Aleutian Tern
Aleutian Tern has collapsed: down 81% on the route-weighted index since 1985.
About the Aleutian Tern
The Aleutian Tern (Onychoprion aleuticus) 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 14 Breeding Bird Survey routes across 1 state, most concentrated in the BCR 2.
- Family
- Laridae · Wetland birds
Notable Aleutian Tern Trends
No notable trend signals for Aleutian Tern. See the full index history below.
Aleutian Tern Population Forecast
If the recent trend holds, Aleutian Tern is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.04). A 5-year backtest shows a typical error of ±58.5%, with 100% of held-out values landing inside the 95% band.
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.00 | 0.00 | 0.04 |
| 2026 | 0.00 | 0.00 | 0.04 |
| 2027 | 0.00 | 0.00 | 0.04 |
| 2028 | 0.00 | 0.00 | 0.04 |
| 2029 | 0.00 | 0.00 | 0.04 |
Where the Aleutian Tern Is Detected
BBS routes recording Aleutian Tern, sized by most recent count.
Aleutian Tern Population Trend by State
| Alaska | -91% | 1985 | 14 |
Aleutian Tern Population Trend by Region
Bird Conservation Regions are the ecological unit for trends.
| BCR 2 | -73% | 1985 | 10 |
Aleutian Tern Conservation Status
Our route-weighted index shows it down about 81% since 1985.
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22. Trend is a route-weighted relative-abundance index, not an absolute population.