butter butts n.— «Audubon warblers, the Western form of the yellow-rumped warbler, also were moving through in large numbers early last week. These blue and yellow warblers are affectionately called “butter butts” by many birders due to...
butter butts n.— «Audubon warblers, the Western form of the yellow-rumped warbler, also were moving through in large numbers early last week. These blue and yellow warblers are affectionately called “butter butts” by many birders due to...