Alder Flycatcher
Alder Flycatcher has surged: up 178% on the route-weighted index since 1968.
About the Alder Flycatcher
The Alder Flycatcher (Empidonax alnorum) is a North American member of the Tyrant Flycatchers (Tyrannidae). In this analysis it is grouped with the aerial insectivores.
- Size
- 4.5–9 in long (12–23 cm) — a small to medium flycatcher (typical for the family)
- Habitat
- Open airspace over fields, water and towns; nests in cavities, earthen banks or on structures.
- Diet
- Flying insects caught on the wing.
- Range
- Recorded on 786 Breeding Bird Survey routes across 26 states, most concentrated in the Atlantic Northern Forest.
- Family
- Tyrannidae · Aerial insectivores
Notable Alder Flycatcher Trends
Alder Flycatcher has surged in surveyed states: up 178% on the route-weighted index since 1968.
Alder Flycatcher Population Forecast
If the recent trend holds, Alder Flycatcher is projected to rise about 35% by 2029 — from 0.86 in 2024 to a central estimate of 1.2 (95% range 0.81–1.5). A 5-year backtest shows a typical error of ±32.7%, with 80% of held-out values landing inside the 95% band.
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 1.1 | 0.76 | 1.5 |
| 2026 | 1.1 | 0.78 | 1.5 |
| 2027 | 1.1 | 0.79 | 1.5 |
| 2028 | 1.2 | 0.80 | 1.5 |
| 2029 | 1.2 | 0.81 | 1.5 |
Where the Alder Flycatcher Is Detected
BBS routes recording Alder Flycatcher, sized by most recent count.
Alder Flycatcher Population Trend by State
| Alaska | -27% | 1975 | 114 |
| Connecticut | +66% | 1976 | 13 |
| Idaho | insufficient data | n/a | 1 |
| Illinois | insufficient data | n/a | 2 |
| Indiana | -53% | 1985 | 8 |
| Iowa | insufficient data | n/a | 2 |
| Maine | -45% | 1968 | 77 |
| Maryland | -21% | 1978 | 5 |
| Massachusetts | +737% | 1969 | 23 |
| Michigan | +224% | 1969 | 89 |
| Minnesota | +71% | 1969 | 62 |
| Montana | insufficient data | n/a | 6 |
| New Hampshire | +13% | 1968 | 26 |
| New Jersey | -10% | 1987 | 7 |
| New York | +612% | 1968 | 105 |
| North Carolina | insufficient data | n/a | 3 |
| North Dakota | -1% | 1981 | 13 |
| Ohio | -82% | 1975 | 16 |
| Oklahoma | insufficient data | n/a | 1 |
| Pennsylvania | +287% | 1973 | 78 |
| South Dakota | insufficient data | n/a | 1 |
| Vermont | +242% | 1968 | 25 |
| Virginia | insufficient data | n/a | 1 |
| Washington | insufficient data | n/a | 1 |
| West Virginia | +282% | 1980 | 16 |
| Wisconsin | +77% | 1968 | 91 |
Alder Flycatcher Population Trend by Region
Bird Conservation Regions are the ecological unit for trends.
| BCR 2 | -87% | 1993 | 17 |
| BCR 4 | -36% | 1976 | 68 |
| Northern Pacific Rainforest | -21% | 1984 | 26 |
| Prairie Potholes | -63% | 1977 | 24 |
| Boreal Hardwood Transition | +125% | 1968 | 121 |
| Lower Great Lakes / St. Lawrence Plain | +429% | 1969 | 69 |
| Atlantic Northern Forest | +55% | 1968 | 153 |
| Eastern Tallgrass Prairie | +63% | 1992 | 11 |
| Prairie Hardwood Transition | +35% | 1968 | 113 |
| Appalachian Mountains | +507% | 1970 | 133 |
| New England / Mid-Atlantic Coast | +95% | 1971 | 35 |
Alder Flycatcher Conservation Status
Our route-weighted index shows it up about 178% since 1968. Aerial insectivores have fallen sharply across the continent, a decline widely linked to dwindling insect prey.
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22. Trend is a route-weighted relative-abundance index, not an absolute population.