Species · Louisiana · BBS 2025 Release · 1966–2024
Common Tern Population Trend in Louisiana
Common Tern in Louisiana has fallen sharply: down 63% on the route-weighted index since 1979.
-63%Since 1979
5Routes In State
20Years
Notable Common Tern Trends in Louisiana
long arc declinecomputed index
Common Tern has fallen sharply in Louisiana: down 63% on the route-weighted index since 1979.
Common Tern Population Forecast in Louisiana
If the recent trend holds, Common Tern in Louisiana is projected to stay roughly flat through 2023, near 0.00 (95% range 0.00–0.36). A 5-year backtest shows a typical error of ±101.7%, with 100% of held-out values landing inside the 95% band.
n/aChange by 2023
0.00Projected 2023 index
0.00–0.3695% range
±101.7%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2019 | 0.01 | 0.00 | 0.36 |
| 2020 | 0.00 | 0.00 | 0.36 |
| 2021 | 0.00 | 0.00 | 0.36 |
| 2022 | 0.00 | 0.00 | 0.36 |
| 2023 | 0.00 | 0.00 | 0.36 |
Common Tern Survey Routes in Louisiana
| Gran Chenier | 11 | 1980 | 1976 |
| Sabine Nwr | 4 | 2001 | 1992 |
| Creole | 3 | 1979 | 1978 |
| Grand Isle | 1 | 2018 | 2011 |
| Ltl Chenier | 1 | 2009 | 1988 |
Common Tern Population Trend in Other States
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.