Logo bar of the Alaska Public Lands Information Centers which are located in Anchorage, Fairbanks, Tok and Ketchikan
A downed tree rests across a forested stream. Ferns and moss cover the tree and everything else in sight. This is the Tongass National Forest - a rain forest in Alaska.
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Alaska's Frog

Listen to this podcast on Alaska's amazing frog! Download Quicktime if needed or a MP3 version. Or just read along below.

Little brown wood frog sits on a leaf.
Transcript: (Sound of wood frog call) Wouldn’t it be amazing if a human could turn to ice in the winter, and then thaw out one spring day? Well, that’s exactly what a wood frog does. Every year.
The common wood frog, Rana sylvatica, is just a little guy, less than 3 inches long. It can be identified by dark, mask-like markings across it’s eyes, a dark green to brown coloring, and a lighter underbelly. The wood frog’s range is from southern Ohio, across Canada, and all the way to northern Alaska. It’s the only frog in the world that’s found north of the arctic circle. In climates that cold, warm-blooded animals have to migrate or den up to preserve their body heat, but cold-blooded animals must find different ways to survive. Fish, for example, will go dormant at the bottoms of lakes, where the water is still liquid. Some arctic fish and insects survive by building up high levels of blood sugars or antifreeze proteins, to lower the freezing temperature of the water in their bodies. If any of them were to freeze solid, the ice crystals would wreak havoc! They can severely damage organs, mangle cells, and split through blood vessels. Water is drawn from nearby cells as an ice crystal grows, leaving the cells shrunken and destroyed. But the common wood frog has an amazing ability to control how it freezes. At the first snow, it begins pumping water out of it’s cells into spaces where it won’t damage cells if it freezes. At the same time, the frog pumps large amounts of glucose, a sugar created in the liver, into it’s cells. The glucose acts as an antifreeze, protecting the cells. When it finally gets cold enough, it freezes, and flat ice crystals form between layers of tissue and in the body cavity in between organs. Then the blood and organs literally freeze solid! The heart and liver are the last to freeze. By then, 70% of the frog’s body water is ice, and glucose holds the cells together. Breathing stops. The heart stops beating! The eyes turn white because the lens freezes. The frog is basically dead. Except in the spring, it comes to life.
Scientists still have no idea how it does it, but somehow, this frog thaws it’s heart and liver first, and within hours has enough mobility to find a pond and mate. The eggs morph into adults in as little as 45 days, so they can survive freezing through the next winter. Luckily, these incredible little frogs aren’t endangered or threatened. But amphibians as a group are in big trouble. A fungal disease called chytridiomycosis currently threatens one third of the world’s amphibian species with extinction. Additionally, pesticides, habitat destruction, unsustainable water use, and rising temperatures are causing mutations and death in frog populations.
But You can do a lot to help. Frogs need water, so the less water you waste, the more there is in the frog’s environment. You can save water by turning off the tap when you brush your teeth, drinking tap water instead of bottled, and buying local food. Buying bottled water actually takes more water to make than there is in the bottle, and tap water is really cheap! A straightforward way to help save frogs is don’t eat frog legs! They come from frogs. Also, if you have a garden or a farm, don’t use pesticides, and don’t pollute. (Fade into sound of wood frog's chuckling call)
My name is Christin Anderson and this podcast has been about Alaska’s wood frogs. Don’t forget, April 28th is save the frogs day! Thanks for listening. Have a nice day!

Wood frog dwarfed in a person's palm
This wood frog is barely the size of a finger tip.
The wood frog is a small, ground-dwelling frog, with females usually larger than males. It's call is a chucking, "quock-quock-quock." The wood frog's most distinguishing features are it's black, mask-like eye markings. Wood frogs are active from late April to the end of May. You can participate as a Citizen Scientist by helping find where and in what habitat these frogs live. Visit the Alaska Wood Frog Monitoring Project for more information.

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The wood frog can be found throughout Alaska. It's claim to fame is the amazing ability to freeze solid in the winter, then thaw to life in the spring. Alaska has only six native amphibian species: three species of salamander, one toad, and two species of frogs. The wood frog is the most widely distributed amphibian in Alaska and the only one in the world found north of the Arctic Circle.

There are many threats to frogs, from habitat loss to infectious diseases to poisoning from herbicides. The National Park Service is an organization committed to protecting wilderness, including the habitat of frogs! They are always looking for employees and volunteers to do research, monitoring, or conservation work with wildlife throughout the country.

Click here for Park Service job information

For more information check out these links:

Alaska Amphibians and Reptiles 

Fish and Game: Amphibians and Reptiles

The South face of the sharply pointed Mount St Elias is covered in snow. Did You Know?
Mount Saint Elias in Wrangell-St Elias National Park & Preserve is located only 10 miles from the head of Icy Bay and stands at 18,008 feet. Due to the proximity to ocean waters, it has the highest coastal vertical relief of any mountain in the world.