Species · North Carolina · BBS 2025 Release · 1966–2024
Gull-billed Tern Population Trend in North Carolina
Gull-billed Tern in North Carolina has collapsed: down 90% on the route-weighted index since 1968.
-90%Since 1968
5Routes In State
25Years
Notable Gull-billed Tern Trends in North Carolina
long arc declinecomputed index
Gull-billed Tern has collapsed in North Carolina: down 90% on the route-weighted index since 1968.
Gull-billed Tern Population Forecast in North Carolina
If the recent trend holds, Gull-billed Tern in North Carolina is projected to stay roughly flat through 2022, near 0.00 (95% range 0.00–0.37). A 5-year backtest shows a typical error of ±810.1%, with 100% of held-out values landing inside the 95% band.
n/aChange by 2022
0.00Projected 2022 index
0.00–0.3795% range
±810.1%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2018 | 0.00 | 0.00 | 0.37 |
| 2019 | 0.00 | 0.00 | 0.37 |
| 2020 | 0.00 | 0.00 | 0.37 |
| 2021 | 0.00 | 0.00 | 0.37 |
| 2022 | 0.00 | 0.00 | 0.37 |
Gull-billed Tern Survey Routes in North Carolina
| Mashoes | 2 | 1974 | 1972 |
| Ernul | 2 | 2003 | 2003 |
| Merrimon | 1 | 2016 | 1968 |
| Myrtle Grove | 1 | 2017 | 1966 |
| Grandy | 1 | 1971 | 1971 |
Gull-billed Tern Population Trend in Other States
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.