Harlequin Duck
Harlequin Duck has surged: up 239% on the route-weighted index since 1982.
About the Harlequin Duck
The Harlequin Duck (Histrionicus histrionicus) is a North American member of the Ducks, Geese & Waterfowl (Anatidae). In this analysis it is grouped with the waterfowl.
- Size
- 12–43.5 in long (30–110 cm) — a medium to large waterfowl (typical for the family)
- Habitat
- Lakes, ponds, rivers, marshes and sheltered coastal waters.
- Diet
- Aquatic plants, seeds and invertebrates, dabbled at the surface or dived for.
- Range
- Recorded on 51 Breeding Bird Survey routes across 7 states, most concentrated in the Northern Pacific Rainforest.
- Family
- Anatidae · Waterfowl
Notable Harlequin Duck Trends
No notable trend signals for Harlequin Duck. See the full index history below.
Harlequin Duck Population Forecast
If the recent trend holds, Harlequin Duck is projected to stay roughly flat through 2029, near 0.01 (95% range 0.00–0.05). A 5-year backtest shows a typical error of ±58.4%, with 100% of held-out values landing inside the 95% band.
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.01 | 0.00 | 0.05 |
| 2026 | 0.01 | 0.00 | 0.05 |
| 2027 | 0.01 | 0.00 | 0.05 |
| 2028 | 0.01 | 0.00 | 0.05 |
| 2029 | 0.01 | 0.00 | 0.05 |
Where the Harlequin Duck Is Detected
BBS routes recording Harlequin Duck, sized by most recent count.
Harlequin Duck Population Trend by State
| Alaska | -76% | 1983 | 38 |
| California | insufficient data | n/a | 1 |
| Idaho | insufficient data | n/a | 2 |
| Montana | insufficient data | n/a | 1 |
| Oregon | insufficient data | n/a | 1 |
| Washington | -73% | 2000 | 5 |
| Wyoming | insufficient data | n/a | 3 |
Harlequin Duck Population Trend by Region
Bird Conservation Regions are the ecological unit for trends.
| BCR 2 | -73% | 1987 | 12 |
| BCR 4 | +49% | 1986 | 10 |
| Northern Pacific Rainforest | +63% | 1984 | 18 |
| Northern Rockies | -38% | 1993 | 6 |
Harlequin Duck Conservation Status
Our route-weighted index shows it up about 239% 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.