Species · Massachusetts · BBS 2025 Release · 1966–2024
Alder Flycatcher Population Trend in Massachusetts
Alder Flycatcher in Massachusetts has surged: up 737% on the route-weighted index since 1969.
+737%Since 1969
23Routes In State
57Years
Notable Alder Flycatcher Trends in Massachusetts
long arc increasecomputed index
Alder Flycatcher has surged in Massachusetts: up 737% on the route-weighted index since 1969.
Alder Flycatcher Population Forecast in Massachusetts
If the recent trend holds, Alder Flycatcher in Massachusetts is projected to fall about 27% by 2029 — from 1.5 in 2024 to a central estimate of 1.1 (95% range 0.56–1.6). A 5-year backtest shows a typical error of ±24.7%, with 100% of held-out values landing inside the 95% band.
-27%Change by 2029
1.1Projected 2029 index
0.56–1.695% range
±24.7%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 1.0 | 0.51 | 1.5 |
| 2026 | 1.0 | 0.52 | 1.6 |
| 2027 | 1.1 | 0.53 | 1.6 |
| 2028 | 1.1 | 0.54 | 1.6 |
| 2029 | 1.1 | 0.56 | 1.6 |
Alder Flycatcher Survey Routes in Massachusetts
| Chesterfield | 8 | 2024 | 1967 |
| Cummington | 7 | 2014 | 1968 |
| Monterey | 6 | 2024 | 2021 |
| Cummington 2 | 6 | 2024 | 2015 |
| Pittsfield | 3 | 2016 | 1972 |
| Warren | 2 | 2008 | 1979 |
| Wellfleet | 1 | 1987 | 1987 |
| Ware River | 1 | 2022 | 1993 |
| Newburyport | 1 | 2010 | 1994 |
| Maynard | 1 | 1994 | 1994 |
| Littleton | 1 | 2009 | 2007 |
| Princeton | 1 | 1976 | 1971 |
| E Pepperell | 1 | 1993 | 1976 |
| Belchertown | 1 | 2022 | 1976 |
| S Barre | 1 | 2024 | 1973 |
| N Orange | 1 | 2024 | 1969 |
| Cheshire | 1 | 1992 | 1969 |
| Sheffield | 1 | 2013 | 1973 |
| Gay Head | 1 | 2019 | 2002 |
| Wellfleet 2 | 1 | 2018 | 2018 |
| Holden | 1 | 2016 | 1986 |
| Warren 2 | 1 | 2018 | 2011 |
| Hancock | 1 | 2015 | 2001 |
Alder Flycatcher Population Trend in Other States
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.