19-3-2017 MIAMI, FLORIDA - NORTHERN MOCKINGBIRD (Mimus polyglottos)

The Northern mockingbird (Mimus polyglottos) is a mockingbird commonly found in North America and has rarely been observed in Europe. The bird is known for its mimicking ability, as reflected by the meaning of its scientific name, "many-tongued thrush". The Northern mockingbird is also known for its intelligence and is the state bird of five states, appears in book titles, songs, and lullabies, and makes other appearances in popular culture.

The Northern mockingbird is a medium-sized bird with long legs and a tail. Males and females look alike. Its upper parts are colored gray, while its underparts have a white or whitish-gray color. It has parallel wing bars on half of the wings connected near the white patch giving it a distinctive appearance in flight. The black central rectrices and typical white lateral rectrices are also noticeable in flight. The iris is usually a light green-yellow or yellow, but there have been instances of an orange color. The bill is black with a brownish-black appearance at the base. The juvenile appearance is marked by the streaks on its back, distinguished spots and streaks on its chest, and a gray or grayish-green iris.

Northern mockingbirds breed in southeastern Canada, the United States, northern Mexico, the Bahamas, the Cayman Islands, and the Greater Antilles. These birds are generally year-round residents of their range, but the populations that live in the northern portion of their range move further south during the winter season. Northern mockingbirds prefer forest edges and open areas with sparse vegetation. In the eastern regions, suburban and urban areas such as parks and gardens are frequent residential areas. In western regions, desert scrub and chaparral are among their preferred habitats. When foraging for food, Northern mockingbirds prefer short grass.

Northern mockingbirds are omnivores. They eat insects, earthworms, berries, fruits, seeds, and occasionally lizards. They can drink from puddles, river and lake edges, or dew and rain droplets that amass onto plants. Adult mockingbirds may also drink sap from the cuts on recently pruned trees.

Northern mockingbirds are active during the day and are usually seen singly or in pairs. They forage on the ground or in vegetation and also fly down from a perch to capture their food. While foraging, mockingbirds frequently spread their wings in a peculiar two-step motion to display the white patches. When on the ground they move by hopping, walking, and may even running. Northern mockingbirds are aggressive and territorial birds, especially around prime feeding areas. They use various threat postures to fend off intruders and may even mob and dive at humans if they venture too close to nesting areas. Northern mockingbirds generally communicate with the help of songs and various calls. Both males and females sing, with the latter being generally quieter and less vocal. Males start singing in late January to February and continue into the summer and the establishing of territory into the fall. Females sing less often in the summer and fall and only sing when the male is away from the territory. Northern mockingbirds have four main calls; these include the nest relief call, hew call, chat or chatburst, and the begging call. The hew call is mainly used by both sexes for potential nest predators, conspecific chasing, and various interactions between mates. The differences between chats and chatbursts are frequency of use, as chats are year-round, and chatbursts occur in the fall. Another difference is that chatbursts appear to be used in territorial defense in the fall, and the chats are used when mockingbirds are disturbed. The nest relief and begging calls are only used by the males.

Northern mockingbirds form monogamous pairs that remain together for many years, but incidents of polygyny (one male to several females) have also been reported. These birds breed in the spring and early summer and produce 2-4 broods a year. The males arrive before the beginning of the season to establish their territories. They use a series of courtship displays to attract females to their sites. The males run around the area either to showcase their territory to the females or to pursue the females. The males also engage in a flight to showcase their wings. They sing and call as they perform all of these displays. Both the male and female are involved in the nest building. The male does most of the work, while the female perches on the shrub or tree where the nest is being built to watch for predators. The outer part of the nest is composed of twigs, while the inner part is lined with grasses, dead leaves, moss, or artificial fibers. The female lays 3 to 5 light blue or greenish speckled with dots eggs and incubates them for nearly 2 weeks. The chicks are altricial, meaning that, when hatched, they are born relatively immobile and defenseless and therefore require nourishment for a certain duration from their parents. After about 10 to 15 days of life, the chicks become independent and reach reproductive maturity after one year of life.