Eating, drinking, existing: Chimney swifts spend life airborne

Ducks and Canada geese are grounded while they molt their wing feathers. We will see them airborne again by late July.

Wild turkey hens are out and about with their small poults. Red mulberry trees are loaded with ripe and ripening fruit. Gray catbirds, American robins and many of us humans relish the berries. Hikers snack on ripe wild blackcap raspberry fruit, and the first garden raspberries can get picked.

Common milkweeds are blooming and fragrant. Farmers are cutting the second crop of alfalfa. The wild lupine, an introduced plant from Washington and Oregon, is blooming inland and has made a dazzling display of blue, purple and pink along the North Shore. Prairie areas across southern and western Minnesota have become colorful with blooming wildflowers such as oxeye, purple prairie clover, black-eyed Susan, and butterfly milkweed. Green frogs are calling, their "banjo playing" happening day and night from calm waters. By 9:40 p.m. American robins are ending their singing and calling for the day, and nearly all chimney swifts are in their chimney roosts.

Chimney swifts breed locally in cities and towns across the eastern half of the United States. From May through summer, chimney swifts chatter, glide and feed on flying insects over Faribault, Le Sueur, St. Paul, Stillwater, Benson, Park Rapids, Bemidji and other Minnesota cities. Observing the fast, erratic flight of chimney swifts is one of those things that makes my day. Most people associate this species with urban areas where chimneys abound, but some swifts in the northern forested areas continue to nest in hollow trees or on the walls of cliffs.

Soot-colored, the 5-inch swallow-like chimney swifts have very short tails and long, narrow, curved wings perfectly adapted for rapid flight and quick turns. They feed exclusively on flying insets, pursuing them through the air with open mouths. Their wing span is about a foot.

Except when roosting, chimney swifts spend most of their lives in the air. So perfectly adapted for aerial life are these "flying cigars" that they drink water and bathe by dipping into the water of a pond or stream as they fly over it. They even court and mate in flight.

Chimney swifts gather nesting twigs in flight, snapping them off with their bill or feet as they pass by trees. Nesting takes place in June. About four white eggs are laid in a small nest of sticks glued together with saliva and attached to the inside wall of a chimney or other surface.

Jim Gilbert's 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.