOUISIANA12024
KraemerLOUISIANA12000
Port AllenLOUISIANA12011
River RoadLOUISIANA12024
Tensas NwrLOUISIANA12004
Baton RougeLOUISIANA12021
Delta N.F.MISSISSIPPI12015

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