Winter to Spring Transition: On the Cusp
At first glance, Wisconsin in late winter might seem like a world frozen in time, hibernating under a white blanket, but there is more than meets the eye! Slowly, but surely, nature is starting to make moves. This part of the year is very much like the moment at the end of a meditation when the mind reluctantly begins to come back to the body and take in the surrounding sounds. March is very much like a wiggling of the fingers and toes.
If you have seen a time-lapse of leaves uncurling, then you know that even when it seems like nothing is happening, plants are on the move. Even now, when there are no leaves, there are, in fact, signs of life. Many plants are starting the slow transfer of stored sugars and minerals from their roots up to their shoots where, if you look closely, you will see leaf and flower buds beginning to form. Silver Maple is one of the first spring flowers and some are already close to blooming! Catkins on birches and Ironwood are growing. Leaf buds on many other trees and shrubs are beginning to swell. In Sugar Maples, the spring movement that occurs under the bark up the trunk is what we tap to create Maple Syrup. The running of the sap is as close to wiggling its toes as a plant can get.
Where It’s Sap
Yellow-bellied Sapsuckers arrive roughly in time with the imminent start of the maple flow. They drill shallow holes called sapwells in horizontal rows on trees, feeding on the insects and tree cambium it digs up in the process of drilling. These birds have been observed drilling sapwells in hundreds of species. The trees they prefer may vary according to the region, but examples include American Elm, Musclewood, Basswood, and many species of maple and birch. They maintain these holes so that they do not close. It should be noted that these sapwells rarely harm the tree. Other wildlife depends on the sapwells. The Ruby-throated Hummingbird can rely heavily on these sapwells. In fact, in many locales, their migration occurs just after the Yellow-bellied Sapsucker’s arrival so that these sapwells will be available until the spring blooms appear. Bats, other birds, and even porcupines also visit sapwells made by sapsuckers. Yellow-bellied Sapsucker Overview, All About Birds, Cornell Lab of Ornithology. Many factors trigger migration, and photoperiod (day length) is one. Inevitably, there will be times upon their arrival when the temperature is not yet high enough to trigger the flow of sap. In these cases, the Yellow-bellied Sapsucker survives by feeding on the bast, the inner cambium of the tree, which provides a fair bit of nutrition.
Learn more about Yellow-bellied Sapsucker (allaboutbirds.org).
Soon enough, the spring ephemerals will begin to sprout and bloom, signaling spring is here in earnest and a promise of the bounty that is to come. Until we receive those precious bits of color and joy, year-round residents and early-arriving migratory birds will need to make due.
Fruits, Nuts, and Seeds Oh My!
Wisconsin’s year-round residents switch to a “winter diet” as summer resources dwindle. The Black-capped Chickadees just started singing in February, but they are active all winter long and one of the few birds that you may have noticed, even if you do not consider yourself a “bird person.” Their summer diet consists largely of insects, which are much harder to find in the winter and so make up much less of their diet during this time. While they can glean insect eggs and larval forms under bark and in the fall leaf layer, at this time of year grass seeds and the seeds of other perennials, as well as fruits, make up most of their winter diet. The same is true for other common winter birds, like the Dark-eyed Junco. The White-breasted Nuthatch also leans on available acorns and Hawthorn berries.
Very soon, migratory birds will begin to arrive in Wisconsin in droves. You may have already heard a few new songs in your neighborhood! Though not all Sandhill Cranes leave Wisconsin, most do and migrate back in March. Step out of the house at night when all else is quiet and you might hear the Sandhill Cranes flying overhead. Eastern Bluebirds, Red-winged Blackbirds, and Eastern Meadowlarks are also making their way back. While insects make up most of their summer diet, remember, that insects are dormant in the winter months, usually as eggs or larvae. As they arrive, they make due by feeding on seed at the tail end of winter until insects finally begin this year’s cycle. Eastern Meadowlark, among others, just mentioned, relies heavily on grass seed at this time. On this note, if you have planted grasses in your yard, it is extremely helpful to leave them alone. The foliage provides shelter and nesting materials while the seed heads provide vital winter food to many birds and small mammals. Countless native perennials, shrubs, and trees such as oaks, hickories, hazelnuts, coneflowers, and grasses all provide seed throughout the winter.
Looking out the window it may seem like an uninhabitable tundra (misnomer btw, with much respect to those eking it out above the Arctic Circle!) Despite this, February and March bring the arrival of migratory American Robins, Belted Kingfishers, Song Sparrows, Wood Ducks, Killdeer, Hooded Merganser, American Woodcock, Canada Geese, Bald Eagles, Eastern Phoebe, and more! American Robin, Grey Catbird, and Eastern Bluebirds eat fruits where available currently. While some shrubs and trees provide berries in the middle of the summer, others ripen in the fall and persist through the winter. Winterberry, Hawthorn, sumac, Chokecherry, Glossy Black Chokeberry, American Bittersweet, Eastern Redcedar, Oldfield Common Juniper, crabapple, Alpine Currant, wild grape, and more, even Common Elderberry if it lasts long enough, can all collectively provide carbs until spring, when more will be available.
A Safe Place
Plants not only provide sustenance but often they also provide the only shelter available. A crazy number of animals use tree cavities as shelter in the winter months. As you read this, squirrels, porcupines, mink, raccoons, opossums, and more are gratefully using hollows in Basswood, Sugar Maple, Black Cherry, and White Oak as shelters. Birds and even bats are using cavities, cracks, and even loose flakes of bark hanging off the trunk as shelter. Woodpeckers will often build their nests in hollowed-out portions of tree trunks or will DIY their hole by drilling into the wood and chipping away at it.
How We Can Help
Before cleaning up the landscape in the fall, try to leave a little mess. Remember that animals are extremely resourceful but if there is nothing left then they have nothing to work with. So leave that flaky bark. If you must rake, then consider leaving a pile of leaves in a corner of the yard. The insects these animals will feed on come spring are currently spending winter under bark and in leaf litter. Pruned branches piled in an unused corner can serve as shelter for small rodents and reptiles that need a safe space to bromate or go into torpor. (PSA-Check brush piles left to sit a while should be checked first for creatures before being burned. Also, lightly sift through compost before using a shovel or pitchfork). If a tree dies, leave the trunk in place as a habitat for wildlife—when you look around your city you may find examples of this done creatively by others. If this is not an option, consider providing boxes for Wood Ducks, Eastern Bluebirds, Barred Owls, American Kestrels, and bats, which could not only serve as shelter for some winter residents but can do double duty as a nest box for animals in spring. Do not forget to clean them out annually!
This secret winter life that occurs mostly while we hide in our houses, walking from house to car to store and back, largely relies on plants. Those days we ironically call “cozy” are in reality brutal and life-threatening for our small friends. Many of the creatures out there are surviving (or trying to) off of the decisions that you make in your landscape. So, when landscaping with wildlife in mind, think of your whole yard as a garden and cater to as many species as possible by providing as much diversity as you can. A quote by Doug Tallamy is rather famous for saying it best: “Garden as if life depends on it!” Because indeed it does.
Spring is almost upon us! Please keep the plants mentioned above in mind as they will provide for wildlife at a time when we have put down our trowels and watering cans to hunker down indoors. Plant more natives and aim for diversity. Choose groups of plants that provide nuts, berries, and shelter. Design with every season in mind by asking yourself if there will be resources available year-round within the group of plants you have put together. Imagine if all of your neighbors did this as well! Read our Bird Garden guide for a list of valuable plants! The following are some plants that will help carry wildlife through late winter, just before spring has finally sprung.