Courtesy Kenn Kaufman
Boat-tailed Grackles are permanent residents along the Gulf and Atlantic coasts of the United States, from mid-Texas to Virginia. Breeding populations reach Long Island, New York. These grackles also occur across the Florida peninsula.
A legend for the range map to the right can be found here
The Boat-tailed Grackle is always close to tidal water, but nests on freshwater marshes, lakes, and impoundments. Groves and tall vegetation are used for breeding and roosting. Like other grackles, this species forages over a variety of habitats: salt or freshwater marshes, mudflats, beaches, farmlands, parks, and open, urban areas.
The omnivorous Boat-tailed Grackle’s diet changes with the seasons. Walking methodically, this grackle picks items from the ground and moves leaf litter to find insects, snails, frogs, and cereal grains. Some populations will moisten dry foods. From shallow water, the grackle grabs shrimp, tadpoles, fish, and mussels. The Boat-tailed Grackle will raid other birds’ nests for eggs and young. A variety of human food is scavenged from lawns, dumps, and city streets.
In early spring, female Boat-tailed Grackles scout potential nesting sites and gather in groups that will form colonies in tall grasses, cattails, trees, and shrubs. Males exert control over these “harems” according to hierarchies determined by age. Males or females that are close in rank may fight. Female Boat-tailed Grackles show little fidelity to the older males that guard the harem; low ranking males appear to sire the majority of young.
Female Boat-tailed Grackles build a large bowl in stages, usually on a platform of coarse grasses 3 to 15 feet above water or land. They finish it off with fine plant materials pressed into a layer of mud or animal dung. Females raise the young alone from incubation (13 days) through fledging (12-15 days), and during 5 or more weeks of a protracted juvenile period. Juveniles may learn complex feeding and defensive techniques in flocks of females and young. After approximately a year, males move into separate flocks.
Most Boat-tailed Grackles do not migrate. Northern populations withdraw south of Virginia in the winter, and post-breeding birds in Texas move slightly south along the Gulf Coast.