Masked Biologist: Getting a Jump on Spring

Feb 17, 2020

No doubt we are in the middle of winter here in the Northwoods. At the same time, though, wildlife is looking forward to spring, and we can do some advance work to prepare for its arrival. The Masked Biologist shares some timely reminders in this week’s Wildlife Matters.

We are well through January now, but winter is far from over. We will turn the calendar page a couple more times before we can even start to believe spring is on its way, right? The last two years, we have had snowfalls in April. In April 2018, we had a snowstorm that broke long-standing precipitation and snowfall records. One year later, in 2019, Rhinelander experienced another snowy April, breaking the record for seasonal snowfall, April snowfall, and giving 2019 a head start toward the snowiest calendar year on record which wrapped up at over 133 inches.

Maybe you don’t need a reminder that winter is ongoing. All you have to do is look out the window, or scrape off your windshield, there’s plenty of winter in every direction. On the surface, or from the road, lake, or snowmobile trail, it may look like the winter has the world in its grip. It’s easy to start to take the woods for granted when a thick blanket of snow covers everything in sight. At the same time, I would point out that spring is on its way. Bears in dens are giving birth to cubs. Bald eagles are starting to return to their nesting sites to strengthen pair bonds and repair or add to their nests. Owl courtships will be starting as well. Mammals that overwinter in dens will be giving birth in the coming weeks, and our earliest long-distance migratory birds will be starting to work their way North from the tropics.

So, a friendly reminder that if you start to get a bit winter weary, you could always start to prepare for spring. I had a friend that found a bat in their house recently. This bat was probably trying to snooze the winter away in the attic or walls, and mistook a warm day for a spring thaw. Bat numbers are in drastic decline due to white nose syndrome, so their roosts are protected during their reproductive season. However, right now you can plan and conduct your batproofing activities before the bats come back to their summer roosting sites. Remember, they can squeeze through any crack wide enough to fit a pencil into; if you go into your attic or crawlspace during daylight hours, you should be able to see the light coming in through the gaps and treat them with caulk or expanding foam. It may be a bit cold, but I would rather be a bit chilly in the attic than roasting!

Another preparation activity could be pruning your oak trees. We have oak wilt here, and hundreds of years of growth can end with an infestation caused by a wound in your tree. If your oak tree is cut or pruned when the sap is flowing and the bugs are out, there are beetles that can smell that sap and will be attracted to the tree. If they are flying from an infected tree to a healthy tree, they can carry the spores of the fungus that causes oak wilt with them. Consequently, foresters and loggers work with what they call oak wilt restrictions to minimize the risk of the fungus establishing in the stand. Unfortunately, it can also spread through the root system so it only takes one tree to introduce it to any other oak trees that may have overlapping root crowns. The seasonal restrictions occur from late spring to early fall, but right now is completely safe at least from a sap eating beetle perspective. I have a bit of a hard time sometimes remembering which branches are live and which are dead; if you are at all unsure, I recommend calling a tree trimming company.

Some other reminders—midwinter thaws mean birds will start to die from salmonellosis, caused by mixing fecal matter with food and water, either around bird feeders or melted puddles where they congregate. Make sure you clean your feeders, spread them out a bit, maybe rake the hulls and bird droppings into the snow a little bit…and put out fresh water in bird baths. This is also a good time to clean out your birdhouses and make sure the breather holes are cleaned out. You will be glad you jumped on those chores before spring arrives!