Feeling Froggy, Feeling Frozen
Animals in nature have so many fascinating hibernation tactics.
Howdy! It’s Joey, back with more Fun Fact Friyay. I hope you’re bundled up and perhaps reading this with a mug of hot cocoa, because we’re about to get chilly.
Wood frogs spend the winter frozen.
Much of the world is in the midst of very cold temperatures. Since it’s below 32 degrees Fahrenheit as I write this (or zero degrees Celsius), I can honestly say that it is freezing outside.
You might even have uttered something like, “Good golly, my fingers are frozen!” if you traversed the world without gloves or some other kind of hand protection.
But you are still able to move around and hopefully convince your body to move out of the cold into warmer settings.
Wood frogs, the only frogs who hang out north of the Arctic Circle, opt for a different kind of winter celebration. Most frogs hibernate underwater in lakes, ponds, or streams. They’re dormant, but their body temperatures never dip below freezing.
Of course, that knowledge makes it even more confusing that falling in the river was how you lost while playing Frogger. It’s like the creators at Konami didn’t even do their basic amphibian research!
Wood frogs don’t take this tactic.
Instead, they hibernate by finding a nice batch of leaves—namely, “duff,” or leaf litter. As a fan of The Simpsons growing up, I’m intrigued by a reference to “duff” that isn’t Duff Beer or the corresponding Duffman spokesman.
In any case, wood frogs cozy up in the duff and receive some warmth from leaves and any snow in the area. It’s not enough to stop them from freezing. For up to eight months of the year, there’s ice in their organs and abdominal cavity. There’s ice between layers of skin and muscle. Their eye lenses freeze, so their eyes turn white.
While all this is happening, the wood frog’s liver is hard at work producing glucose. Doing so flushes its bodies cells and creates an interesting effect: The cells themselves don’t actually freeze, and the sugar solution connects the water molecules inside the cells so the frog retains some hydration.
That’s the key to survival. There’s ice around the organs and cells, but that ice never enters the cells. So, a wood frog can spend the entire winter without moving (or breathing) at all.
Then, when spring rolls around, the wood frog’s heart starts beating. Then its brain begins again, and is maybe a bit confused about why it can’t move. But those legs thaw out soon enough, and the wood frog gets back on with its normal day.
If you’ve seen The Shining, you know being frozen outside for even a night typically has deadly effects for humans. Yet, wood frogs can, again, SPEND UP TO EIGHT MONTHS OF THE YEAR COMPLETELY FROZEN.
Sorry for the all caps, I couldn’t let it go. #badfrozenjokes
Studying wood frogs could potentially be used to help humans freeze their own organs for medical purposes down the line. Maybe we’re not so far off from reanimated heads, after all!