Species · Idaho · BBS 2025 Release · 1966–2024
Caspian Tern Population Trend in Idaho
Caspian Tern in Idaho has collapsed: down 81% on the route-weighted index since 1986.
-81%Since 1986
9Routes In State
20Years
Notable Caspian Tern Trends in Idaho
long arc declinecomputed index
Caspian Tern has collapsed in Idaho: down 81% on the route-weighted index since 1986.
Caspian Tern Population Forecast in Idaho
If the recent trend holds, Caspian Tern in Idaho is projected to stay roughly flat through 2028, near 0.00 (95% range 0.00–0.09). A 5-year backtest shows a typical error of ±53.9%, with 100% of held-out values landing inside the 95% band.
n/aChange by 2028
0.00Projected 2028 index
0.00–0.0995% range
±53.9%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2024 | 0.00 | 0.00 | 0.10 |
| 2025 | 0.00 | 0.00 | 0.10 |
| 2026 | 0.00 | 0.00 | 0.09 |
| 2027 | 0.00 | 0.00 | 0.09 |
| 2028 | 0.00 | 0.00 | 0.09 |
Caspian Tern Survey Routes in Idaho
| Kyle Canyon | 3 | 1986 | 1986 |
| Acequia | 2 | 2002 | 2002 |
| Featherville | 2 | 2003 | 2000 |
| Cedar Hill | 1 | 2023 | 1998 |
| Preston | 1 | 2008 | 1992 |
| Cascade | 1 | 1984 | 1984 |
| Springfield | 1 | 2016 | 1973 |
| Picabo | 1 | 2005 | 1996 |
| Pasadena Val | 1 | 2010 | 1987 |
Caspian Tern Population Trend in Other States
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.