Northern mockingbirds are medium-sized birds. They have long tails, and short, rounded wings. Males are larger than females. Males are 22 to 25.5 cm long and weigh about 51 g. Females are 20.8 to 23.5 cm long and weigh about 47 g. Northern mockingbirds are gray-brown on top and light gray underneath. They have a large white patch on each wing and white outer tail feathers that are easy to spot when they fly. Their bills are black and curved a little bit downward. Young northern mockingbirds look similar to adults, but they have brown spots on their underparts. (Derrickson and Breitwisch, 1992; Rylander, 2002)
Northern mockingbirds live throughout North America, including Canada and Mexico. They are most common in the southern United States, especially in Texas and Florida. They breed from northern California, eastern Nebraska, southern Ontario and Atlantic Canada to southern Mexico. (Rylander, 2002; Texas Parks & Wildlife Department, 2003; Wild Birds Forever, Date Unknown)
Northern mockingbirds like open habitats and forest edges. They are often seen in residential areas, farmlands, along roads, in city parks, open grassy areas with thickets and brushy deserts. They like grassy areas, but need a tree or other high structure to perch on. Northern mockingbirds occupy similar habitat all year. (Nature of New England, 2003; Rylander, 2002; Texas Parks & Wildlife Department, 2003)
Northern mockingbirds are usually monogamous. However, occasionally one male will mate with more than two females. Male and female breeding pairs usually stay together for a whole breeding season, and sometimes for many years.
Males choose a territory and then try to attract a female to mate there. There are three courtship displays that males use to attract female. The male may chase the female through the territory while singing, or her may run around on branches, showing the female where a nest could be built. Males also perform a “flight display”. In the “flight display”, males sing while flying a few meters into the air and then falling slowly back down. This display shows off their white wing patches to the female. (Derrickson and Breitwisch, 1992; Holoweb, 2001; Rylander, 2002)
Northern mockingbirds breed in spring and early summer. Their nests are cup-shaped and are made of twigs, cotton, dry leaves, stems, paper, grass and other organic material. The nests are built in shrubs and trees up to 50 feet above the ground.
The female lays two to six eggs (average 4 eggs). The eggs are about 24 mm long and 18 mm wide. They are blue or greenish with brown or reddish spots. Female mockingbirds incubate the eggs, males do not. The eggs hatch after 11 to 14 days. The chicks are helpless when they hatch. However, they grow quickly and can leave the nest after 10 to 12 days. When the chicks leave the nest, the male continues to feed them and teaches them to fly. The female begins building a new nest for the next brood of eggs. The fledglings become independent from their parents when they are 10 to 15 days old. They may begin breeding when they are one year old. Northern mockingbirds can raise 2 to 4 broods each year. (Derrickson and Breitwisch, 1992; Holoweb, 2001; Rylander, 2002)
Females incubate the eggs, males do not. When the eggs hatch, the female and male both feed and protect the helpless chicks. After the chicks leave the nest, the female begins to build a new nest for a second brood. During this time, the male teaches the chicks to fly and feeds them. (Derrickson and Breitwisch, 1992; Gough, et al., 1998; Sprott and Mazzotti, 2001)
Northern mockingbirds are excellent singers. They can perform at least 39 different songs and 50 different call notes. Northern mockingbirds can also imitate sounds that they hear. For example, the may imitate dogs barking or the songs of other birds.
Northern mockingbirds are solitary and territorial. During the nesting season, they are very aggressive. They attack animals that come into their territory, even big animals like cats, dogs and humans
Northern mockingbirds are diurnal. This means that they are active during the day. Some northern mockingbirds are migratory. Most mockingbirds that breed in the north fly south for the winter. Those that nest in the southern part of the range stay in the same area year-round. (Derrickson and Breitwisch, 1992; Texas Parks & Wildlife Department, 2003)
We do not have information on home range for this species at this time.
Northern mockingbirds communicate mostly using songs. They can sing at least 39 different songs and 50 other call notes. They can also imitate certain sounds such as dogs barking, pianos, sirens and squeaky gates. Songs are important in mating. Males sing to attract females and to defend their territory against other males. They sing often, at night and during the day.
Northern mockingbirds also use visual displays to communicate. For example, males perform a “flight display”. During this display, males sing and fly up and down to attract a female. (Derrickson and Breitwisch, 1992; Rylander, 2002; Sprott and Mazzotti, 2001)
Northern mockingbirds are omnivores. Their main foods are insects, berries and seeds. Insects they eat include beetles (order Coleoptera), ants (order Hymenoptera), grasshoppers (order Orthoptera) and spiders (order Araneae). They eat the fruits of holly, mulberries, raspberries, dogwoods, brambles, grapes and figs. They also eat earthworms, and sometimes small crustaceans and small lizards.
