BirdAnalyst
Species · Texas · BBS 2026 Release · 1966–2025

Forster's Tern Population Trend in Texas

All statesWetland birds

Forster's Tern in Texas has surged: up 186% on the route-weighted index since 1970.

+186%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 →
25Routes 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 →
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 Forster's Tern 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 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 →

Forster's Tern has surged in Texas: up 186% on the route-weighted index since 1970.

Forster's Tern Population Forecast in Texas

If the recent trend holds, Forster's Tern in Texas is projected to fall about 26% by 2030 — from 0.50 in 2025 to a central estimate of 0.37 (95% range 0.00–0.80). A 5-year backtest shows a typical error of ±130.2%, with 100% of held-out values landing inside the 95% band.

-26%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 →
0.37Projected 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 →
0.00–0.8095% 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 →
±130.2%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, Forster's Tern in Texas is projected to fall about 26% by 2030 — from 0.50 in 2025 to a central estimate of 0.37 (95% range 0.00–0.80). A 5-year backtest shows a typical error of ±130.2%, with 100% of held-out values landing inside the 95% band.19672030
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 →
20260.360.000.79
20270.360.000.79
20280.360.000.80
20290.370.000.80
20300.370.000.80

Forster's Tern Survey Routes in Texas

Routes recording Forster's Tern 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 →
L. Atascosa Nwr4220251999
Oyster Lake2820251995
Zapata1619791979
Loyola Beach820051999
Bayside820101994
Port Acres820122003
Stowell620231969
Hinkles Fer520061979
Bayside 3520252005
Bayside 2420041997
Padre Island Pais320152015
Indianola320241967
Lag Atascosa220251971
Loyola Beach 2220222010
Winnie219891987
Progreso219941994
Raymondville220051975
Kingsville119781967
Petronila119921992
Danbury120241981
Rock Island119941994
Chinquapin120231995
Moon Lake120002000
Sadler120252025
Bonner120062006

Forster's Tern Population Trend in Other States

alabamacaliforniacoloradodelawarefloridageorgiaidahoillinoisindianaiowakansaslouisianamarylandmichiganminnesotamontananebraskanevadanew-jerseynew-yorknorth-carolinanorth-dakotaoregonsouth-carolinasouth-dakotautahvirginiawashingtonwisconsinwyoming

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