Length: 24 inches | Wingspan: 55 inches | Seasonality: Rare Winter Visitor |
ID Keys: Light mantle, dark eyes, limited dark in wing-tips, shorter thinner bill than similar species, pink legs |
The Thayer's Gull was once considered a slightly smaller sub-species of the Herring Gull, and is very similar. Its status has been in flux for a number of years, with some still considering a race of Herring Gull, and others calling it and the Iceland Gull different races of the same species. Thayer's Gulls are typically darker on the wingtips than Iceland Gulls, while Iceland Gulls may have very little darker feathering in the wingtips. The "Kumlien's Gull" is considered to be a hybrid of Thayer's and Iceland Gulls, and some consider them all one species, ranging from the darker Thayer's in the west to the lighter Iceland in the east. Thayer's Gulls also readily interbreed with multiple other species on the West Coast, including Glaucous-winged and Western Gulls, making identification of Thayer's Gulls and hybrid gulls even more difficult. (NOTE: In 2017, the American Ornithological Union officially eliminated Thayer's Gull as a distinct species, instead declaring them to be a sub-species of the Iceland Gull).
Click on the map below for a higher-resolution view |
South Dakota Status: Rare migrant and winter visitor, with the vast majority of sightings along the Missouri River and its impoundments. |