Species · Wisconsin · BBS 2025 Release · 1966–2024
Black Tern Population Trend in Wisconsin
Black Tern in Wisconsin has collapsed: down 99% on the route-weighted index since 1968.
-99%Since 1968
42Routes In State
55Years
Notable Black Tern Trends in Wisconsin
long arc declinecomputed index
Black Tern has collapsed in Wisconsin: down 99% on the route-weighted index since 1968.
Black Tern Population Forecast in Wisconsin
If the recent trend holds, Black Tern in Wisconsin is projected to stay roughly flat through 2027, near 0.00 (95% range 0.00–0.56). A 5-year backtest shows a typical error of ±1284.4%, with 100% of held-out values landing inside the 95% band.
n/aChange by 2027
0.00Projected 2027 index
0.00–0.5695% range
±1284.4%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2023 | 0.00 | 0.00 | 0.56 |
| 2024 | 0.00 | 0.00 | 0.56 |
| 2025 | 0.00 | 0.00 | 0.56 |
| 2026 | 0.00 | 0.00 | 0.56 |
| 2027 | 0.00 | 0.00 | 0.56 |
Black Tern Survey Routes in Wisconsin
| Omro | 7 | 2001 | 1966 |
| Land O Lakes | 6 | 1981 | 1969 |
| Mount Horeb | 5 | 1986 | 1968 |
| Bashaw | 4 | 2004 | 2004 |
| Princeton | 4 | 1980 | 1967 |
| Union Twp | 3 | 2006 | 1972 |
| Weyerhauser | 3 | 1981 | 1966 |
| Minong | 2 | 1980 | 1967 |
| Hudson | 2 | 2003 | 1966 |
| Dresser | 2 | 2021 | 1966 |
| Loraine | 2 | 2016 | 1966 |
| Cumberland | 2 | 1988 | 1966 |
| Phillips | 2 | 1969 | 1969 |
| Irma | 2 | 1978 | 1968 |
| Hollister | 2 | 1967 | 1967 |
| Elderon | 2 | 2001 | 1966 |
| Oconto Falls | 2 | 2019 | 1968 |
| Pardeeville | 2 | 1996 | 1983 |
| Grand View | 1 | 1971 | 1971 |
| Couderay | 1 | 1980 | 1969 |
| Exeland | 1 | 1972 | 1968 |
| Gilman | 1 | 2003 | 1995 |
| Omro 2 | 1 | 2013 | 2002 |
| Eagle River | 1 | 1967 | 1967 |
| Popple River | 1 | 1992 | 1967 |
Black Tern Population Trend in Other States
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.