The northern mockingbird is robin-sized but is more slender than a robin. It is gray above and gray-white below and has conspicuous white wing patches and white outer tail feathers. The sexes appear almost identical and are rarely separable in the field, but the female is on the average smaller and has slightly darker outer tail feathers. The western subspecies has a relatively shorter tail and is somewhat more buff-colored below. Partial and total albinism have been reported.
Northern mockingbirds occur throughout the United States except in the most northern regions.
Their range extends south into Mexico and the West Indies. In Texas the species is a permanent resident from sea level to over 6,000 feet above sea level, and it is particularly common in gardens, parks, brushy areas, and along roadsides. It is rarely seen in deep forests or on prairies devoid of shrubs or small trees. It feeds on insects and other small animals, including lizards, snails, and sowbugs, as well as on fruits and berries. A unique behavior in mockingbirds is called wing-flashing.