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

Least Tern Population Trend in Texas

All statesWetland birds

Least Tern in Texas has surged: up 178% on the route-weighted index since 1971.

+178%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 →
22Routes 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 →
45YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Least 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 →

Least Tern has surged in Texas: up 178% on the route-weighted index since 1971.

Least Tern Population Forecast in Texas

If the recent trend holds, Least Tern in Texas is projected to rise about 26% by 2029 — from 0.10 in 2024 to a central estimate of 0.13 (95% range 0.00–0.26). A 5-year backtest shows a typical error of ±23.2%, with 100% of held-out values landing inside the 95% band.

+26%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 →
0.13Projected 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 →
0.00–0.2695% 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 →
±23.2%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, Least Tern in Texas is projected to rise about 26% by 2029 — from 0.10 in 2024 to a central estimate of 0.13 (95% range 0.00–0.26). A 5-year backtest shows a typical error of ±23.2%, with 100% 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 →
20250.120.000.26
20260.130.000.26
20270.130.000.26
20280.130.000.26
20290.130.000.26

Least Tern Survey Routes in Texas

Routes recording Least 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 →
Oyster Lake1620241995
Bayside 2920041997
Kingsville819791974
Bayside 3720162005
L. Atascosa Nwr620231998
Padre Island Pais520152015
Stowell420231978
Loyola Beach320081999
Lag Atascosa219851976
Indianola220141967
Loyola Beach 2220212010
Winnie219971997
Bonner220162016
Gambill Ref.220231995
Danbury120091987
Chinquapin120061996
Bayside120102002
Port Acres120042004
Quitman Cyn.120002000
Weinert119901988
Clarendon119691969
Raymondville120021992

Least Tern Population Trend in Other States

alabamaarkansascaliforniacoloradodelawarefloridageorgiaillinoiskansaskentuckylouisianamainemarylandmassachusettsmississippimissourinebraskanew-jerseynew-yorknorth-carolinaoklahomasouth-carolinatennesseevirginia

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