Species · BCR 14 · BBS 2025 Release · 1966–2024
Great Black-backed Gull In Atlantic Northern Forest
Great Black-backed Gull in Atlantic Northern Forest has fallen sharply: down 59% on the route-weighted index since 1971.
-59%Since 1971
16Routes In Region
35Years
Notable Signals
long arc declinecomputed index
Great Black-backed Gull has fallen sharply in Atlantic Northern Forest: down 59% on the route-weighted index since 1971.
Forecast
If the recent trend holds, Great Black-backed Gull in Atlantic Northern Forest is projected to fall about 100% by 2012 — from 0.06 in 2007 to a central estimate of 0.00 (95% range 0.00–0.11). A 5-year backtest shows a typical error of ±78.6%, with 100% of held-out values landing inside the 95% band.
-100%Change by 2012
0.00Projected 2012 index
0.00–0.1195% range
±78.6%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2008 | 0.01 | 0.00 | 0.11 |
| 2009 | 0.00 | 0.00 | 0.11 |
| 2010 | 0.00 | 0.00 | 0.11 |
| 2011 | 0.00 | 0.00 | 0.11 |
| 2012 | 0.00 | 0.00 | 0.11 |
Routes In Atlantic Northern Forest
| Hartford | MAINE | 7 | 1988 |
| Newcastle | MAINE | 4 | 2007 |
| Medway | MAINE | 3 | 1979 |
| Biddeford | MAINE | 2 | 1975 |
| Deblois | MAINE | 2 | 1998 |
| Westbrook | MAINE | 1 | 1988 |
| Turner | MAINE | 1 | 1996 |
| Warren | MAINE | 1 | 1985 |
| Brooks | MAINE | 1 | 1993 |
| Hancock | MAINE | 1 | 1987 |
| Castine | MAINE | 1 | 2000 |
| Cooper | MAINE | 1 | 2007 |
| Moose River | MAINE | 1 | 1987 |
| St David | MAINE | 1 | 2005 |
| Jefferson | MAINE | 1 | 1996 |
| Jefferson Hl | NEW-HAMPSHIRE | 1 | 1993 |
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.