BirdAnalyst
Species · BCR 37 · BBS 2026 Release · 1966–2025

Neotropic Cormorant In Gulf Coastal Prairie

All regionsGulf Coastal PrairieWetland birds

Neotropic Cormorant in Gulf Coastal Prairie has surged: up 280% on the route-weighted index since 1971.

+280%Since 1971TrendPercent 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 →
36Routes 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 →
50YearsYears 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 →

Neotropic Cormorant has surged in Gulf Coastal Prairie: up 280% on the route-weighted index since 1971.

Neotropic Cormorant In Gulf Coastal Prairie Population Forecast

If the recent trend holds, Neotropic Cormorant in Gulf Coastal Prairie is projected to fall about 35% by 2030 — from 15 in 2025 to a central estimate of 10.0 (95% range 0.00–22). A 5-year backtest shows a typical error of ±103.7%, with 100% of held-out values landing inside the 95% band.

-35%Change by 2030TrendPercent 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 →
10.0Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–2295% 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 →
±103.7%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, Neotropic Cormorant in Gulf Coastal Prairie is projected to fall about 35% by 2030 — from 15 in 2025 to a central estimate of 10.0 (95% range 0.00–22). A 5-year backtest shows a typical error of ±103.7%, with 100% of held-out values landing inside the 95% band.19692030
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 →
20269.50.0022
20279.60.0022
20289.70.0022
20299.80.0022
203010.00.0022

Routes In Gulf Coastal Prairie

Routes recording Neotropic Cormorant in Gulf Coastal 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 →
Forked Island 2LOUISIANA3112011
Forked IslandLOUISIANA1032025
ChinquapinTEXAS1032025
RichardLOUISIANA512025
WoodlawnLOUISIANA482021
Sabine NwrLOUISIANA422008
Sabine Nwr 2LOUISIANA372017
MauriceLOUISIANA322024
Moon Lake 2TEXAS282025
CreoleLOUISIANA161980
Ltl Chenier 2LOUISIANA162011
L. Atascosa NwrTEXAS142025
EstherLOUISIANA132025
Vinton 2LOUISIANA132025
BaysideTEXAS122010
Gran ChenierLOUISIANA111982
Goliad PrairieTEXAS112016
Hinkles FerTEXAS92017
Bayside 2TEXAS92004
Loyola Beach 2TEXAS82024
KaplanLOUISIANA62023
WinnieTEXAS62017
DanburyTEXAS42025
Bayside 3TEXAS42025
StowellTEXAS32023

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.