Common grackles can be found in the Decorah area year-round, although some wintering grackles could be migrants from colder northern areas. When snow and ice cover the ground, they 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.
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 eggs per clutch and may produce up to two broods per year. Grackles incubate eggs for 11-15 days and nestlings stay in the nest for 10-17 days before fledging. Once they 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.
Curious about different kinds of nests? You can read more about nests here: http://bit.ly/2rmJC2f