BirdAnalyst
Species · BCR 37 · BBS 2025 Release · 1966–2024

Neotropic Cormorant In Gulf Coastal Prairie

All regionsGulf Coastal PrairieWetland birds

Neotropic Cormorant in Gulf Coastal Prairie has surged: up 142% on the route-weighted index since 1971.

+142%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 →
35Routes 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 →

Neotropic Cormorant has surged in Gulf Coastal Prairie: up 142% 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 rise about 142% by 2029 — from 3.9 in 2024 to a central estimate of 9.3 (95% range 0.00–21). A 5-year backtest shows a typical error of ±105.5%, with 100% of held-out values landing inside the 95% band.

+142%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 →
9.3Projected 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 →
0.00–2195% 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 →
±105.5%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 rise about 142% by 2029 — from 3.9 in 2024 to a central estimate of 9.3 (95% range 0.00–21). A 5-year backtest shows a typical error of ±105.5%, 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 →
20258.90.0021
20269.00.0021
20279.10.0021
20289.20.0021
20299.30.0021

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
WoodlawnLOUISIANA482021
Sabine NwrLOUISIANA422008
Sabine Nwr 2LOUISIANA372017
MauriceLOUISIANA322024
L. Atascosa NwrTEXAS172023
CreoleLOUISIANA161980
Ltl Chenier 2LOUISIANA162011
RichardLOUISIANA152024
EstherLOUISIANA132024
BaysideTEXAS122010
Gran ChenierLOUISIANA111982
Forked IslandLOUISIANA112024
Goliad PrairieTEXAS112016
Hinkles FerTEXAS92017
Bayside 2TEXAS92004
Loyola Beach 2TEXAS82024
KaplanLOUISIANA62023
WinnieTEXAS62017
Rock IslandTEXAS52021
StowellTEXAS32023
HackberryLOUISIANA22016
Vinton 2LOUISIANA22019
Lag AtascosaTEXAS22009
IndianolaTEXAS22009

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