Waiting Out Winter

American toad

Digging Deep to Weather the Cold

Even as cold weather descends, the American toads in the Pritzker Family Children’s Zoo don’t vary their routine much. As icicles form and snow piles up outside, conditions remain constant in their climate-controlled exhibit. They continue to climb their log, munch insects and dig little burrows in the dirt.

For wild American toads, it’s a different story. As conditions get cold, these warty amphibians dig down beneath the frost line to wait out winter. Unlike some other amphibian species, American toads aren’t adapted to survive freezing temperatures, so it’s important they tunnel deep enough to avoid the chill.

When the weather warms in spring, the toads emerge from their burrows to start making their way to the ponds and wetlands where they breed. Males establish territories, using trill-like calls to attract mates. Eggs are fertilized in the water. Tadpoles hatch, grow and transform into the next generation of American toads.

But for now, the species stays hunkered down, waiting for the last frost of the season to melt away. Except at the Children’s Zoo, where it remains spring year-round.


by James Seidler

Other Hibernation Highlights

Eastern massasauga rattlesnake   Massasaugas Take the Season Off
A winter cool down behind the scenes at Regenstein Small Mammal–Reptile House primes endangered eastern massasauga rattlesnakes for spring breeding.
Smooth green snake   A Big Chill
Animals in the wild hibernate in response to winter’s lack of food, shorter days and colder temps.
Humans may not hibernate, but families with children ages 5–12 can grab their nighttime gear and join us for an overnight adventure!