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

Caspian Tern In Gulf Coastal Prairie

All regionsGulf Coastal PrairieWetland birds

Caspian Tern in Gulf Coastal Prairie has held roughly steady: up 3% on the route-weighted index since 1971.

+3%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 →
17Routes 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 →
42YearsYears 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 Caspian Tern in Gulf Coastal Prairie. See the full index history below.

Caspian Tern In Gulf Coastal Prairie Population Forecast

If the recent trend holds, Caspian Tern in Gulf Coastal Prairie is projected to fall about 24% by 2028 — from 0.87 in 2023 to a central estimate of 0.66 (95% range 0.00–1.5). A 5-year backtest shows a typical error of ±202.5%, with 100% of held-out values landing inside the 95% band.

-24%Change by 2028TrendPercent 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 →
0.66Projected 2028 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–1.595% 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 →
±202.5%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, Caspian Tern in Gulf Coastal Prairie is projected to fall about 24% by 2028 — from 0.87 in 2023 to a central estimate of 0.66 (95% range 0.00–1.5). A 5-year backtest shows a typical error of ±202.5%, with 100% of held-out values landing inside the 95% band.19672028
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 →
20240.640.001.4
20250.650.001.4
20260.650.001.4
20270.660.001.5
20280.660.001.5

Routes In Gulf Coastal Prairie

Routes recording Caspian 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 →
L. Atascosa NwrTEXAS122023
Padre Island PaisTEXAS92015
Bayside 3TEXAS82023
Ltl ChenierLOUISIANA72014
Gran ChenierLOUISIANA51973
Grand IsleLOUISIANA42018
IndianolaTEXAS22007
Oyster LakeTEXAS22019
Bayside 2TEXAS22004
McfaddinTEXAS22011
CreoleLOUISIANA11970
Sabine Nwr 2LOUISIANA12015
Lag AtascosaTEXAS12021
PetronilaTEXAS11976
DanburyTEXAS12009
ChinquapinTEXAS12015
BaysideTEXAS12010

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