Wood Frog

Lithobates sylvaticus

Amphibian

Transcript:

Today on Animal Fact Files we’re talking about wood frogs. For more facts on other animals, don’t forget to subscribe! Wood frogs were requested by Zrgly Fish; this was an awesome suggestion! Have you ever wondered how Captain America survived for decades frozen in ice? According to Marvel, it has to do with raised glucose levels in his blood, a trick also employed by the star of today’s episode.

Wood frogs are able to withstand more than 50% of their body freezing during harsh winters. This is accomplished via raised glucose levels which acts as an antifreeze in the cells of a wood frog. During this time a wood frog’s heart stops beating, lungs stop breathing, and blood stops flowing, which is nearly universally the signal of death - heck, they’ll even feel hard to the touch just like an ice cube, but, come the end of winter and the start of spring, these little amphibians defy Hades himself and wake up from their frozen slumber. And it’s at this time they’re ready to mate.

Wood frogs tend to hibernate in forests with plenty of cover, but they need water to reproduce. Many will migrate to a more appropriate breeding area with open ponds lacking fish. Male wood frogs, who are usually silent throughout the rest of the year, sound a mating call that’s been described as something akin to ducks quacking, and mating is basically a game of leap first and ask questions later.

A male wood frog will determine if the frog he’s mounted is the frog for him based on its size. Other males, and females who have already laid eggs, are much thinner than the larger females still full of unfertilized eggs. Therefore, girth is a male’s cue to get busy! Females will lay eggs at the bottom of temporary pools formed by thawing ice and leave them forever. The eggs will hatch within a month and the tadpoles will take about two months before they fully metamorphose. It’ll be a few years before they’re ready to have babies of their own, and on average wood frogs will live to be about five years old.

It’s been observed that wood frog tadpoles have strong kinship. In one study, wood frog tadpoles always showed preference to their genetic siblings even if they weren’t raised together. It’s also been suggested, if wood frog tadpoles witness one of their siblings being consumed by salamander larvae, they will learn to be still if they sense the salamander larvae in the future thus making them more difficult to discover.

Wood frogs have also been shown to quickly develop resistance to pesticides used in agriculture. This could be an indicator to farmers that insects may be able to develop this kind of resistance, as well. Plus, wood frogs were used in a study to determine the living conditions of tailings ponds in oil sand mining which concluded that after a period of eight years, the tailings ponds caused no increase in thyroid levels of wood frogs. This could indicate that tailings ponds become less toxic with age. AND, these curious critters are currently in the line-up to become New York’s official state amphibian thanks to a project headed by a young woman with a fascination of frogs. Wood frogs have been a helpful species to us! Be sure to thank one next time you see one.

Usually you can easily identify a wood frog by the mask-like black bars behind their eyes and their bright upper lip. They’re found in northern parts of North America, and they’re the only frog found in the Arctic Circle on this side of the globe. They can be anywhere from 1.5 inches (3.81cm) to more than 3 inches (7.62cm) long. They’re brown, grey, and olive green, sometimes with reddish rear legs. And although they act as a cold remedy in the show Avatar: The Last Airbender - we here at AFF would not recommend licking those frozen frogsicles.

For more facts on wood frogs, check out the links in the description. What do you think of wood frogs? Let us know in the comments! Thank you for watching, and give a thumbs up for more Animal Fact Files!