What's happening in Minnesota's natural world this time of year? A lot.

Northern flickers and flocks of blue jays and American robins are migrating through Minnesota. With clearing skies and northwest winds, expect to see large numbers of raptors and non-raptors passing over Hawk Ridge in Duluth.

Whitetail deer have put on their gray-brown winter coats. Muskrats build mounded shelters in permanent ponds. Young snapping turtles have been hatching from eggs deposited in sunny, dry soil locations last May into June, and finding their way to permanent waters where they will first feed and then hibernate under ice covers.

Fall foliage colors are coming on fast. Examples include bright reds seen on sumacs and red-osier dogwood shrubs and reds on Virginia creeper vines; reds and burnt-orange on sugar maples leaves; and golden-yellows on green ashes and eastern cottonwoods. Garden roses, chrysanthemums and dahlias have showy flowers. Garden flowers such as zinnias, Mexican sunflower, Autumn Joy sedum and New England aster continue to attract the last of the migrating monarch butterflies, our official Minnesota state butterfly since the year 2000.

Monarchs travel south as singles. After a long day of flying they may gather with other monarchs in a communal roost.

At an average flight speed of 11 miles per hour, the first monarch butterflies reach their wintering sites close to Nov. 1 in the mountain forests west of Mexico City. They do make many stops to feed on flower nectar. Monarchs fly anywhere from ground level up to 7,000 feet, the cruising altitude of many light airplanes. In migration they save energy by riding thermals: rising air masses that lift them to favorable altitudes. Their soaring skills are so efficient that many arrive in Mexico fat and healthy, having gained weight on the trip.

Apple season is at its peak. Many varieties of apples are grown in Minnesota, each with its own special flavor, texture, and sweetness or tartness. An apple contains about 85% water, vitamins A and C, plus minerals and fiber, which makes it a healthy snack or part of a meal. This week, Denny and Lynn Havlicek at their orchard near New Prague are picking ripe Red Haralson, Keepsake, Fireside, Sweet Sixteen, Honeycrisp and SweeTango. They are all University of Minnesota introductions. Denny sells 11 apple varieties at Minneapolis-area markets.

Starting a week ago, the common milkweed pods first opened, and now continue to shed their brown seeds on silver-white parachutes. American bittersweet, a native Minnesota vine found in the north and south, has fruit that is orange and crimson. The green fruits (nuts) from butternut and black walnut trees, both native to southern parts of the state, continue to drop.

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