I've got a lot on my mind this time of year:

Otters bound and slide over the snow to travel quite long distances with little effort.

Eastern cottontail rabbits emerge shortly after sunset to feed on the twigs of small trees and shrubs.

Gray squirrels will use wood duck nesting boxes for sleeping, several squirrels to one box.

By mid-February, motorists in the southern half of Minnesota often see flocks of the small, grayish-brown horned larks along roadsides and in fields. These are the first of the spring bird migrants each year and are usually in groups of three to 20 that flit up as a car passes.

This is a good time to get out and prune apple trees. Winter or early spring pruning before growth starts is best for helping to speed up healing, too. Cuts made in warm weather could invite disease. Pruning is done to limit the number of apples a tree will produce, so the fruit will be of good size. Pruning also opens the tree so sunlight can penetrate the interior and ripen the fruit.

Tree squirrels like fox, flying, red and gray have started their mating seasons. More raccoons and skunks are moving about the landscape. In Minnesota and Wisconsin, they usually "den-up" in early winter and remain inactive for several weeks. So if you smell a skunk or see a raccoon, mark your calendar — these are spring signs.

The third week of February I begin to listen for the hollow mournful cooing sound of the mourning dove. It's the males that produce the distinctive four-part song: coah, cooo, cooo, cooo. Forty years ago a wintering mourning dove was a rare sight in the Twin Cities and area. Now they are quite common at feeding stations in southern Minnesota throughout the frozen season. However, most still head in autumn for the southern part of the United States.

Reports from avid birders confirm that the mourning dove's winter range is moving north, year by year. Our warmer winters and proliferating feeding stations no doubt account for their extended winter range.

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