Catching up with wonders of migration and those South America-bound

Only a few dozen of the 240 bird species that nest in Minnesota stay through the winter. Much has been written about the "why" of bird migration over the years, but given the huge variability of the food supply and the ability of birds to travel long distances, the natural result is migration.

A few of the migrating birds we can see, and sometimes hear, now include common nighthawks, Franklin's gulls, bald eagles, red-winged blackbirds, rose-breasted grosbeaks, Baltimore orioles and the tiny warblers (Canada, golden-winged and Blackburnian are good examples).

Common nighthawks are 10-inch, dark-colored birds with long, pointed wings and white wing patches. They are long-distance migrants, wintering in southern South America. They can be seen circling and diving for insects while headed south, sometimes in flocks of more than 100. They nested on flat, gravel rooftops in cities, on the ground, on rocky outcrops, and on beaches throughout much of the United States and Canada. Now it's time for common nighthawks to seek insects far away.

Baltimore orioles winter in Florida, Central America and the northern part of South America. These orioles are common nesting birds in Minnesota, except in the northeast. They often return each spring to the same territory, but rarely use the same nest. They sometimes take parts of an old nest to build a new one. Baltimore orioles are insect and fruit eaters and have been busy of late at feeders with grape jelly or sugar water. Expect nearly all to migrate by the first full week of September.

The 5-inch Blackburnian warblers are strong fliers, passing through many parts of Minnesota during fall and spring migrations. They spend winters in northwestern South America in open forests, including shade-coffee plantations. The ones that nest in Minnesota do so in the north-central and northwest parts of the state and southern Canada. They settle in mixed deciduous-coniferous forests. Their food consists of insects and berries.

Jim Gilbert has taught and worked as a naturalist for more than 50 years.