Vaux's Swift
Vaux's Swift has surged: up 203% on the route-weighted index since 1970.
About the Vaux's Swift
The Vaux's Swift (Chaetura vauxi) is a North American member of the Swifts (Apodidae). In this analysis it is grouped with the aerial insectivores.
- Size
- 4.5–7 in long (12–18 cm) — a small aerial bird (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 253 Breeding Bird Survey routes across 6 states, most concentrated in the Northern Pacific Rainforest.
- Family
- Apodidae · Aerial insectivores
Notable Vaux's Swift Trends
No notable trend signals for Vaux's Swift. See the full index history below.
Vaux's Swift Population Forecast
If the recent trend holds, Vaux's Swift is projected to stay roughly flat through 2029, near 0.06 (95% range 0.02–0.10). A 5-year backtest shows a typical error of ±64.2%, with 100% of held-out values landing inside the 95% band.
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.06 | 0.02 | 0.10 |
| 2026 | 0.06 | 0.02 | 0.10 |
| 2027 | 0.06 | 0.02 | 0.10 |
| 2028 | 0.06 | 0.02 | 0.10 |
| 2029 | 0.06 | 0.02 | 0.10 |
Where the Vaux's Swift Is Detected
BBS routes recording Vaux's Swift, sized by most recent count.
Vaux's Swift Population Trend by State
| Alaska | insufficient data | n/a | 5 |
| California | -37% | 1971 | 60 |
| Idaho | -76% | 1978 | 20 |
| Montana | -41% | 1982 | 14 |
| Oregon | +26% | 1970 | 83 |
| Washington | +53% | 1970 | 71 |
Vaux's Swift Population Trend by Region
Bird Conservation Regions are the ecological unit for trends.
| Northern Pacific Rainforest | -37% | 1970 | 94 |
| Great Basin | +223% | 1970 | 57 |
| Northern Rockies | -49% | 1974 | 69 |
| Sierra Nevada | -65% | 1975 | 14 |
| Coastal California | +34% | 1977 | 18 |
Vaux's Swift Conservation Status
Our route-weighted index shows it up about 203% 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.