Northern mockingbirds usually search for food on the ground or while perched in a tree or shrub. They drink water from puddles, the edges of rivers or lakes, or from wet plants. (Derrickson and Breitwisch, 1992; Gough, et al., 1998; Holoweb, 2001; Rylander, 2002; Wild Birds Forever, Date Unknown)
When predators come near to a nest, adults make alarm calls. Several adults may also mob predator that enter their territory. They swoop at the predator and sometimes even hit them. (Derrickson and Breitwisch, 1992)
Northern mockingbirds play an important role as seed dispersers. After eating berries, northern mockingbirds release seeds in their feces. This helps the plant to spread its seeds. Northern mockingbirds also impact populations of the insects they eat.
Northern mockingbirds host several ectoparasites. These parasites include blowfly larvae (family Calliphoridae), fleas and mites. Finally, three cowbird species are brood parasites of northern mockingbirds. This means that the cowbirds lay eggs in the northern mockingbirds’ nests. Sometimes the northern mockingbirds will incubate the egg and raise the cowbird chicks along with their own chicks. (Derrickson and Breitwisch, 1992; Sprott and Mazzotti, 2001)
Some people may be kept awake at night by the night-time singing of northern mockingbirds. Gardeners and farmers may also loose some of their fruit and vegetable crops to these birds. (Texas Parks & Wildlife Department, 2003)
Northern mockingbirds eat insects that are pests to humans. These insects include beetles, ants, wasps and grasshoppers. Mockingbirds also disperse the seeds of many plants. Humans study the interesting behaviors and the many songs of northern mockingbirds. (Sprott and Mazzotti, 2001; Texas Parks & Wildlife Department, 2003)
Scientists are not worried about this species. Northern mockingbird populations are large. There are about 45,000,000 northern mockingbirds in the world. This species is protected by the US Migratory Bird Treaty Act. (Karl, 2000)
Alaine Camfield (editor), Animal Diversity Web.
Kari Kirschbaum (editor), Animal Diversity Web.
Eve Breitmeyer (author), University of Michigan-Ann Arbor, Phil Myers (editor), Museum of Zoology, University of Michigan-Ann Arbor.
International Birding Information Resource Data. 2000. ""Northern Mockingbird"" (On-line). i-bird.com. Accessed March 20, 2003 at http://www.i-bird.com/.
Derrickson, K., R. Breitwisch. 1992. Northern mockingbird (Mimus polyglottos). Pp. 1-24 in A Poole, P Stettenheim, F Gill, eds. The Birds of North America, Vol. 7. Philadelphia, PA: The Academy of Natural Sciences and Washington DC: The American Ornithologists Union.
Enature.com, 2003. "Birds: Northern Mockingbird" (On-line). Enature.com. Accessed April 15, 2004 at http://www.enature.com/fieldguide/showSpeciesGS.asp?sort=1&curGroupID=99&display=1&area=99&searchText=northern+mockingbird&curPageNum=1&recnum=BD0136.
Gough, G., J. Sauer, M. Iliff. 1998. "Patuxent Bird Identification Infocenter" (On-line). Accessed April 15, 2004 at http://www.mbr-pwrc.usgs.gov/Infocenter/infocenter.html.
Holoweb, 2001. ""Northern Mockingbird: Mimus polyglottos" (On-line). Animals Identified on the Property or Known to Live in South East Minnesota. Accessed April 15, 2004 at http://www.holoweb.com/cannon/northergn.htm.
Karl, J. 2000. "Mimus polyglottos (Northern mockingbird)" (On-line). Accessed April 15, 2004 at http://imnh.isu.edu/digitalatlas/bio/birds/sngbrd/thrashr/nomo/nomo_mai.htm.
Nature of New England, 2003. ""Northern Mockingbird"" (On-line). Nature of New England. Accessed April 15, 2004 at http://www.nenature.com/NorthernMockingbird.htm.
Rylander, K. 2002. ""Northern Mockingbird"" (On-line). The Handbook of Texas Online. Accessed April 15, 2004 at http://www.tsha.utexas.edu/handbook/online/articles/view/NN/tbn1.html.
Sprott, P., F. Mazzotti. 2001. "Mockingbirds (mimus polyglottos)" (On-line). Edis. Accessed April 15, 2004 at http://edis.ifas.ufl.edu/BODY_UW094.
Texas Parks & Wildlife Department, 2003. "Nature: Northern Mockingbird" (On-line). Texas Parks and Wildlife. Accessed April 15, 2004 at http://www.tpwd.state.tx.us/factsheets/birds/mockingbird/mockingbird.htm.
Wild Birds Forever, Date Unknown. "Attracting the Northern Mockingbird" (On-line). Wild Birds Forever. Accessed April 15, 2004 at http://www.birdsforever.com/mock.html.