Olive-sided Flycatcher
Olive-sided Flycatcher has surged: up 171% on the route-weighted index since 1968.
About the Olive-sided Flycatcher
The Olive-sided Flycatcher (Contopus cooperi) 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 961 Breeding Bird Survey routes across 26 states, most concentrated in the Northern Pacific Rainforest.
- Family
- Tyrannidae · Aerial insectivores
Notable Olive-sided Flycatcher Trends
Olive-sided Flycatcher has surged in surveyed states: up 171% on the route-weighted index since 1968.
Olive-sided Flycatcher Population Forecast
If the recent trend holds, Olive-sided Flycatcher is projected to stay roughly flat through 2029, near 0.33 (95% range 0.14–0.52). A 5-year backtest shows a typical error of ±26.3%, with 100% of held-out values landing inside the 95% band.
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.34 | 0.14 | 0.53 |
| 2026 | 0.33 | 0.14 | 0.53 |
| 2027 | 0.33 | 0.14 | 0.53 |
| 2028 | 0.33 | 0.14 | 0.52 |
| 2029 | 0.33 | 0.14 | 0.52 |
Where the Olive-sided Flycatcher Is Detected
BBS routes recording Olive-sided Flycatcher, sized by most recent count.
Olive-sided Flycatcher Population Trend by State
| Alaska | +107% | 1975 | 91 |
| Arizona | +31% | 1973 | 19 |
| California | -56% | 1970 | 158 |
| Colorado | -40% | 1970 | 79 |
| Idaho | +76% | 1972 | 34 |
| Maine | -90% | 1969 | 68 |
| Maryland | insufficient data | n/a | 1 |
| Massachusetts | insufficient data | n/a | 4 |
| Michigan | -26% | 1968 | 36 |
| Minnesota | -31% | 1970 | 45 |
| Montana | +16% | 1970 | 42 |
| Nevada | insufficient data | n/a | 4 |
| New Hampshire | -90% | 1968 | 21 |
| New Mexico | +42% | 1972 | 15 |
| New York | -66% | 1968 | 26 |
| North Carolina | insufficient data | n/a | 1 |
| Ohio | insufficient data | n/a | 1 |
| Oregon | -74% | 1970 | 99 |
| Pennsylvania | insufficient data | n/a | 7 |
| South Dakota | insufficient data | n/a | 1 |
| Utah | -77% | 1981 | 43 |
| Vermont | -75% | 1969 | 20 |
| Washington | -59% | 1970 | 76 |
| West Virginia | insufficient data | n/a | 1 |
| Wisconsin | -81% | 1968 | 41 |
| Wyoming | +93% | 1978 | 28 |
Olive-sided Flycatcher Population Trend by Region
Bird Conservation Regions are the ecological unit for trends.
| BCR 4 | +50% | 1982 | 60 |
| Northern Pacific Rainforest | -77% | 1970 | 149 |
| Great Basin | -36% | 1970 | 86 |
| Northern Rockies | -13% | 1970 | 126 |
| Boreal Hardwood Transition | -39% | 1968 | 98 |
| Atlantic Northern Forest | -91% | 1968 | 128 |
| Sierra Nevada | -80% | 1970 | 38 |
| Southern Rockies / Colorado Plateau | -14% | 1970 | 131 |
| Prairie Hardwood Transition | -29% | 1970 | 20 |
| Coastal California | -56% | 1970 | 64 |
| Sonoran and Mojave Deserts | -34% | 1974 | 3 |
| Sierra Madre Occidental | -56% | 1974 | 18 |
Olive-sided Flycatcher Conservation Status
Our route-weighted index shows it up about 171% 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.