Freezing Frogs

​Did you know that some of our Northeastern Ohio frog friends appear to turn into frozen popsicles during the winter months? Yes, you read that right! Native Ohio tree frogs and one of our terrestrial frog species completely freeze their bodies during the harsh winter temperatures, with only their vital organs remaining unfrozen!  

Let’s meet these freezing frog friends!

The Tree Frog Freezers

The Magic of Freezing Frog

​In the dead of winter when the land is still and the wind chills you to your core, the earth is blanketed with a fluffy white comforter that has transportation tunnels for mammals channeling through its deep layers. While mammals are hibernating and amphibians and reptiles are either bromating (like hibernation, but for the cold-blooded creatures) or experiencing torpor (slowed metabolic rates), these popsicle frogs let their entire bodies freeze except the vital organs they use to keep them alive. As the days get shorter and the temperatures drop, this is the sign that wildlife use to go find a safe hiding place for the winter months under a leaf pile, in a hollow tree, a burrow underground and even underwater for the aquatic creatures. 

The Terrestrial Frog Freezer

As the air crisps and their little bodies begin to convert from frog flesh to frog popsicle, natural antifreeze works its way to vital organs for protection. Ice is formed in the extracellular spaces (outside the cells) while keeping ice from forming inside of the cells. These amphibian antifreeze agents are made up of cryoprotectants like glycerol, glucose, and urea that help hinder cellular and tissue damage caused by the ice. Tree and terrestrial frog freezers stay in this suspended animation of this freeze tolerance strategy where they experience reduced metabolism, helping to conserve energy during the cruel cold chill.
 
Temperatures begin to warm; the frog popsicle begins to slowly melt. While water drips back into the frog’s cells their metabolic processes slowly restart. The organs assume their normal duties, and finally when the frog’s heart beats again, it begins to magically move.  Sudden urges to stretch its long stiff legs and exercise its exhilarated and grateful voice rush throughout our frog friends. They are off to find a humbling new home and a heartwarming meal.
 
While you are out on your whimsical winter wanderings, pause for a second and think about our exquisite, ecologically essential Northeastern Ohio frogs that seem to be frozen in time. Create space in your mind to think about what creatures lie beneath the snow, waiting to “thaw” out when the weather warms up, and get excited about natures frog’s hop back to life – for love season is creeping around the corner!

!!CALL TO ACTION!! All readers- please share your frog sightings!
​
 iNaturalist is a citizen science app that helps observers collect flora and fauna data that is used by our local parks =) 

Author:

Kendra Heiser is the Furnace Run Watershed Coordinator at SSWCD.