Species · BCR 18 · BBS 2025 Release · 1966–2024
Brewer's Blackbird In Shortgrass Prairie
Brewer's Blackbird in Shortgrass Prairie has collapsed: down 88% on the route-weighted index since 1970.
-88%Since 1970
61Routes In Region
55Years
Notable Signals
long arc declinecomputed index
Brewer's Blackbird has collapsed in Shortgrass Prairie: down 88% on the route-weighted index since 1970.
Forecast
If the recent trend holds, Brewer's Blackbird in Shortgrass Prairie is projected to fall about 31% by 2029 — from 0.29 in 2024 to a central estimate of 0.20 (95% range 0.00–4.0). A 5-year backtest shows a typical error of ±37.2%, with 100% of held-out values landing inside the 95% band.
-31%Change by 2029
0.20Projected 2029 index
0.00–4.095% range
±37.2%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.46 | 0.00 | 4.2 |
| 2026 | 0.39 | 0.00 | 4.1 |
| 2027 | 0.33 | 0.00 | 4.1 |
| 2028 | 0.26 | 0.00 | 4.0 |
| 2029 | 0.20 | 0.00 | 4.0 |
Routes In Shortgrass Prairie
| Briggsdale | COLORADO | 35 | 2008 |
| Kiowa | COLORADO | 29 | 2018 |
| Berea | NEBRASKA | 18 | 2017 |
| Elbert | COLORADO | 11 | 2024 |
| Kiowa 2 | COLORADO | 10 | 2023 |
| Crawford | NEBRASKA | 9 | 2019 |
| Pine Ridge | NEBRASKA | 8 | 2002 |
| Gilpin | COLORADO | 7 | 1984 |
| Bennett | COLORADO | 7 | 2017 |
| Prospect Val | COLORADO | 6 | 2000 |
| Neegrande | COLORADO | 6 | 2019 |
| Nunn | COLORADO | 6 | 2006 |
| Murray Lake | NEBRASKA | 6 | 2024 |
| Wagon Mound | NEW-MEXICO | 6 | 1971 |
| Cooley Lake | NEW-MEXICO | 6 | 1976 |
| Pinneo | COLORADO | 5 | 1977 |
| Abarr | COLORADO | 5 | 2023 |
| Adams Co. | COLORADO | 5 | 2022 |
| Villegreen | COLORADO | 5 | 2000 |
| Hardesty | OKLAHOMA | 5 | 1988 |
| Yoder | WYOMING | 5 | 2023 |
| Pine Bluff | WYOMING | 5 | 2023 |
| Two Buttes | COLORADO | 4 | 2013 |
| Wildhorse L | COLORADO | 4 | 2015 |
| Edison | COLORADO | 4 | 2024 |
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.