Autumn a Time of Preparation 

Getting ready for Winter

Fall is a time of wildlife abundance. Of course, many of the wild animals that seem so obvious in fall do not survive to the next spring. But we can get an appreciation for nature’s amazing reproductive potential when we view the huge flocks of ducks, geese and song birds, the herds of deer, and groupings of other species that dot our state’s autumn landscape. And we can see how various species prepare for a time of scarcity—winter.

Michigan sits squarely in the fall migration path of hundreds of bird species winging their way south. Our state’s shorelines, wetlands, forests, dunes and other habitats are critically important to these travelers. Some species like sandhill cranes “stage” in fall, gathering by the hundreds or even thousands at the same places each year. Around November 1, there are usually still thousands of the birds in well-known spots such as the Haehnle Audubon Sanctuary and the Bernard Baker Sanctuary.

Animals that stay in Michigan don’t congregate like cranes. They must prepare for three to four months of hibernation (like bats and woodchucks) or a difficult search for food in snow-covered or frozen terrain. The survival strategy in either case is to consume as much energy-rich food as possible before the weather turns.

There is a major shift in deer feeding in fall, much to the chagrin of Michigan farmers. Acorns, berries and crops such as corn become more important than the green leaves and grasses that dominate summer diets. In northern Michigan, there is a noticeable movement of deer from summer ranges to preferred fall feeding areas. This movement may be several miles or more. Deer are one of the few mammal species that mate in fall and this also demands energy. Intensive feeding prior to the fall “rut” gives bucks the energy they need to fend off rivals and find does.

Black bears also step up their feeding and accumulate fat reserves in fall. As winter approaches, they seek spots to rest in a sort of sleep. Contrary to popular belief, they don’t need caves for dens. Females about to give birth usually select tree or stump cavities, or openings under brush piles or rock ledges. Young males often den in similar spots, but large males may simply use their claws to rake up piles of leaves and sticks resembling a bird’s nest, and then spend the winter on top of the pile. Some males just lie down in very dense shrub growth without preparing any kind of winter bed or nest. In Northern Michigan, bears are searching for or occupying denning areas by mid-November.

The tiny eastern chipmunk manifests another variation of the hibernation theme. Although it can lower both heart rate and body temperature, it does not accumulate much body fat in fall. The chipmunk stores food near its nest of leaves in a cavity or crevice, which it will feed on when it awakens periodically. There is a lot of difference in the individual winter behavior of chipmunks. Even when they are all in their dens, some individuals are wide awake and have stores of food, while others are completely dormant in a deep sleep with no food stores nearby. So, some chipmunks are a lot busier gathering food in fall than are others.

No matter what species interests you, autumn is a great time to observe wildlife. Most species are on the move and the dropping of fall leaves makes them more visible. Great information on Michigan’s better wildlife observation spots is available at www.michigandnr.com/publications/pdfs/wildlife/viewingguide.

One of the featured spots on this website is the Milli-Ander Wetland Restoration, the Michigan Wildlife Conservancy’s first major project. Completed in 1984 and located north of St. Johns along US-127, the wetland hosts thousands of waterbirds and song birds in fall. It is open to hunting and wildlife can be viewed from several access sites.

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