A dull brown thrush with a gray belly and white eyebrows. Head pattern similar to that of Eyebrowed Thrush, but Gray-sided has no orange tones anywhere on the body. Breeds in mid- to high-altitude deciduous forests; many actually move higher in the winter, into evergreen forests, unlike most other high-altitude breeders. Forages quietly on the ground, usually solitarily. Song not as rich and melodious as other thrushes; instead gives a prolonged series of distinct short phrases consisting of bouncy, “fuzzy”-sounding notes.