Black-legged Kittiwake
Black-legged Kittiwake has surged: up 572% on the route-weighted index since 1982.
About the Black-legged Kittiwake
The Black-legged Kittiwake (Rissa tridactyla) 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 16 Breeding Bird Survey routes across 2 states, most concentrated in the Northern Pacific Rainforest.
- Family
- Laridae · Wetland birds
Notable Black-legged Kittiwake Trends
No notable trend signals for Black-legged Kittiwake. See the full index history below.
Black-legged Kittiwake Population Forecast
If the recent trend holds, Black-legged Kittiwake is projected to rise about 23% by 2029 — from 0.12 in 2024 to a central estimate of 0.15 (95% range 0.00–0.41). A 5-year backtest shows a typical error of ±483.4%, with 100% of held-out values landing inside the 95% band.
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.14 | 0.00 | 0.40 |
| 2026 | 0.14 | 0.00 | 0.40 |
| 2027 | 0.14 | 0.00 | 0.41 |
| 2028 | 0.15 | 0.00 | 0.41 |
| 2029 | 0.15 | 0.00 | 0.41 |
Where the Black-legged Kittiwake Is Detected
BBS routes recording Black-legged Kittiwake, sized by most recent count.
Black-legged Kittiwake Population Trend by State
| Alaska | +21% | 1983 | 15 |
| Washington | insufficient data | n/a | 1 |
Black-legged Kittiwake Population Trend by Region
Bird Conservation Regions are the ecological unit for trends.
| BCR 2 | 49× | 1990 | 6 |
| Northern Pacific Rainforest | -81% | 1984 | 7 |
Black-legged Kittiwake Conservation Status
Our route-weighted index shows it up about 572% since 1982.
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22. Trend is a route-weighted relative-abundance index, not an absolute population.