Least Flycatcher
Least Flycatcher has fallen sharply: down 55% on the route-weighted index since 1968.
About the Least Flycatcher
The Least Flycatcher (Empidonax minimus) 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 1,185 Breeding Bird Survey routes across 38 states, most concentrated in the Appalachian Mountains.
- Family
- Tyrannidae · Aerial insectivores
Notable Least Flycatcher Trends
Least Flycatcher has fallen sharply in surveyed states: down 55% on the route-weighted index since 1968.
Least Flycatcher Population Forecast
If the recent trend holds, Least Flycatcher is projected to fall about 37% by 2029 — from 0.63 in 2024 to a central estimate of 0.39 (95% range 0.19–0.60). A 5-year backtest shows a typical error of ±27.6%, with 60% of held-out values landing inside the 95% band.
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.46 | 0.25 | 0.66 |
| 2026 | 0.44 | 0.23 | 0.65 |
| 2027 | 0.42 | 0.22 | 0.63 |
| 2028 | 0.41 | 0.20 | 0.61 |
| 2029 | 0.39 | 0.19 | 0.60 |
Where the Least Flycatcher Is Detected
BBS routes recording Least Flycatcher, sized by most recent count.
Least Flycatcher Population Trend by State
| Alaska | -23% | 1993 | 9 |
| Arkansas | insufficient data | n/a | 1 |
| California | insufficient data | n/a | 1 |
| Colorado | insufficient data | n/a | 3 |
| Connecticut | -84% | 1968 | 20 |
| Georgia | insufficient data | n/a | 2 |
| Idaho | +170% | 1991 | 14 |
| Illinois | -82% | 1970 | 30 |
| Indiana | -75% | 1971 | 19 |
| Iowa | -4% | 1970 | 23 |
| Kentucky | insufficient data | n/a | 2 |
| Maine | -60% | 1968 | 78 |
| Maryland | -75% | 1968 | 14 |
| Massachusetts | -25% | 1968 | 26 |
| Michigan | +2% | 1968 | 103 |
| Minnesota | +25% | 1969 | 86 |
| Missouri | insufficient data | n/a | 1 |
| Montana | +821% | 1971 | 79 |
| Nebraska | insufficient data | n/a | 4 |
| New Hampshire | -79% | 1968 | 26 |
| New Jersey | -52% | 1969 | 14 |
| New York | -63% | 1968 | 122 |
| North Carolina | -72% | 1975 | 14 |
| North Dakota | +257% | 1969 | 51 |
| Ohio | -67% | 1968 | 40 |
| Oregon | insufficient data | n/a | 2 |
| Pennsylvania | -41% | 1968 | 111 |
| Rhode Island | -91% | 1968 | 4 |
| South Carolina | insufficient data | n/a | 1 |
| South Dakota | +157% | 1969 | 32 |
| Tennessee | +58% | 1969 | 7 |
| Utah | insufficient data | n/a | 2 |
| Vermont | -46% | 1968 | 26 |
| Virginia | -69% | 1970 | 25 |
| Washington | -37% | 1986 | 16 |
| West Virginia | +573% | 1968 | 46 |
| Wisconsin | -29% | 1968 | 97 |
| Wyoming | +110% | 1977 | 34 |
Least Flycatcher Population Trend by Region
Bird Conservation Regions are the ecological unit for trends.
| Northern Pacific Rainforest | +178% | 1995 | 5 |
| Great Basin | -55% | 1990 | 17 |
| Northern Rockies | +590% | 1972 | 78 |
| Prairie Potholes | +193% | 1969 | 95 |
| Boreal Hardwood Transition | -20% | 1968 | 127 |
| Lower Great Lakes / St. Lawrence Plain | -61% | 1968 | 83 |
| Atlantic Northern Forest | -67% | 1968 | 156 |
| Southern Rockies / Colorado Plateau | -69% | 1994 | 5 |
| Badlands and Prairies | +380% | 1969 | 69 |
| Eastern Tallgrass Prairie | -71% | 1969 | 66 |
| Prairie Hardwood Transition | -27% | 1968 | 143 |
| Appalachian Mountains | -45% | 1968 | 257 |
| Piedmont | -85% | 1969 | 18 |
| New England / Mid-Atlantic Coast | -85% | 1968 | 52 |
Least Flycatcher Conservation Status
Our route-weighted index shows it down about 55% 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.