Introduction

The Northern Mockingbird, a year-round resident throughout most of its range, is renowned for its complex, ebullient, mimicking song and for its pugnacious defense of territory, nest, and young. An omnivore, this species eats a wide variety of fruit and insects, favoring habitats such as park and cultivated lands, second growth at low elevations, and suburbs, where it commonly forages for insects on mowed lawns. Although this mockingbird has recently declined in the southern part of its range, it has expanded northward during the past century, a trend likely to continue as suburbs and areas of second growth spread.

Both male and female mockingbirds sing, unmated males at night. Amale’s repertoire often contains more than 150 distinct song types which change during its adult life and may 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.

Northern Mockingbirds typically pair monogamously, but bigamous and polyandrous matings do occur. Some adults may spend the entire year as a pairon a single territory, while others establish distinct breeding and wintering territories.

During their first winter, mockingbirds either set up their own territory or move around together in flocks. The causes of these differences in social organization are unknown. Parental care is shared more or less equally by the sexes, although females perform all incubation and nearly all brooding of young nestlings. Mockingbirds overlap successive nesting attempts, and their temporal division of labor allows them to produce up to four broods each breeding season. Because they are numerous, geographically widespread, conspicuous in their activities, and complex singers, mockingbirds have proven an excellent species for behavioral studies.