Species · Washington · BBS 2025 Release · 1966–2024
Gadwall Population Trend in Washington
Gadwall in Washington has increased: up 40% on the route-weighted index since 1975.
+40%Since 1975
30Routes In State
47Years
Notable Gadwall Trends in Washington
No notable trend signals for Gadwall in Washington. See the full index history below.
Gadwall Population Forecast in Washington
If the recent trend holds, Gadwall in Washington is projected to rise about 879% by 2029 — from 0.05 in 2024 to a central estimate of 0.52 (95% range 0.00–1.1). A 5-year backtest shows a typical error of ±403.4%, with 80% of held-out values landing inside the 95% band.
+879%Change by 2029
0.52Projected 2029 index
0.00–1.195% range
±403.4%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.50 | 0.00 | 1.1 |
| 2026 | 0.51 | 0.00 | 1.1 |
| 2027 | 0.51 | 0.00 | 1.1 |
| 2028 | 0.51 | 0.00 | 1.1 |
| 2029 | 0.52 | 0.00 | 1.1 |
Gadwall Survey Routes in Washington
| Brewster | 35 | 2018 | 1983 |
| Columbia Nwr | 34 | 2021 | 1992 |
| Othello | 13 | 1991 | 1984 |
| Rimrock | 5 | 2015 | 2015 |
| Wilbur | 5 | 2022 | 1984 |
| Mesa | 4 | 1997 | 1997 |
| Turnbull Nwr | 3 | 2018 | 1993 |
| Moses Lake | 3 | 2015 | 1973 |
| Scootney Reservoir | 3 | 2009 | 2009 |
| Keystone | 3 | 2024 | 1994 |
| Port Angeles | 2 | 2010 | 2006 |
| Chewelah | 2 | 1991 | 1991 |
| Deception | 2 | 1997 | 1996 |
| Cusick | 2 | 2023 | 1996 |
| Nighthawk | 2 | 2019 | 2011 |
| Moses Coulee | 2 | 2023 | 1996 |
| Odessa | 2 | 2022 | 2001 |
| Warm Beach | 1 | 2002 | 1999 |
| Hanford Site | 1 | 1989 | 1989 |
| L Pend O Nwr | 1 | 2022 | 2014 |
| Harrington | 1 | 1984 | 1981 |
| Reardan | 1 | 2018 | 1968 |
| Horn Rapids | 1 | 2016 | 2012 |
| Malden | 1 | 2004 | 2001 |
| Potholes | 1 | 2019 | 1996 |
Gadwall Population Trend in Other States
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.