Northern Mockingbird (Mimus polyglottos)

northern mockingbird

Northern Mockingbirds, Mimus polyglottos, are small songbirds in the Mimidae family that can be found on every continent except Antarctica. They are most commonly found in North America, but live as far south as Central America and as far north as Canada, and have also been spotted in Europe and Asia.

Northern Mockingbirds are known to mimic other bird songs; however, they can also mimic other animal sounds, sirens, and mechanical noises such as doorbells and car alarms.

Their populations have undergone drastic declines in the past century due to habitat loss and fragmentation as well as nest site competition with European Starlings (Sturnus vulgaris).

These threats coupled with small breeding population sizes make Mimus polyglottos an endangered species under the United States Endangered Species Act of 1973 and an endangered species under Canada’s Species at Risk Act of 2002.

Description

male northern mockingbird
Male northern mockingbird

The Northern Mockingbird is found in Eastern North America, from southern Canada to the Gulf Coast and as far west as Texas. The Northern Mockingbird prefers open country, woodland borders, parks, and gardens. The Northern Mockingbird is one of the most abundant species of bird found in North America.

They have an easily identifiable white underbelly and spots on their feathers. During the summer months, it builds its nest close to the ground or on a horizontal branch close to the ground. It will also use man-made structures such as mailboxes or fences for nesting. In winter they roost communally with several other mockingbirds at night.

Scientific name

The scientific name of the Northern Mockingbird is Mimus polyglottos

Northern mockingbird habitat

The northern mockingbird lives in all contiguous 48 states, Alaska, and Canada. They also live in parts of Mexico, Costa Rica, and the Caribbean. Although they are not found in most of Europe or Asia, they can sometimes be found as vagrants on occasion. Their natural habitat is open land that has a mix of shrubs and trees; you will find them hunting on ground level or up to 4 meters above the ground.

Size and weight

The size of the northern mockingbirds is around 21 – 26 cm (8.3 – 10.2 inches) and weighs around 45 – 58 g (1.6 – 2.0 oz ) with a wingspan of around 31 – 35 cm (12.2 -13.8 inches).

Feathers and plumage

northern mockingbird

The feathers of a Northern Mockingbird are mostly black, with white barring and eye markings. The Northern Mockingbird’s colorful plumage actually appears to be drabber from a distance than at close range.

Feathers consist of barbs that attach to the bird’s body and barbules, which attach individual feather barbs together. Like those of other perching birds, these feathers grow as the bird grows and they develop a shaft where the feather attaches to the wing or tail.

Molting

The Northern mockingbird molts twice per year, once in the spring and again in the fall. A mockingbird can only molt while they are in a safe place and away from predators, otherwise, they are in danger of being captured before they are able to finish the process.

Unlike some other bird species, Northern mockingbirds do not show signs of weakness after their molt is complete; it simply takes about one month for their feathers to become strong and waterproof again.

Nesting behavior

Northern Mockingbirds typically nest in shrubs and trees at a height of 3-10 feet off the ground, though sometimes as high as 60 feet. It is the male who chooses the nest site and typically builds the nest first, but then it is the female who decides to finish building it and lay her eggs in it.

In late winter, the nesting process begins. The male sings to protect his territory and attract a mate, often jumping into the air and flapping his wings as he sings. Early on in their courtship, the male and females try to escape one another, running around the territory rapidly.

The nest is placed in a deep thick bush or tree, usually, 3 to 10 feet above the ground, sometimes less or more (rarely up to 60 feet). The nest is composed of a bulky structure of twigs, supporting an open cup of dry plants, and dried leaves, lined with finer materials such as silk, animal hair, or other plant material. Men generally construct the majority of the house’s foundations while women fill in the gaps with a less complex interior lining.

Diet and foraging

The northern mockingbird is omnivorous, which means that it will eat both meat and plants. They hunt insects such as caterpillars and beetles on the ground, but they also eat seeds, berries, snails, worms, and small fish.

Vocal behavior and sounds of a mockingbird

Both male and female mockingbirds sing, with them sometimes mimicking the sounds of other birds or frogs. This may include blackbirds, orioles, shrikes, killdeer, jays, and many others. Throughout their lives, they learn new sounds. It consists of endless phrases that are then repeated 1 to 6 times before switching them out. Some may go on for a long time (about 20 seconds).

Mockingbirds do not only whistle phrases, but they also make harsher sounds such as rasps, scolds, and trills. Unmated males are the noisiest, singing at all hours. Unlike Gray Catbirds, who typically sing more variable phrases, Brown Thrashers are limited in the variety of their singing and use it less often.

Its harsh, dry chew or hew is made when it mobs nest predators or chases other mockingbirds. During incubation and nestling periods, or if the female leaves the nest while incubating, mates exchange softer versions of this sound. Mockingbirds also make a series of 2-8 short, scratchy chat calls to warn off intruders. Females make a single chat call when disturbed.

Breeding

northern mockingbird

Monogamy is the most common behavior among northern mockingbirds. More than two females may be mated by a male occasionally. Breeding pairs of males and females often remain together for months or even years during the breeding season.

Females northern mockingbirds will mate with males after they claim their territories.

Females are attracted by three types of courtship displays. While singing or running around on branches, males chase females through their territories in order to show them where a nest can be built. While singing as they fall slowly back to the ground, males also perform a “flight display.”

The male shows off his white wing patches to the female in this display.

Early spring and early summer are the best times for northern mockingbirds to breed. In addition to twigs, cotton, dry leaves, stems, paper, grass, and other organic materials, they build their nests in a cup-shaped form. Trees and shrubs up to 50 feet high are used to build the nests.

It is common for the female to lay between two and six eggs (an average of four eggs). The eggs have a diameter of 18 mm and a length of 24 mm. There are brown or reddish spots on their blue or greenish bodies. Eggs are incubated by female mockingbirds. It takes 11 to 14 days for the eggs to hatch. A chick’s helplessness is apparent from the moment it hatches.

In spite of this, they grow rapidly, and they are able to leave the nest within 10 to 12 days after hatching.

Chicks are fed and taught to fly by the male even after they have left the nest. During this time, a new nest is being built by the female for the next brood of eggs. During their first 10 to 15 days of life, fledglings become independent of their parents.

After one year of age, they may start breeding. The northern mockingbird is capable of raising two to four broods per year.

Lifespan

There have been cases of northern mockingbirds living to 20 years of age in captivity, whereas in the wild, their lifespan is eight years.