Cave Swallow
Cave Swallow has surged: up 550% on the route-weighted index since 1980.
About the Cave Swallow
The Cave Swallow (Petrochelidon fulva) is a North American member of the Swallows & Martins (Hirundinidae). In this analysis it is grouped with the aerial insectivores.
- Size
- 4.5–8 in long (12–20 cm) — a small, streamlined 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 155 Breeding Bird Survey routes across 4 states, most concentrated in the Oaks and Prairies.
- Family
- Hirundinidae · Aerial insectivores
Notable Cave Swallow Trends
No notable trend signals for Cave Swallow. See the full index history below.
Cave Swallow Population Forecast
If the recent trend holds, Cave Swallow is projected to rise about 74% by 2029 — from 0.33 in 2024 to a central estimate of 0.56 (95% range 0.27–0.86). A 5-year backtest shows a typical error of ±190%, with 0% of held-out values landing inside the 95% band.
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.54 | 0.24 | 0.83 |
| 2026 | 0.55 | 0.25 | 0.84 |
| 2027 | 0.55 | 0.26 | 0.85 |
| 2028 | 0.56 | 0.26 | 0.85 |
| 2029 | 0.56 | 0.27 | 0.86 |
Where the Cave Swallow Is Detected
BBS routes recording Cave Swallow, sized by most recent count.
Cave Swallow Population Trend by State
| Louisiana | 21× | 2013 | 15 |
| New Mexico | insufficient data | n/a | 2 |
| Oklahoma | insufficient data | n/a | 1 |
| Texas | +410% | 1980 | 137 |
Cave Swallow Population Trend by Region
Bird Conservation Regions are the ecological unit for trends.
| Shortgrass Prairie | +85% | 2008 | 6 |
| Central Mixed Grass Prairie | -35% | 1994 | 10 |
| Edwards Plateau | +247% | 1984 | 17 |
| Oaks and Prairies | -54% | 1986 | 35 |
| Chihuahuan Desert | +70% | 1984 | 20 |
| Tamaulipan Brushlands | +2% | 1982 | 25 |
| Gulf Coastal Prairie | +43% | 1996 | 30 |
Cave Swallow Conservation Status
Our route-weighted index shows it up about 550% since 1980. 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.