Species · BCR 10 · BBS 2025 Release · 1966–2024
Chestnut-collared Longspur In Northern Rockies
Chestnut-collared Longspur in Northern Rockies has collapsed: down 87% on the route-weighted index since 1971.
-87%Since 1971
8Routes In Region
38Years
Notable Signals
long arc declinecomputed index
Chestnut-collared Longspur has collapsed in Northern Rockies: down 87% on the route-weighted index since 1971.
Forecast
If the recent trend holds, Chestnut-collared Longspur in Northern Rockies is projected to stay roughly flat through 2027, near 0.00 (95% range 0.00–0.20). A 5-year backtest shows a typical error of ±104.4%, with 100% of held-out values landing inside the 95% band.
n/aChange by 2027
0.00Projected 2027 index
0.00–0.2095% range
±104.4%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2023 | 0.00 | 0.00 | 0.20 |
| 2024 | 0.00 | 0.00 | 0.20 |
| 2025 | 0.00 | 0.00 | 0.20 |
| 2026 | 0.00 | 0.00 | 0.20 |
| 2027 | 0.00 | 0.00 | 0.20 |
Routes In Northern Rockies
| Augusta | MONTANA | 3 | 2010 |
| Rawlins | WYOMING | 3 | 2005 |
| St Mary | MONTANA | 2 | 1980 |
| Rock River | WYOMING | 2 | 2022 |
| Twin Bridges | MONTANA | 1 | 1976 |
| Clark | WYOMING | 1 | 2011 |
| Ethete | WYOMING | 1 | 1992 |
| Baggs | WYOMING | 1 | 1995 |
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.