The state bird of Tennessee is the northern mockingbird, which was chosen as Tennessee's official state bird in 1933. Scientifically known as Mimus polyglottos, these birds are perhaps best known for their incredible vocal versatility. Their songs often imitate the songs of other birds, and a single mockingbird song may incorporate elements of several other species' songs simultaneously They have even been known to imitate mechanical noises. The state bird of Tennessee is generally gray, with a more whitish breast, and distinctive white stripes on its black wings. Once rare in the wild due to its former popularity as a cage bird, the northern mockingbird is now considered common, and can usually be found in open grasslands and cultivated areas.
The northern mockingbird generally reaches lengths of between 8.3 to 10.2 inches (21 to 26 centimeters). It usually weighs between 1.6 and 2 ounces (45 to 58 grams). It typically builds a cup-like nest out of twigs, leaves and grasses, but has been known to incorporate cigarette filters, shreds of thin plastic, and other refuse in its nests.
Both males and females of the species contribute to nest construction. Males generally build most of the nest, as nest building typically forms part of the northern mockingbird's mating display. Males may build a number of nests, usually in trees or bushes 3 to 10 feet (0.9 to 3.05 meters) above the ground. The female will normally choose one of these nests, finish it off by lining it with softer nesting materials, and then lay up to five mottled brown eggs in it. The male of this species typically takes on a primary role in caring for the fledglings, and the female northern mockingbird may, in fact, lay more eggs in a second nest while the male cares for the first brood.
These birds typically sing more often at certain times of the year, and the males normally sing far more often than the females. Northern mockingbirds generally sing the most from February to August, and from September to November. The state bird of Tennessee is known for singing throughout the day and night. Males who have not found mates generally sing more often than do mated males or females. Female northern mockingbirds usually sing more in the autumn. They may sing during the summer months, if their mate is absent.
The northern mockingbird is now considered common in the wild, and can be found across much of North America, Mexico, and even some parts of the Caribbean. In the 19th century, however, the state bird of Tennessee was considered so popular as a cage bird that it nearly disappeared from the wild. These birds were considered desirable for their vast song repertoires.