The air is filled with the sounds of birds in April. We hear the loud rattling of belted kingfishers, the winnowing of the common snipe in flight, woodpeckers drumming, the chattering of tree swallows, mourning doves cooing and Canada geese honking. Added to this is the “cheer-up” song of the American robin and the melodic accomplishments of the song sparrow. The song sparrow sings three or four repeated notes followed by a rich and varied chuck-chuck warble — put into the English language it might come out as “Marge-Marge-Marge, put-on-your-TEA-kettle-ettle-ettle.” There are hundreds of variations on this basic song sparrow theme.

Why do birds sing, call or make mechanical sounds? It’s how they communicate with other birds and the world around them. The chief function of song in most species is to proclaim territory. It warns males to stay away while attracting females, plus it strengthens the bond between the mated pair. There are social songs such as a canary-like one used by American goldfinches in flock formation. At times a bird sings because it is bubbling over with the pure joy of living. Call notes are used in a variety of situations. There are calls of alarm, anger, scolding and location. As an example, the cheeps of warblers help these nocturnal migrants stay together in flight.

Even though birds do not call and sing for our benefit, we can still enjoy their efforts. It keeps us in tune with the changes coming our way, especially in the spring.

Jim Gilbert’s Nature Notes are heard on WCCO Radio at 7:15 a.m. Sundays. His observations have been part of the Minnesota Weatherguide Environment Calendars since 1977, and he is the author of five books on nature in Minnesota. He taught and worked as a naturalist for 50 years.