Species · BCR 15 · BBS 2025 Release · 1966–2024
Pied-billed Grebe In Sierra Nevada
Pied-billed Grebe in Sierra Nevada has fallen sharply: down 65% on the route-weighted index since 1975.
-65%Since 1975
12Routes In Region
38Years
Notable Signals
long arc declinecomputed index
Pied-billed Grebe has fallen sharply in Sierra Nevada: down 65% on the route-weighted index since 1975.
Forecast
If the recent trend holds, Pied-billed Grebe in Sierra Nevada is projected to rise about 50% by 2026 — from 0.06 in 2021 to a central estimate of 0.09 (95% range 0.00–0.36). A 5-year backtest shows a typical error of ±88.7%, with 100% of held-out values landing inside the 95% band.
+50%Change by 2026
0.09Projected 2026 index
0.00–0.3695% range
±88.7%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2022 | 0.10 | 0.00 | 0.37 |
| 2023 | 0.10 | 0.00 | 0.36 |
| 2024 | 0.10 | 0.00 | 0.36 |
| 2025 | 0.10 | 0.00 | 0.36 |
| 2026 | 0.09 | 0.00 | 0.36 |
Routes In Sierra Nevada
| Butte Meadow | CALIFORNIA | 2 | 1974 |
| Hat Creek | CALIFORNIA | 2 | 2018 |
| Eagle Lake | CALIFORNIA | 1 | 2019 |
| Tuolumne Grove | CALIFORNIA | 1 | 2021 |
| Sattley | CALIFORNIA | 1 | 2019 |
| Genesee | CALIFORNIA | 1 | 2012 |
| Higgins Corn | CALIFORNIA | 1 | 2003 |
| Chaos Crater | CALIFORNIA | 1 | 1994 |
| Goumaz | CALIFORNIA | 1 | 2011 |
| Paxton | CALIFORNIA | 1 | 2011 |
| Placerville | CALIFORNIA | 1 | 1999 |
| Last Chance | CALIFORNIA | 1 | 2019 |
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.