Small and compact with a small bill and a shorter tail compared to larger sparrows. Males have a gray head, a vivid rusty shoulder patch, a black throat, and a yellow patch at the base of the white mustache. Females are relatively clean-looking compared to males. Song is a series of high-pitched, sharp “tzip-tzip-tzip…” notes. The flight call is higher-pitched than larger sparrows. Breeds in thick scrub and trees where it builds a large and prominent nest that has unique thermoregulating properties for hot climates. A partial and short-distance migrant; moves in tight, fast-moving flocks.