Species · Wisconsin · BBS 2025 Release · 1966–2024
Red-breasted Merganser Population Trend in Wisconsin
Red-breasted Merganser in Wisconsin has collapsed: down 90% on the route-weighted index since 1969.
-90%Since 1969
4Routes In State
27Years
Notable Red-breasted Merganser Trends in Wisconsin
long arc declinecomputed index
Red-breasted Merganser has collapsed in Wisconsin: down 89% on the route-weighted index since 1969.
Red-breasted Merganser Population Forecast in Wisconsin
If the recent trend holds, Red-breasted Merganser in Wisconsin is projected to stay roughly flat through 2016, near 0.00 (95% range 0.00–0.28). A 5-year backtest shows a typical error of ±499.6%, with 100% of held-out values landing inside the 95% band.
n/aChange by 2016
0.00Projected 2016 index
0.00–0.2895% range
±499.6%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2012 | 0.00 | 0.00 | 0.28 |
| 2013 | 0.00 | 0.00 | 0.28 |
| 2014 | 0.00 | 0.00 | 0.28 |
| 2015 | 0.00 | 0.00 | 0.28 |
| 2016 | 0.00 | 0.00 | 0.28 |
Red-breasted Merganser Survey Routes in Wisconsin
| Washington I | 2 | 2011 | 1967 |
| Casco | 1 | 2008 | 2008 |
| Wausaukee | 1 | 1983 | 1983 |
| Bayfield | 1 | 1999 | 1999 |
Red-breasted Merganser Population Trend in Other States
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.