Hammond's Flycatcher
Hammond's Flycatcher has surged: up 722% on the route-weighted index since 1970.
About the Hammond's Flycatcher
The Hammond's Flycatcher (Empidonax hammondii) 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 483 Breeding Bird Survey routes across 11 states, most concentrated in the Northern Rockies.
- Family
- Tyrannidae · Aerial insectivores
Notable Hammond's Flycatcher Trends
No notable trend signals for Hammond's Flycatcher. See the full index history below.
Hammond's Flycatcher Population Forecast
If the recent trend holds, Hammond's Flycatcher is projected to rise about 25% by 2029 — from 0.41 in 2024 to a central estimate of 0.52 (95% range 0.39–0.64). A 5-year backtest shows a typical error of ±33%, with 40% of held-out values landing inside the 95% band.
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.49 | 0.37 | 0.61 |
| 2026 | 0.50 | 0.37 | 0.62 |
| 2027 | 0.50 | 0.38 | 0.63 |
| 2028 | 0.51 | 0.39 | 0.64 |
| 2029 | 0.52 | 0.39 | 0.64 |
Where the Hammond's Flycatcher Is Detected
BBS routes recording Hammond's Flycatcher, sized by most recent count.
Hammond's Flycatcher Population Trend by State
| Alaska | +134% | 1987 | 44 |
| Arizona | insufficient data | n/a | 3 |
| California | +493% | 1970 | 76 |
| Colorado | +390% | 1974 | 69 |
| Idaho | +61% | 1978 | 38 |
| Montana | +351% | 1970 | 41 |
| New Mexico | +62% | 1973 | 10 |
| Oregon | +134% | 1970 | 85 |
| Utah | +234% | 1987 | 24 |
| Washington | +152% | 1970 | 71 |
| Wyoming | +637% | 1984 | 22 |
Hammond's Flycatcher Population Trend by Region
Bird Conservation Regions are the ecological unit for trends.
| BCR 4 | +225% | 1987 | 35 |
| Northern Pacific Rainforest | +127% | 1970 | 93 |
| Great Basin | +149% | 1970 | 76 |
| Northern Rockies | +230% | 1970 | 127 |
| Sierra Nevada | -25% | 1972 | 35 |
| Southern Rockies / Colorado Plateau | +544% | 1970 | 102 |
| Coastal California | +102% | 1982 | 7 |
Hammond's Flycatcher Conservation Status
Our route-weighted index shows it up about 722% since 1970. 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.