Species · BCR 4 · BBS 2025 Release · 1966–2024
Northern Harrier In BCR 4
Northern Harrier in BCR 4 has fallen sharply: down 66% on the route-weighted index since 1987.
-66%Since 1987
30Routes In Region
34Years
Notable Signals
long arc declinecomputed index
Northern Harrier has fallen sharply in BCR 4: down 66% on the route-weighted index since 1987.
Forecast
If the recent trend holds, Northern Harrier in BCR 4 is projected to fall about 42% by 2029 — from 0.08 in 2024 to a central estimate of 0.05 (95% range 0.00–0.18). A 5-year backtest shows a typical error of ±88.8%, with 100% of held-out values landing inside the 95% band.
-42%Change by 2029
0.05Projected 2029 index
0.00–0.1895% range
±88.8%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.06 | 0.00 | 0.19 |
| 2026 | 0.06 | 0.00 | 0.19 |
| 2027 | 0.05 | 0.00 | 0.18 |
| 2028 | 0.05 | 0.00 | 0.18 |
| 2029 | 0.05 | 0.00 | 0.18 |
Routes In BCR 4
| Chistochina | ALASKA | 2 | 2023 |
| Cantwell | ALASKA | 2 | 1998 |
| Lake Louise | ALASKA | 2 | 2008 |
| Eagle | ALASKA | 1 | 2014 |
| Chatanika R | ALASKA | 1 | 2007 |
| Livengood | ALASKA | 1 | 2011 |
| Slana | ALASKA | 1 | 2024 |
| Maclaren | ALASKA | 1 | 2011 |
| Monahan | ALASKA | 1 | 2021 |
| Toklat | ALASKA | 1 | 2019 |
| Kalifonsky | ALASKA | 1 | 2016 |
| Kenny Lake | ALASKA | 1 | 2000 |
| Sourdough | ALASKA | 1 | 2013 |
| Savage | ALASKA | 1 | 2024 |
| Seven Lakes | ALASKA | 1 | 1999 |
| Burma Road | ALASKA | 1 | 1998 |
| Caribou Mtn. | ALASKA | 1 | 2023 |
| Coldfoot | ALASKA | 1 | 2011 |
| Donelly Dome | ALASKA | 1 | 2024 |
| Unalakleet River | ALASKA | 1 | 1997 |
| Hather Creek | ALASKA | 1 | 2016 |
| Manley Ht Sp | ALASKA | 1 | 2009 |
| Moose Creek | ALASKA | 1 | 1997 |
| Mt. Fairplay | ALASKA | 1 | 1996 |
| Murphy Dome | ALASKA | 1 | 2008 |
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.