Common Grackles are omnivorous ground foragers. When snow and ice cover the ground, Common Grackles eat mostly seeds – especially corn, but also rice, sunflower seeds, acorns, sweetgum, and any dried fruit or edible garbage they can find. During the summer, about 25% of their diet consists of animals, including beetles, grasshoppers, caterpillars, spiders, crustaceans, mollusks, fish, frogs, salamanders, mice, and other birds.
Common Grackes breed from mid-March through mid-July. Female grackles use vegetation, twigs, cornhusks, and other items to build their cupped nests, which they reinforce with mud and line with soft materials, including hair. They lay one to seven light-blue to pearl-gray eggs with dark scrawls per clutch and may produce up to two broods per year. Female grackles incubate eggs for 11-15 days and nestlings stay in the nest for 10-17 days before fledging. Both parents feed young, although females do the majority of brooding. Once young grackles fledge, they will have plenty of company – Common Grackles are gregarious birds who often nest in loose colonies and flock with blackbirds, cowbirds, and starlings. To learn more, visit Cornell’s website.
Bird Range Maps of North America
Ridgely, R.S., T.F. Allnutt, T. Brooks, D.K. McNicol, D.W. Mehlman, B.E. Young, and J.R. Zook. 2003.
Digital Distribution Maps of the Birds of the Western Hemisphere, version 1.0. NatureServe, Arlington, Virginia, USA. Data provided by NatureServe in collaboration with Robert Ridgely, James Zook, The Nature Conservancy – Migratory Bird Program, Conservation International – CABS, World Wildlife Fund – US, and Environment Canada – WILDSPACE.
Web Link: http://bit.ly/2ynPQ5I
Adult Common Grackles have dark bronze or black iridescent bodies and glossy purplish-blue or bluish-green heads, necks, and breasts, although they may appear all black from a distance. They have bright yellow eyes, long legs, a long tail, and relatively long beaks with a slight downward curve.
Common Grackles are short-term, partial migrants. They can be found in the Decorah area year-round, although some wintering grackles could be migrants from colder northern areas.
11.0-13.4 in/28-34 cm
14.2-18.1 in/36-46 cm
2.6-5.0 oz/74-142 g
Elliptical. Optimized for bursts of fast, tightly controlled flight. Excellent at taking off quickly, maneuvering through branches, and avoiding predators.