Species · BCR 4 · BBS 2025 Release · 1966–2024
Harlequin Duck In BCR 4
Harlequin Duck in BCR 4 has increased: up 49% on the route-weighted index since 1986.
+49%Since 1986
10Routes In Region
31Years
Notable Signals
No notable trend signals for Harlequin Duck in BCR 4. See the full index history below.
Forecast
If the recent trend holds, Harlequin Duck in BCR 4 is projected to rise about 98% by 2028 — from 0.16 in 2023 to a central estimate of 0.31 (95% range 0.00–0.78). A 5-year backtest shows a typical error of ±485.4%, with 100% of held-out values landing inside the 95% band.
+98%Change by 2028
0.31Projected 2028 index
0.00–0.7895% range
±485.4%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2024 | 0.31 | 0.00 | 0.77 |
| 2025 | 0.31 | 0.00 | 0.77 |
| 2026 | 0.31 | 0.00 | 0.77 |
| 2027 | 0.31 | 0.00 | 0.77 |
| 2028 | 0.31 | 0.00 | 0.78 |
Routes In BCR 4
| Sourdough | ALASKA | 14 | 1994 |
| Unalakleet River | ALASKA | 6 | 2023 |
| Savage | ALASKA | 2 | 2007 |
| Monahan | ALASKA | 1 | 1986 |
| Cantwell | ALASKA | 1 | 2018 |
| Homer | ALASKA | 1 | 1982 |
| Hatcher Pass | ALASKA | 1 | 2007 |
| Kanuti Canyn | ALASKA | 1 | 2014 |
| Anvik River | ALASKA | 1 | 2012 |
| Tatalina | ALASKA | 1 | 2009 |
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.