The first common grackles arrived March 22 this year. We heard their high-pitched screeches, which sound like rusty hinges on a garden gate, and saw these blue jay-sized black-colored birds flying by. Yes, the grackles were back for another growing season.

Its early spring arrival, habit of feeding on lawns, and frequent appearance at feeders combine to make the common grackle one of our best-known birds. They may appear uniformly black from a distance, but they are highly iridescent at close range. Their colors vary from purple and blue to green and bronze. The bright yellow eyes are easy to spot with binoculars or when the birds are close. Males have slightly longer tails than females, and more iridescence on their heads and necks.

Grackles are members of the blackbird family. They are classified as songbirds not because of the beauty of their songs but because they have all the vocal equipment a songbird needs. Birds do not have vocal cords. All of their sounds come from a resonating voice box down at the bottom of the windpipe, just where the bronchial tubes branch off to the lungs.

Now near the end of May, we notice many young grackles on our lawns, fresh out of their nests. These young fly well soon after leaving the nest, and are fed by their parents for only a few days. After that, they join with other juveniles to form flocks that feed and roost together. Later in the summer, they join bigger roosts of adults and juveniles. Common grackles produce only one brood each year.

These grackles rank high in intelligence. Like the American crows, they are omnivorous. They can be seen, for example, in shallow water along lakeshores and streams, looking for minnows, their tails elevated to keep them dry. I have even seen grackles fishing at minnow tanks in marinas. More often they feed on cutworms, beetles, crickets and various insects, which could harm farm and garden crops. In addition, they feed on the seeds or noxious weeds.

Jim Gilbert's Nature Notes were heard on WCCO Radio at 7:15 a.m. Sundays for more than 40 years. His observations have been part of the Minnesota Weatherguide Environment Calendars since 1977. He taught and worked as a naturalist for 50 years.