Species · Pennsylvania · BBS 2025 Release · 1966–2024
Common Merganser Population Trend in Pennsylvania
Common Merganser in Pennsylvania has surged: up 935% on the route-weighted index since 1978.
+935%Since 1978
54Routes In State
47Years
Notable Common Merganser Trends in Pennsylvania
long arc increasecomputed index
Common Merganser has surged in Pennsylvania: up 935% on the route-weighted index since 1978.
Common Merganser Population Forecast in Pennsylvania
If the recent trend holds, Common Merganser in Pennsylvania is projected to rise about 42% by 2029 — from 0.24 in 2024 to a central estimate of 0.33 (95% range 0.00–0.83). A 5-year backtest shows a typical error of ±79.4%, with 100% of held-out values landing inside the 95% band.
+42%Change by 2029
0.33Projected 2029 index
0.00–0.8395% range
±79.4%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.31 | 0.00 | 0.81 |
| 2026 | 0.32 | 0.00 | 0.82 |
| 2027 | 0.32 | 0.00 | 0.82 |
| 2028 | 0.33 | 0.00 | 0.83 |
| 2029 | 0.33 | 0.00 | 0.83 |
Common Merganser Survey Routes in Pennsylvania
| Berwick | 9 | 1993 | 1993 |
| Rush | 9 | 2024 | 2008 |
| Eldred | 8 | 2015 | 2004 |
| Pocono Summit | 8 | 2024 | 1997 |
| Ferris Crnrs | 5 | 2021 | 1997 |
| Susquehanna | 4 | 2023 | 2002 |
| Wyalusing | 3 | 2022 | 1988 |
| Lynch | 3 | 2019 | 1994 |
| Rasselas | 3 | 2014 | 2004 |
| Arnot | 3 | 2004 | 1994 |
| Waller | 3 | 2018 | 1998 |
| Kittanning | 3 | 2019 | 2009 |
| New Ringgold | 3 | 2012 | 2012 |
| Betula | 2 | 2019 | 1987 |
| Roulette | 2 | 2008 | 1999 |
| Ramsey | 2 | 2022 | 1995 |
| Mawr Glen | 2 | 2023 | 1983 |
| Bow Bridge | 2 | 2021 | 1989 |
| Poyntelle | 2 | 2006 | 1975 |
| Clearfield | 2 | 2005 | 1996 |
| Ellenton | 1 | 2024 | 2005 |
| Whig Hill | 1 | 2021 | 1985 |
| Sigel | 1 | 2023 | 2011 |
| N Washington | 1 | 2017 | 2015 |
| Starlight 2 | 1 | 2018 | 2018 |
Common Merganser Population Trend in Other States
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.