BirdAnalyst
Species · Texas · BBS 2025 Release · 1966–2024

Anhinga Population Trend in Texas

All statesGeneralists

Anhinga in Texas has fallen sharply: down 73% on the route-weighted index since 1970.

-73%Since 1970TrendPercent 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 →
40Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
56YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Anhinga Trends in TexasNotable 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 Texas: down 73% on the route-weighted index since 1970.

Anhinga Population Forecast in Texas

If the recent trend holds, Anhinga in Texas is projected to fall about 91% by 2029 — from 0.06 in 2024 to a central estimate of 0.01 (95% range 0.00–0.13). A 5-year backtest shows a typical error of ±96.5%, with 100% of held-out values landing inside the 95% band.

-91%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 →
0.01Projected 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 →
0.00–0.1395% 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 →
±96.5%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, Anhinga in Texas is projected to fall about 91% by 2029 — from 0.06 in 2024 to a central estimate of 0.01 (95% range 0.00–0.13). A 5-year backtest shows a typical error of ±96.5%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20250.010.000.14
20260.010.000.14
20270.010.000.13
20280.010.000.13
20290.010.000.13

Anhinga Survey Routes in Texas

Routes recording Anhinga in Texas.
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 →
Petronila819751975
Loyola Beach 2520222016
Kingsville320002000
Goliad Prairie320152011
Moon Lake 2320242019
Hinkles Fer220211968
New Waverly219801977
Massey Lake220241970
Crossroads219781978
Alexander St220212009
Bonner220172015
Oak Grove 2120212009
L. Atascosa Nwr120222022
Padre Island Pais120152015
Campbellton120102002
Cayuga120162005
Winnie120132003
Stowell120121996
Danbury120221992
Katy120241970
Rock Island120231979
Lockhart120032003
Town Bluff120241975
Livingston119771977
Oak Grove119841979

Anhinga Population Trend in Other States

alabamaarkansasfloridageorgialouisianamississippinorth-carolinaoklahomasouth-carolinavirginia

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