Northern Mockingbird, Mimus polyglottos
The Northern Mockingbird is the Tennessee state bird. The scientific name is appropriately Mimus polyglottos, translated as "many-tongued mimic." The name highlights the mockingbird's ability to mimic not only dozens of other birds' songs, but also man-made devices such as musical instruments, warning bells, cell phones, car horns, and creaky hinges.
The mockingbird is known to many homeowners by its (some would describe obnoxious) habitat of singing on moonlit spring nights. These songsters usually unmated males, but in well-lit areas, even mated males may sing at night.
The Northern Mockingbird is very territorial and will dive and attack intruders, including homeowners and their pets, and may even attack its own reflection in a window!
The Northern Mockingbird is a year round resident across most of the continental United States to southern Mexico and the Caribbean. Although populations have recently declined in the southern part of its range, mockingbirds have expanded northward during the past century, especially in suburbs with berry producing ornamental shrubs.
Description: This medium-sized songbird is gray above and white below. The darker wings have 2 white wingbars, and the white patches in the wings are conspicuous in flight. The tail is long with white outer tail feathers and is often held in a cocked position. Males and females look alike.
Weight: 1.7 oz
Voice: Each individual mockingbird has a unique mix of original and imitated phrases that are repeated three or more times. The call note is an abrasive check. Both male and female sing in fall to claim feeding territories.
- Loggerhead Shrikes have black wings with less white, a black mask, and fly with wingbeats too fast to count.
- Gray Catbirds are darker gray all over, without white in the wings and tail.
- Blue-gray Gnatcatchers are similar in color, but are significantly smaller, lack much white in wing, and have a white eye-ring.
Habitat: Northern Mockingbirds are found in areas with open ground and shrubby vegetation such as in parkland, cultivated land, and suburbs. They are especially fond of invasive multiflora rose thickets.
Diet: Ants, beetles, grasshoppers, seeds and berries.
Nesting and reproduction: Some adults may spend the entire year as a pair on a single territory, while others establish distinct breeding and wintering territories. In Tennessee the breeding season extends from late March into August with pairs producing as many as 4 broods in one season.
Clutch Size: Normally 3 to 5 eggs.
Incubation: Females alone incubate the eggs for 12 to 13 days.
Fledging: Both adults feed the young, which fledge in about 12 days.
Nest: The male and female build the open cup-nest of dead twigs lined with grasses, rootlets, and dead leaves. It is placed low in dense shrubs, deciduous trees, and small evergreens. Nest heights in Tennessee have been reported from ground level to 52 feet high, but most are below 7 feet.
Status in Tennessee: The Northern Mockingbird is still a common permanent resident across the state though it has been declining for several decades. The reasons for the decline are not known, but the maturing forests and a trend toward "cleaner" farms with fewer fencerows in the state may be a contributing factor.
- The Northern Mockingbird was named the official state bird of Tennessee in 1933.
- Nestling mockingbirds banded in Nashville have been recaptured 200 miles away!
- Like the Gray Catbird, mockingbirds are able to differentiate Brown-headed Cowbirds eggs from their own. Mockingbirds will eject cowbird eggs from the nest, preventing decreased nesting success caused by this nest parasite.
- A male's song repertoire may contain as many as 200 distinct song types. These songs may change during his adult life and increase in number with age. Songs are acquired through imitating the calls and songs of other birds, the vocalizations of non-avian species, mechanical sounds, and the sounds of other mockingbirds.
- The Northern Mockingbird typically sings throughout most of the year: from February through August and again from September through early November. A male may have two distinct repertoires of songs: one for spring and another for fall. One study found only a one percent overlap in song types used in spring and fall.
- The female Northern Mockingbird sings too, although usually more quietly than the male. She rarely sings in the summer, usually only when the male is away from the territory. She sings more in the fall perhaps to establish a winter territory.
- The Northern Mockingbird frequently gives a "wing flash" display, where it opens its wings in a jerky fashion. It has been suggested that they do this to startle insects and make them easier to catch.
- The oldest known Northern Mockingbird in the wild was 14 years 10 months old.
Obsolete English Names: mockingbird
Best places to see in Tennessee: Most easily seen in suburban areas across the state, anywhere with dense berry-producing shrubs.
Derrickson, K. C. and R. Breitwisch. 1992. Northern Mockingbird (Mimus polyglottos), The Birds of North America (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists' Union, Washington, D.C.
Nicholson, C. P. 1997. Atlas of Breeding Birds of Tennessee. Univ. Tennessee Press, Knoxville.
Sibley, D. A. 2000. The Sibley Guide to Birds. A. A. Knopf, New York, NY.