Great-tailed Grackle (Quiscalus mexicanus) Identification Also, grackles will pull up sprouting corn. Damage to Crops ĭamage is similar to that of redwings however, grackles will feed on mature field corn in the dent stage, removing entire kernels from the cob. Reproductive and survival rates are similar to redwings. Grackles often roost with red-wings, but are more partial to roosting sites in upland deciduous or pine trees. Grackles have a larger, stronger bill than redwings, allowing them to feed on acorns and other tree fruits in winter. Its diet occasionally includes small fish, field mice, songbird nestlings, and eggs. The common grackle’s diet is somewhat similar to that of the redwing, but the grackle is more predatory. These birds winter in the southern United States, often in association with redwings, cowbirds, and starlings. Flocks feed in fields, lawns, woodlots, and bottomlands. Range and HabitatĪ common nester throughout North America east of the Rockies, the common grackle nests in shelterbelts, farmyards, marshes, and towns. The male, slightly larger than the female, has more iridescence on the head and throat (Fig. The common grackle (Quiscalus quiscula) is an iridescent blackbird, larger than a robin, with a long, keel-shaped tail.Īn iridescent blackbird larger than a robin, the common grackle has a long keel-shaped tail. These birds provide some benefits by feeding on harmful insects, such as rootworm beetles and corn earworms, and on weed seeds, such as Johnson grass.įig. Red-winged blackbirds can cause considerable damage to ripening corn, sunflower, sorghum, and oats in the milk and dough stages, and to sprouting and ripening rice. Females will often renest if their initial nest is destroyed. Eggs hatch after 12 days of incubation the young grow rapidly and are ready to fledge about 10 days later. Females have 3 to 5 eggs in their open-cup nests made of grasses and other vegetation. This high mortality rate is offset by a reproductive rate of 2 to 4 young fledged per female per year. Annual survival rate is only about 50% to 60%. Except during nesting season, redwings congregate in large nighttime roosts in marshes or woods containing up to several million birds. Males and females often forage in separated flocks, with females being more insectivorous than males. Insects are the dominant food during the nesting season (May through July), with the diet shifting predominantly to grain and weed seeds in late summer through winter. Redwings winter in the southern United States. Large flocks feed in fields and bottomlands. 1).Īn abundant nester throughout much of North America, the red-winged blackbird nests in hayfields, marshes, and ditches. The smaller female is brownish, resembling a large sparrow (Fig. The male, a little smaller than a robin, is black with red and yellow shoulder patches. Summarized below for each of seven species of blackbirds is information on identification, geographic range, preferred habitats, feeding habits, general biology, and damage. The species also have many important differences in their nesting biology, preferred foods, migration patterns, and their damage and benefits to agriculture.
Sometimes they are joined by non-blackbird species, notably European starlings ( Sturnus vulgaris) and American robins ( Turdus migratorius). These flocks and roosting congregations are sometimes comprised of a single species, but often several species mix together. Outside of the nesting season, blackbirds generally feed in flocks and roost at night in congregations varying from a few birds to over one million birds.
The relative proportions of these food groups, however, vary considerably among species. All blackbirds have an omnivorous diet consisting primarily of grains, weed seeds, fruits, and insects. The males are predominantly black or iridescent in color. The various species of blackbirds have several traits in common. In addition to blackbirds, this subfamily includes orioles, meadowlarks, and bobolinks. The term blackbird loosely refers to a diverse group of about 10 species of North American birds that belong to the subfamily Icterinae. The female resembles a large sparrow more than a blackbird. The black male, with red and yellow shoulder patches, is about 40% larger than the female. The red-winged blackbird ( Agelaius phoeniceus) is the most abundant bird in North America. Blackbirds | ICWDM | Wildlife Species Informationįigure 1.
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