The darker the color, the more favorable the climate conditions are for survival. The outlined areas represent approximate current range for each season. More on reading these maps.
Although common and well-known where it occurs, the Western Gull is actually one of our most range-restricted gulls. The species is basically limited to the West Coast, being quite rare just a few miles inland. Audubon's climate model projects a 72 percent loss of current winter range by 2080, with some potential expansion eastward and northward. However, being such a range-restricted species currently, scarcely seen inland even 30 miles inland, the eastward spread seems unlikely. As it spreads north, its hybridization with Glaucous-winged Gull is likely to increase still further.