Waves of migrating warblers are passing through the treetops. Other birds that have arrived include warbling and red-eyed vireos, chimney swifts, and scarlet tanagers.

Noted, too, are mallard ducklings with their mothers; leopard frogs, western chorus frogs, and American toads and their captivating vocalizations; young gray squirrels seen leaving their nests; and red fox kits appearing from their dens to play in the sunlight. With all the wonders of nature around us, make an effort to get outside and observe. Every forest, lake, marsh, and prairie remnant is full of spring signs — evidence that our earth is designed as place for life.

Nerstrand Big Woods State Park, northwest of Faribault, is known for its spring woodland wildflowers. Close to two dozen species including wild blue phlox, violets, trilliums, and jack-in-the-pulpit are evident.

This spring a good share of Minnesota lakes lost their ice covers about two weeks earlier than normal. Typical lake surface water temperatures are between 50 and 60 degrees for the state's fishing opener starting Saturday.

By tradition this huge outdoor event heralds the start of summer. Yes, Minnesota is home to more than 160 species of fish, but the walleye and northern pike get the most attention. The walleye, our official state fish since 1965, has broad distribution in North America, from the Northwest Territories in Canada, eastward to Newfoundland and south to North Carolina and Arkansas. The walleye is named for its pearlescent eye and reflective layer of pigment that helps the fish to see and feed in dim light.

The northern pike is the most broadly distributed freshwater fish in the world. Both the walleye and northern are voracious predators, feeding on a wide variety of fishes including smaller fish of their own species.

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