Small warbler with a small bill and a large-headed appearance. Similar to other leaf warblers, but Brooks’s Leaf Warbler has the combination of a dark bill with a pale base, yellow on face and breast, yellow crown stripe, and at least one white wingbar (often two). Forages in a restless manner in the mid-canopy of spruce and fir forests in the summer and dry scrub forests in the winter. The distinctive song consists of high-pitched “zip-zip-zip-...” notes followed by a dry trill. The call is a short “chee-up” similar to that of a Greenish Warbler.