The thermometer topped the freezing point for the first time in more than a week this afternoon. Even a couple of days of thaw weather might melt off and dry area roads enough to risk washing the salt slush off the vehicles. An actual film of salt has formed around wet spots on my garage floor and out on the driveway, where slush and ice chunks fall off the car and truck. It’s a wonder that our rivers aren’t as salty as the oceans with all the salt that’s applied to roads when it snows. The salt prevents some accidents, but dissolves cars almost as well as it does ice.

We may, or may not, see a real spring thaw in the next week or two. The threat of snowstorms is with us well into April. Spring is already stirring, though, but is still mostly unseen. Sap has begun flowing in many of our trees and buds will soon be swelling because of that. It’s the time of year that maples are tapped for making maple syrup. Be listening for the songs of male cardinals. Lengthening days have told them it’s time to begin staking out nesting territories. They’ll still tolerate each other around the bird feeder for now, but soon they’ll start viewing their winter buddies as rivals and won’t tolerate their close presence again until fall.

We have resident eagles in Iowa now, and they’ll be strongly focused on their nest sites in the weeks ahead. They may add a few more branches to the nest and do some “rearranging of the furniture.” That done, most pairs will have laid their eggs before another month passes. Eagle pairs mate for life, but each late winter they go through a period almost like courtship again. It’s as if they’re renewing their vows, as some human couples do around Valentine’s Day. Migrant eagles spending the winter with us go through this, too, even though they may be hundreds of miles from their nesting territory. If you’re lucky and keep an eye out for flying eagle pairs, you may get to watch their famous and exciting courtship dance. They tail-chase for awhile, almost like playing tag, with lots of swooping dives and near misses. One bird will sometimes roll upside down and lock talons in mid air with its mate. They spiral down, still holding each others’ feet. They’ll break away and begin the chase again before actually hitting the ground. It’s amazing that such a large bird can perform such aerobatics.

Great horned owls mate for life, too, and may already be sitting on eggs. Listen for their monotone hooting on calm winter nights. It’s the owl’s equivalent of other bird songs, and is intended to let others of their kind know that they are claiming and will defend their nesting territory. Their very early nesting is timed so that the rest of nature will be providing lots of young, easy-to-catch prey when the owl’s young ones are growing fastest and are always hungry. Owl and eagle young take longer to mature than most other birds, too. They not only have a lot of growing to do, but have to learn the difficult art of aerial hunting before their parents stop feeding them. Those that survive that long will be on their own and able to care for themselves by fall.

Ice on area lakes and rivers is still thick as this week’s column is written, but it’s going to become weaker in the days ahead and will finally disappear. A little rain on our still-frozen soil, or a couple of days of rapid snow melt, may blow the ice out of rivers pretty quickly. Lake ice doesn’t just melt away and get thinner as it deteriorates. Some refer to lake ice as “rotting” in place. It may still be fairly thick, but its solid structure slowly breaks down into long finger-like crystals. A little patch of open water can expand rapidly on a warm, windy, late winter day as those crystals break up. A lake can be completely ice-covered one day and completely open the next. Late winter ice should never be trusted, especially when it’s still covered by snow or frozen slush. Late winter can provide some great ice fishing, but lots of extra caution is required. It might be better to spend that time getting the boat and tackle ready for open water soon to follow.

Steve Lekwa is a former director of Story County Conservation.