Live or Die: Activities for Learning How Mammals Survive Winter
You’ve seen the look – that middle school bored stare that says, “I’ve already learned all this.” That’s what I am facing in presenting several lessons on winter ecology to seventh graders this winter. These are students who have been coming to our nature center since they were in kindergarten, so there is some justification to their reaction. But their exposure to the topic hasn’t been extensive so I just need a hook to get them interested and engaged. The answer? Make it a competition to see who survives.
These students like games and are very competitive, so I’ll use three different kinds of activities – a game, a demonstration, and an experiment – that provide them with experiences to mimic real-life behaviors and challenges faced by Minnesota mammals dealing with winter conditions and we’ll see, at the end of each activity, how well they did to survive. At the same time, we’ll use their observations to deepen their understanding of what happens to animals that hibernate or stay active. Since I teach consecutive classes that are only 50 minutes long, the activities need to be easy to set up and use equipment that can be reused multiple times.
During the year, my lessons with the students have focused on energy use within ecosystems. This topic is a perfect tie-in to winter ecology, so I am planning activities that will give students experiences with how energy is used and conserved by animals that are hibernating* or staying active. (*The concept of hibernation is not clear cut in the scientific world. In researching this topic, I found a range of definitions and qualifications as to what constitutes a “true hibernator” over a “shallow hibernator” or an animal that is in torpor. For the purposes of these lessons, I am using the word “hibernation” to mean a state of decreased metabolic rate and physical activity. This will tie into the on-going discussion of energy use and conservation without getting hung up on nuances of the terminology.)
The Game: HIBERNATION: WHO WILL SURVIVE?
This game gives students an understanding of the importance of eating enough for an animal to survive hibernation. Students will move from station to station, rolling dice and recording the number rolled on data sheets. The numbers are totaled and represent the amount of food eaten by the animal in preparation for hibernation. The data sheets are coded to represent four different animals – black bear, ground squirrel, woodchuck, and little brown bat. One animal at a time, the food totals are listed for students to see. Then the teacher shares with the students how much food had to have been collected for the animal to survive hibernation. Part of debriefing the game will include a discussion of the function of eating and how animals put on different kinds of fat that help them survive. We’ll also discuss other strategies and adaptations that take place during hibernation (e.g. clustering, awakening and eating, periodic rousing in order to fall back into a deeper sleep).
The Demonstration: ENERGY IN, ENERGY OUT
Animals that remain active during winter need a certain amount of food each day to survive. For example, deer need to eat five pounds a day for every 100 pounds they weigh. In this demonstration, students will see how three different animals expend energy to collect the food they need. A small group of students are chosen to represent the animals: mink, feral cats, and coyotes. The “animals” will begin on one side of the room with “food” being on the other side of the room. At a signal, each kind of “animal” begins collecting “food” according to the approach it uses in the wild – mink eat frequently throughout the day while cats only need to eat a couple of times a day, and coyotes will eat daily, if possible, but tend to exist on a feast-or-famine approach. What the students will notice as the food collection is happening is that the mink are moving constantly, the cats move a little less often, and the coyotes work hard for a little while and then have lots of time to rest. In debriefing the demonstration, we’ll talk about the challenges winter-active animals face in needing to expend energy to get energy and what kinds of things can impact them (e.g. competition over resources, weather conditions, predation).
The Experiment: BABY, IT’S COLD OUTSIDE
A third activity will look at energy loss as mammals work to maintaining body heat. Students will be measuring the change in temperature among a group of containers that represent different strategies used by mammals in cold climates. Hopefully, they will apply knowledge they learned in the earlier activities to be able to predict which containers will maintain temperatures the best. Students will be given plastic containers of different sizes containing water that is 100°F/38°C. Some containers will be placed in bags that provide additional layering. (See complete directions at the end of the article.) The groups place their containers outside within a given area for twenty minutes. Then they’ll measure the temperature of the water inside the container and compare their findings to see how size and layering impact the ability to maintain a constant temperature. For this activity, we will not be able to easily identify who survived and who didn’t. Part of debriefing the activity will be to introduce the idea of the subnivean zone and that even small animals can conserve energy by making use of the insulative properties of snow. The broader point of the lessons will be to help the students see there is not a one-size-fits-all approach to survival in winter.
By the time we finish this series of activities, students should have a better understanding of the critical role energy use and conservation play in hibernation and staying active in winter. And, hopefully, they will have enjoyed the way they learned about it.
For full activity descriptions and directions, please visit our Environmental Education Corner.
Teresa Root is a Naturalist and the Naturalist Fellowship Coordinator at the Dodge Nature Center, West St. Paul, MN. She can be reached by email at firstname.lastname@example.org