BirdAnalyst
Species · BCR 37 · BBS 2025 Release · 1966–2024

Common Tern In Gulf Coastal Prairie

All regionsGulf Coastal PrairieWetland birds

Common Tern in Gulf Coastal Prairie has edged up: up 24% on the route-weighted index since 1976.

+24%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 →
11Routes 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 →
23YearsYears 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 →

No notable trend signals for Common Tern in Gulf Coastal Prairie. See the full index history below.

Forecast

If the recent trend holds, Common Tern in Gulf Coastal Prairie is projected to stay roughly flat through 2023, near 0.12 (95% range 0.00–0.66). A 5-year backtest shows a typical error of ±264.1%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2023TrendPercent 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 →
0.12Projected 2023 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.6695% 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 →
±264.1%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, Common Tern in Gulf Coastal Prairie is projected to stay roughly flat through 2023, near 0.12 (95% range 0.00–0.66). A 5-year backtest shows a typical error of ±264.1%, with 100% of held-out values landing inside the 95% band.19712023
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 →
20190.140.000.68
20200.130.000.67
20210.130.000.67
20220.120.000.67
20230.120.000.66

Routes In Gulf Coastal Prairie

Routes recording Common Tern in Gulf Coastal Prairie.
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 →
Gran ChenierLOUISIANA111980
Padre Island PaisTEXAS92015
Sabine NwrLOUISIANA42001
CreoleLOUISIANA31979
WinnieTEXAS31979
StowellTEXAS21972
Grand IsleLOUISIANA12018
Ltl ChenierLOUISIANA12009
IndianolaTEXAS11971
Loyola BeachTEXAS11998
Bayside 2TEXAS12004

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