Hibernation, Migration, and Adaptation

By Sarah Cubells

There are so many things to love about summer in East Idaho. But as we all are well aware, this summer has been particularly hot and dry. As I long for cooler temperatures, I often ponder the astonishing changes the local wildlife species make every year to survive the shifting of seasons.

One of the classic examples is hibernation. Bears, chipmunks, and marmots are among the local species that enter a prolonged snooze to wait out winter months. In general, an animal’s body temperature drops, and its heartbeat and breathing slow down during hibernation. This helps the animal preserve the precious energy it has stored throughout the summer and fall, either in the form of body fat or as food hoarded safely in its burrow for mid-winter snacks.

In Greater Yellowstone, we often hear about wildlife migration, another method animals use to survive seasonal changes. Famously, elk migrate in and out of Yellowstone, numerous bird species come and go seasonally, and native fish make epic journeys to survive. This type of animal movement is observed on many scales. Insects, such as some butterflies and moths, are known to migrate very long distances. There is still so much to learn about how, where, and why animals migrate, and even what the strict definition of “migration” is. The downward movement of some earthworms, beetles, and termites can be considered a “vertical migration!”

snowshoe hare running through snow
Snowshoe hare running through snow

Finally, some animals stay (awake) in the same climate all year and instead, adapt to seasonal changes. These adaptations can be changes in behavior or body. For many species, new, thicker fur is essential to survive colder temperatures. In some cases, this new coat is also a different color. Snowshoe hares and ermine sport their summer-brown coat in the summer, and winter-white coat in the winter. This helps them blend into their surroundings and better avoid predators.

No doubt, Greater Yellowstone is a harsh ecosystem. The nearly endless amount of mechanisms that the native species exhibit to survive here is astounding. And many species use a combination of hibernation, migration, and adaptation to survive! As we endure the heat for a while longer before heading into the cooler temperatures, perhaps we should keep our eyes peeled for some of these fascinating changes in the animals around us.