BirdAnalyst
Species · BCR 25 · BBS 2025 Release · 1966–2024

Anhinga In West Gulf Coastal Plain / Ouachitas

All regionsWest Gulf Coastal Plain / OuachitasGeneralists

Anhinga in West Gulf Coastal Plain / Ouachitas has fallen sharply: down 73% on the route-weighted index since 1969.

-73%Since 1969TrendPercent 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 →
30Routes 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 →
54YearsYears 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 declinecomputed 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 →

Anhinga has fallen sharply in West Gulf Coastal Plain / Ouachitas: down 73% on the route-weighted index since 1969.

Anhinga In West Gulf Coastal Plain / Ouachitas Population Forecast

If the recent trend holds, Anhinga in West Gulf Coastal Plain / Ouachitas is projected to rise about 25% by 2029 — from 0.06 in 2024 to a central estimate of 0.07 (95% range 0.00–0.24). A 5-year backtest shows a typical error of ±33.8%, with 80% of held-out values landing inside the 95% band.

+25%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 →
0.07Projected 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 →
0.00–0.2495% 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 →
±33.8%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, Anhinga in West Gulf Coastal Plain / Ouachitas is projected to rise about 25% by 2029 — from 0.06 in 2024 to a central estimate of 0.07 (95% range 0.00–0.24). A 5-year backtest shows a typical error of ±33.8%, with 80% of held-out values landing inside the 95% band.19672029
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 →
20250.080.000.24
20260.080.000.24
20270.080.000.24
20280.070.000.24
20290.070.000.24

Routes In West Gulf Coastal Plain / Ouachitas

Routes recording Anhinga in West Gulf Coastal Plain / Ouachitas.
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 →
FillmoreLOUISIANA91987
GoodwaterOKLAHOMA72021
GoodwillLOUISIANA42016
HopeARKANSAS32000
EnterpriseLOUISIANA32019
Fishville 2LOUISIANA22019
NatchitochesLOUISIANA21989
EvelynLOUISIANA22022
New WaverlyTEXAS21980
CrossroadsTEXAS21978
Alexander StTEXAS22021
DerryLOUISIANA11973
CypressLOUISIANA11987
Mer RougeLOUISIANA12005
Flat CreekLOUISIANA12008
Mount UnionLOUISIANA12022
WomackLOUISIANA12009
Derry 2LOUISIANA12024
HaughtonLOUISIANA12014
Pine PrairieLOUISIANA11995
NatchezLOUISIANA12024
Lake CoveLOUISIANA12012
Town BluffTEXAS12024
LivingstonTEXAS11977
DibollTEXAS11990

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