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

Royal Tern Population Trend in Texas

All statesWetland birds

Royal Tern in Texas has surged: up 147% on the route-weighted index since 1976.

+147%Since 1976TrendPercent 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 →
13Routes 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 →
40YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Royal 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 →

No notable trend signals for Royal Tern in Texas. See the full index history below.

Royal Tern Population Forecast in Texas

If the recent trend holds, Royal Tern in Texas is projected to stay roughly flat through 2030, near 0.14 (95% range 0.01–0.27). A 5-year backtest shows a typical error of ±123.2%, with 80% of held-out values landing inside the 95% band.

n/aChange 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 →
0.14Projected 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 →
0.01–0.2795% 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 →
±123.2%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, Royal Tern in Texas is projected to stay roughly flat through 2030, near 0.14 (95% range 0.01–0.27). A 5-year backtest shows a typical error of ±123.2%, with 80% of held-out values landing inside the 95% band.19712030
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 →
20260.130.000.26
20270.130.010.26
20280.130.010.26
20290.140.010.26
20300.140.010.27

Royal Tern Survey Routes in Texas

Routes recording Royal 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 →
Padre Island Pais4120152015
Oyster Lake1120241995
Vanderbilt519751975
Bayside320032003
L. Atascosa Nwr220172017
Indianola220241979
Chinquapin220251995
Stowell220221976
Lag Atascosa120121971
Kingsville119761976
Winnie119941994
Danbury120232012
Bayside 3120252011

Royal Tern Population Trend in Other States

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