Early mowing of hayfields destroys many nests. The three to five eggs are white, heavily blotched with brown. The female incubates her clutch for about two weeks. After the young hatch, both parents feed them insects. Fledglings leave the nest after 10 to 12 days and are fed by their parents for another two to four weeks.
Some females raise two broods over the summer.
In August, meadowlarks abandon their breeding territories and forage in small flocks. In September and October most shift southward, migrating at night and feeding during the day. Some meadowlarks winter in eastern and western Pennsylvania, although most go farther south. The population has declined in the Northeast over the past 40 years as development has wiped out agricultural land and formerly farmed areas have grown up into brush and woods. Grackles are sleek black birds with iridescent purple, green and bronze highlights in their plumage.