Species · Alabama · BBS 2025 Release · 1966–2024
Gull-billed Tern Population Trend in Alabama
Gull-billed Tern in Alabama has collapsed: down 94% on the route-weighted index since 1985.
-94%Since 1985
4Routes In State
23Years
Notable Gull-billed Tern Trends in Alabama
long arc declinecomputed index
Gull-billed Tern has collapsed in Alabama: down 94% on the route-weighted index since 1985.
Gull-billed Tern Population Forecast in Alabama
If the recent trend holds, Gull-billed Tern in Alabama is projected to stay roughly flat through 2023, near 0.00 (95% range 0.00–0.26). A 5-year backtest shows a typical error of ±642.6%, with 100% of held-out values landing inside the 95% band.
n/aChange by 2023
0.00Projected 2023 index
0.00–0.2695% range
±642.6%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2019 | 0.00 | 0.00 | 0.26 |
| 2020 | 0.00 | 0.00 | 0.26 |
| 2021 | 0.00 | 0.00 | 0.26 |
| 2022 | 0.00 | 0.00 | 0.26 |
| 2023 | 0.00 | 0.00 | 0.26 |
Gull-billed Tern Survey Routes in Alabama
| Dauphin Is | 11 | 1990 | 1981 |
| Bon Secour | 3 | 1995 | 1995 |
| Alabama Pt | 2 | 1992 | 1992 |
| Dauphin Is 2 | 1 | 2018 | 1991 |
Gull-billed Tern Population Trend in Other States
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.