During the winter months, life gets interesting as the Northern Hemisphere is tilted away from the Sun and the days are shorter and colder. The further north you go in the United States, the more animals and plants are obligated to respond to the cold and reduction of food. Birds may leave breeding grounds and fly south, mammals hibernate or scavenge the foods that remain, and plants go dormant to protect themselves from freezing. It is a quieter time, but the world is still alive!
Winter brings freezing temperatures to northern temperate regions. Animals living in those regions have various strategies for survival. Some can migrate to warmer areas. Others store food in caches to sustain them through the cold months, and some animals pass the winter in a condition of metabolic torpor called hibernation.
People today often think of winter as a time that must be endured until Spring. The usual strategy is to stay warm by staying indoors. OBIS offers winter activities to entice educators outdoors to take advantage of learning opportunities found in nature only on winter days.
Acorns simulates different strategies of food storage. In a game context, participants simulate the behavior of either red squirrels (that store all their winter food in one location), or gray squirrels (that store food in several locations). Each month of winter is a “round” during which time the “squirrels” must locate and consume a specified number of acorns in order to survive. At first the squirrels are allowed to use only their own caches, but as winter continues and food becomes scarcer, squirrels begin to poach food from the caches of other squirrels. In the end the participants evaluate the effectiveness of each caching strategy.
During hibernation, animals exhibit a dramatic reduction in metabolic activity—body temperature, heart rate, and breathing rate all decline. Hibernation is a demanding way to pass the winter. One of North America’s champion hibernators is the black bear. Capable of going 100 days without eating, drinking, defecating, urinated or exercising, their heart rates can drop from 40–50 beats per minute (active summer) to 8 beats per minute (hibernating). Male black bears can lose 15–30% of their body weight over the winter while nursing females can drop as much as 40% of their fall weight. To sustain long periods of time without food, it is essential for hibernating animals to select a protected spot (a cave or den) that is naturally insulated. To learn more about hibernation try Animal Antifreeze, where participants are challenged to search for hibernation sites that will best protect their liquid gelatin “animals” from freezing.
The amount of food available to a population of animals has a life-and-death impact on the number animals that can survive the winter. Population Game introduces the concept of carrying capacity—how a food resource defines the size of a population in an area. Participants (deer) forage for enough “food” (counting chips) to survive the round. If a deer survives, it reproduces, doubling the surviving population. Eventually the growing population exceeds the capacity of the habitat to produce enough food for the growing population of deer. It is a scenario playing out all over the country with the overpopulation of deer overgrazing urban and suburban woodland habitats. In the final round, the idea of migration to new feeding areas is introduced as one way that a population can cope with a food shortage.
Pull on your snow boots and trek out for an activity in a snow-covered landscape. Winter can provide a fresh canvas on which animals have drawn a picture of their travels for you to observe and interpret. After a fresh snowfall, footprints betray wildlife stories that usually remain obscure. But even with the help of snow to expose footprints, a world of animal interaction in the form of scent eludes humans.
Scent Tracking simulates that world, as participants become either hunted deer or hunting wolves. The “deer” are given a bottle of diluted extract-scented liquid (lemon, coconut, peppermint, etc.), with a hint of yellow food coloring. The deer spray the liquid in the snow about every ten paces as they wander off to seek a hiding spot. Each deer has a different scent. Each “wolf pack” (team of 2–3 kids) is given a cup of scent-marked snow to identify the deer they will track. Crisscrossing deer trails enhance the challenge of tracking a specific quarry. Students use their smell sense to map the movements of a specific deer in its territory.
An outdoor excursion during winter can often provide a much needed infusion of fresh air, sunlight, and physical activity while awakening your senses to the opportunity to make new discoveries. Try these activities from OBIS as a way to draw your participants into an amazing world of winter survival and beauty.
Activities highlighted in this article:
Acorns
Animal Antifreeze
Population Game
Scent Tracking