Greater Scaup
Greater Scaup has surged: up 234% on the route-weighted index since 1984.
About the Greater Scaup
The Greater Scaup (Aythya marila) 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 58 Breeding Bird Survey routes across 1 state, most concentrated in the BCR 4.
- Family
- Anatidae · Waterfowl
Notable Greater Scaup Trends
No notable trend signals for Greater Scaup. See the full index history below.
Greater Scaup Population Forecast
If the recent trend holds, Greater Scaup is projected to fall about 53% by 2029 — from 0.19 in 2024 to a central estimate of 0.09 (95% range 0.02–0.16). A 5-year backtest shows a typical error of ±38.2%, with 80% of held-out values landing inside the 95% band.
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.08 | 0.01 | 0.15 |
| 2026 | 0.08 | 0.01 | 0.15 |
| 2027 | 0.09 | 0.02 | 0.15 |
| 2028 | 0.09 | 0.02 | 0.15 |
| 2029 | 0.09 | 0.02 | 0.16 |
Where the Greater Scaup Is Detected
BBS routes recording Greater Scaup, sized by most recent count.
Greater Scaup Population Trend by State
| Alaska | +45% | 1984 | 58 |
Greater Scaup Population Trend by Region
Bird Conservation Regions are the ecological unit for trends.
| BCR 2 | +173% | 1986 | 19 |
| BCR 3 | -28% | 1996 | 5 |
| BCR 4 | -82% | 1985 | 27 |
| Northern Pacific Rainforest | -50% | 1984 | 6 |
Greater Scaup Conservation Status
Our route-weighted index shows it up about 234% since 1984.
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22. Trend is a route-weighted relative-abundance index, not an absolute population.