Species · BCR 32 · BBS 2025 Release · 1966–2024
American Bittern In Coastal California
American Bittern in Coastal California has declined: down 34% on the route-weighted index since 1972.
-34%Since 1972
22Routes In Region
51Years
Notable Signals
No notable trend signals for American Bittern in Coastal California. See the full index history below.
Forecast
If the recent trend holds, American Bittern in Coastal California is projected to stay roughly flat through 2029, near 0.33 (95% range 0.00–0.99). A 5-year backtest shows a typical error of ±1210.5%, with 100% of held-out values landing inside the 95% band.
n/aChange by 2029
0.33Projected 2029 index
0.00–0.9995% range
±1210.5%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.35 | 0.00 | 1.0 |
| 2026 | 0.34 | 0.00 | 1.00 |
| 2027 | 0.34 | 0.00 | 0.99 |
| 2028 | 0.34 | 0.00 | 0.99 |
| 2029 | 0.33 | 0.00 | 0.99 |
Routes In Coastal California
| Glenn | CALIFORNIA | 13 | 2023 |
| Cordova | CALIFORNIA | 3 | 1975 |
| Pennington | CALIFORNIA | 2 | 2014 |
| Arvin | CALIFORNIA | 2 | 1985 |
| Tranquillity | CALIFORNIA | 2 | 2003 |
| Ora Loma | CALIFORNIA | 2 | 1983 |
| Athlone | CALIFORNIA | 2 | 1982 |
| Red Bluff | CALIFORNIA | 1 | 2014 |
| Collegeville | CALIFORNIA | 1 | 1979 |
| Hughson | CALIFORNIA | 1 | 1987 |
| Oilfields | CALIFORNIA | 1 | 1968 |
| Gravesboro | CALIFORNIA | 1 | 1985 |
| Orland | CALIFORNIA | 1 | 2015 |
| Creston | CALIFORNIA | 1 | 2002 |
| Shafter | CALIFORNIA | 1 | 1986 |
| Atwater | CALIFORNIA | 1 | 2007 |
| Gold Hill | CALIFORNIA | 1 | 1986 |
| Oroville | CALIFORNIA | 1 | 2008 |
| Tehama | CALIFORNIA | 1 | 1988 |
| Yolla Bolly | CALIFORNIA | 1 | 1997 |
| Zamora | CALIFORNIA | 1 | 1988 |
| Staten Is. | CALIFORNIA | 1 | 2024 |
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.