The Great-tailed Grackle or Mexican Grackle (Quiscalus mexicanus) is a medium-sized, highly social passerine bird native to North and South America. A member of the family Icteridae, it is one of 10 extant species of grackle and is closely related to the boat-tailed grackle and the extinct slender-billed grackle. Great-tailed grackles are medium-sized birds (larger than starlings and smaller than crows; 38 cm (15 in)-46 cm (18 in)) with males weighing 203 g (7.2 oz)-265 g (9.3 oz) and females between 115 g (4.1 oz)-142 g (5.0 oz), and both sexes have long tails. Wingspan ranges from 18.9-22.8 in (48-58 cm). Males are iridescent black with a purple-blue sheen on the feathers of the head and upper body, while females are brown with darker wings and tail. Adults of both sexes have bright yellow eyes, while juveniles of both sexes have brown eyes and brown plumage like females (except for streaks on the breast). Great-tailed grackles, particularly the adult males, have a keel-shaped tail that they can fold vertically by aligning the two halves.
The great-tailed grackle and boat-tailed grackle were considered the same species until genetic analyses distinguished them as two separate species.
Great-tailed grackles are noted for their diverse foraging habits. They extract larvae and insects from grassy areas; eat lizards, nestlings, and eggs; forage in freshly plowed land; remove parasites from cattle, and eat fruits (e.g., bananas, berries) and grains (e.g., maize, corn on the cob by opening the husks). They turn over objects to search for food underneath, including crustaceans, insects, and worms, they hunt tadpoles and fish by wading into shallow water, and although they do not swim, they catch fish by flying close to the water’s surface, and are even reported to dive a few inches into the water to retrieve a fish. They are also known to pick dead insects stuck to the license plates of parked cars, and kill barn swallows while flying.