Great Black-backed Gull
Great Black-backed Gull has held roughly steady: down 5% on the route-weighted index since 1968.
About the Great Black-backed Gull
The Great Black-backed Gull (Larus marinus) is a North American member of the Gulls, Terns & Skimmers (Laridae). In this analysis it is grouped with the wetland birds.
- Size
- 8.5–31.5 in long (22–80 cm) — a long-winged waterbird (typical for the family)
- Habitat
- Marshes, ponds, lakeshores and other freshwater wetlands.
- Diet
- Aquatic invertebrates, small fish, frogs and plant matter.
- Range
- Recorded on 82 Breeding Bird Survey routes across 13 states, most concentrated in the New England / Mid-Atlantic Coast.
- Family
- Laridae · Wetland birds
Notable Great Black-backed Gull Trends
No notable trend signals for Great Black-backed Gull. See the full index history below.
Great Black-backed Gull Population Forecast
If the recent trend holds, Great Black-backed Gull is projected to stay roughly flat through 2029, near 0.03 (95% range 0.00–0.06). A 5-year backtest shows a typical error of ±239.8%, with 100% of held-out values landing inside the 95% band.
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.03 | 0.00 | 0.06 |
| 2026 | 0.03 | 0.00 | 0.06 |
| 2027 | 0.03 | 0.00 | 0.06 |
| 2028 | 0.03 | 0.00 | 0.06 |
| 2029 | 0.03 | 0.00 | 0.06 |
Where the Great Black-backed Gull Is Detected
BBS routes recording Great Black-backed Gull, sized by most recent count.
Great Black-backed Gull Population Trend by State
| Connecticut | +7% | 1976 | 3 |
| Delaware | -67% | 1968 | 8 |
| Maine | +111% | 1968 | 17 |
| Maryland | +6% | 1975 | 11 |
| Massachusetts | -62% | 1970 | 12 |
| New Hampshire | -81% | 1969 | 5 |
| New Jersey | +580% | 1984 | 5 |
| New York | +203% | 1972 | 7 |
| North Carolina | -88% | 1982 | 5 |
| Ohio | insufficient data | n/a | 1 |
| Rhode Island | +324% | 1971 | 3 |
| Vermont | insufficient data | n/a | 1 |
| Virginia | -11% | 1996 | 4 |
Great Black-backed Gull Population Trend by Region
Bird Conservation Regions are the ecological unit for trends.
| Atlantic Northern Forest | -59% | 1971 | 16 |
| Southeastern Coastal Plain | -75% | 1982 | 5 |
| New England / Mid-Atlantic Coast | +137% | 1968 | 55 |
Great Black-backed Gull Conservation Status
Our route-weighted index shows it down about 5% since 1968.
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22. Trend is a route-weighted relative-abundance index, not an absolute population.