Species · BCR 10 · BBS 2025 Release · 1966–2024
Forster's Tern In Northern Rockies
Forster's Tern in Northern Rockies has fallen sharply: down 55% on the route-weighted index since 1981.
-55%Since 1981
16Routes In Region
39Years
Notable Signals
long arc declinecomputed index
Forster's Tern has fallen sharply in Northern Rockies: down 55% on the route-weighted index since 1981.
Forecast
If the recent trend holds, Forster's Tern in Northern Rockies is projected to stay roughly flat through 2029, near 0.04 (95% range 0.00–0.11). A 5-year backtest shows a typical error of ±182%, with 100% of held-out values landing inside the 95% band.
n/aChange by 2029
0.04Projected 2029 index
0.00–0.1195% range
±182%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.04 | 0.00 | 0.12 |
| 2026 | 0.04 | 0.00 | 0.12 |
| 2027 | 0.04 | 0.00 | 0.12 |
| 2028 | 0.04 | 0.00 | 0.11 |
| 2029 | 0.04 | 0.00 | 0.11 |
Routes In Northern Rockies
| Neponset Res | UTAH | 7 | 2018 |
| Midvale | WYOMING | 6 | 1996 |
| Red Rock | MONTANA | 4 | 1994 |
| Randolph | UTAH | 3 | 2024 |
| Kalispell | MONTANA | 2 | 1990 |
| Augusta | MONTANA | 2 | 1982 |
| Pablo Res. | MONTANA | 2 | 2012 |
| Alpine | WYOMING | 2 | 1999 |
| Centerville | IDAHO | 1 | 2011 |
| Crane Creek | IDAHO | 1 | 1989 |
| Featherville | IDAHO | 1 | 2010 |
| Saleratus Cr | UTAH | 1 | 2003 |
| Nowood | WYOMING | 1 | 2000 |
| Fontenelle | WYOMING | 1 | 2017 |
| Harmony | WYOMING | 1 | 2023 |
| Seedskadee | WYOMING | 1 | 2014 |
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.