Northern Rough-winged Swallow
Northern Rough-winged Swallow has risen sharply: up 64% on the route-weighted index since 1968.
About the Northern Rough-winged Swallow
The Northern Rough-winged Swallow (Stelgidopteryx serripennis) 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 3,354 Breeding Bird Survey routes across 49 states, most concentrated in the Appalachian Mountains.
- Family
- Hirundinidae · Aerial insectivores
Notable Northern Rough-winged Swallow Trends
Northern Rough-winged Swallow has risen sharply in surveyed states: up 64% on the route-weighted index since 1968.
Northern Rough-winged Swallow Population Forecast
If the recent trend holds, Northern Rough-winged Swallow is projected to rise about 16% by 2029 — from 1.5 in 2024 to a central estimate of 1.7 (95% range 0.89–2.5). A 5-year backtest shows a typical error of ±33%, with 100% of held-out values landing inside the 95% band.
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 1.7 | 0.88 | 2.5 |
| 2026 | 1.7 | 0.88 | 2.5 |
| 2027 | 1.7 | 0.89 | 2.5 |
| 2028 | 1.7 | 0.89 | 2.5 |
| 2029 | 1.7 | 0.89 | 2.5 |
Where the Northern Rough-winged Swallow Is Detected
BBS routes recording Northern Rough-winged Swallow, sized by most recent count.
Northern Rough-winged Swallow Population Trend by State
| Alabama | +39% | 1968 | 108 |
| Alaska | insufficient data | n/a | 2 |
| Arizona | -56% | 1970 | 58 |
| Arkansas | +436% | 1969 | 50 |
| California | -54% | 1970 | 203 |
| Colorado | -43% | 1970 | 117 |
| Connecticut | +295% | 1969 | 18 |
| Delaware | -60% | 1968 | 13 |
| Florida | -34% | 1969 | 75 |
| Georgia | +45% | 1968 | 96 |
| Idaho | -16% | 1970 | 55 |
| Illinois | +458% | 1968 | 104 |
| Indiana | +53% | 1968 | 64 |
| Iowa | +2% | 1969 | 38 |
| Kansas | +63% | 1969 | 64 |
| Kentucky | -22% | 1968 | 64 |
| Louisiana | +220% | 1969 | 65 |
| Maine | -92% | 1972 | 27 |
| Maryland | +88% | 1968 | 67 |
| Massachusetts | +24% | 1970 | 29 |
| Michigan | +19% | 1968 | 87 |
| Minnesota | -51% | 1969 | 66 |
| Mississippi | 39× | 1969 | 67 |
| Missouri | +290% | 1969 | 85 |
| Montana | +25% | 1970 | 85 |
| Nebraska | +270% | 1969 | 63 |
| Nevada | +225% | 1970 | 36 |
| New Hampshire | -76% | 1968 | 21 |
| New Jersey | +52% | 1969 | 27 |
| New Mexico | -18% | 1970 | 52 |
| New York | -11% | 1968 | 104 |
| North Carolina | +53% | 1968 | 99 |
| North Dakota | +109% | 1969 | 46 |
| Ohio | +42% | 1968 | 89 |
| Oklahoma | +162% | 1969 | 67 |
| Oregon | +29% | 1970 | 100 |
| Pennsylvania | +84% | 1968 | 122 |
| Rhode Island | -17% | 1987 | 4 |
| South Carolina | +239% | 1968 | 42 |
| South Dakota | +219% | 1969 | 50 |
| Tennessee | +219% | 1968 | 51 |
| Texas | +84% | 1969 | 155 |
| Utah | -7% | 1970 | 79 |
| Vermont | +34% | 1969 | 24 |
| Virginia | -15% | 1968 | 66 |
| Washington | -9% | 1970 | 103 |
| West Virginia | -5% | 1968 | 58 |
| Wisconsin | -17% | 1968 | 91 |
| Wyoming | -12% | 1970 | 98 |
Northern Rough-winged Swallow Population Trend by Region
Bird Conservation Regions are the ecological unit for trends.
Northern Rough-winged Swallow Conservation Status
Our route-weighted index shows it up about 64% 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.