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By Katherine Schramek

Intern Naturalist/Teacher

It’s once again that time of year! The final leaves are beginning to drop, animals are staying busy with their winter preparations, and us humans start reaching for our winter jackets. We’re all familiar with hibernating bears and migrating birds, but what do turtles do? The rush to prepare for winter even reaches these slow-moving creatures.

Turtles are ectothermic, or cold-blooded, which means that their body temperature is reflected by the temperature of their environments. As the temperatures cool down, so do their temperatures. In turn, this causes their metabolisms to slow down. If you see a turtle out and about on a chilly day, you’ll notice that they move much slower than they might in the warmer months.

When turtles are finally ready to stop for the season, they enter a process called brumation. This involves burrowing into mud or soft soil at the bottom of a freshwater pond and continuing to slow down their metabolism. When the ice forms a sheet at the water’s surface, oxygen starts to become limited. The water can either become hypoxic (low in oxygen) or anoxic (no oxygen).

Metabolism is so slow at this point that turtles can manage to survive in these low oxygen environments for the winter. However, it starts to form lactic acid in their muscles. Turtles are able to negate this effect by burning up calcium found in their shells and bones. Once spring rolls around with its warm sunny days, turtles return to their usual activities. They find sunny basking spots to help relax their muscles after getting some lactic acid buildup.

This is a vulnerable process where many things can go wrong, and things often do. Forty-four percent of turtle species in Minnesota are threatened or are of special concern. Disease, pollution, harvesting, and habitat loss are some of the biggest threats facing our turtles. The best thing you can do if you spot a turtle on it’s way to brumate is to leave it alone as moving them could disorient them.

This winter, let’s shell-abrate the marvelous process of brumation!

Nature Center Events

Registration for Wreath Class is open online through our website.

Saturday: Pop Up Apple Cider Event, 10-11:30 a.m.

Saturday: Pop up Free Guided Mindfulness Hike, 1-2 p.m.

Nov. 8: Cedar River Astronomy Club, 7-8 p.m.

Nov. 11: Interpretive Center Closed – Trails Open

Nov. 14: Doug Wood Performance, 7-8 p.m.

Nov. 28-29: Interpretive Center Closed – Trails Open