Species · BCR 12 · BBS 2025 Release · 1966–2024
Caspian Tern In Boreal Hardwood Transition
Caspian Tern in Boreal Hardwood Transition has collapsed: down 90% on the route-weighted index since 1969.
-90%Since 1969
13Routes In Region
47Years
Notable Signals
long arc declinecomputed index
Caspian Tern has collapsed in Boreal Hardwood Transition: down 90% on the route-weighted index since 1969.
Forecast
If the recent trend holds, Caspian Tern in Boreal Hardwood Transition is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.16). A 5-year backtest shows a typical error of ±75.8%, with 100% of held-out values landing inside the 95% band.
n/aChange by 2029
0.00Projected 2029 index
0.00–0.1695% range
±75.8%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.00 | 0.00 | 0.16 |
| 2026 | 0.00 | 0.00 | 0.16 |
| 2027 | 0.00 | 0.00 | 0.16 |
| 2028 | 0.00 | 0.00 | 0.16 |
| 2029 | 0.00 | 0.00 | 0.16 |
Routes In Boreal Hardwood Transition
| Pine River | MINNESOTA | 7 | 1986 |
| Backus | MINNESOTA | 6 | 1992 |
| Seney Nwr | MICHIGAN | 3 | 2009 |
| Pleasant Valley 2 | MICHIGAN | 2 | 2004 |
| Herman | MICHIGAN | 1 | 1984 |
| Gilchrist | MICHIGAN | 1 | 2010 |
| Pleasant Val | MICHIGAN | 1 | 1994 |
| Riggsville | MICHIGAN | 1 | 2018 |
| Walloon Lake 2 | MICHIGAN | 1 | 2007 |
| Mayfield | MICHIGAN | 1 | 2014 |
| Mille Lacs | MINNESOTA | 1 | 1979 |
| Nebish | MINNESOTA | 1 | 1989 |
| Washington I | WISCONSIN | 1 | 2024 |
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.