Text by Doug Collicutt

Among the many things that herald spring in Manitoba, one of my favourites is the "quork, quork, quork" of wood frog males calling for mates. When winter's snow is all but gone, leaving ponds and ditches brimming with melt water, wood frogs emerge from hibernation and get right to the business of breeding. Wood frogs (Rana sylvatica) are among the first amphibians to breed each year in Manitoba, starting as early as mid-April in the southern part of the province. They are found throughout the province, so they are a spring harbinger we can all appreciate.

Wood frogs are truly remarkable little creatures. They are the most widely distributed amphibian in North America, even reaching beyond the Arctic circle! They can mature from egg to transformed frog in as little as 45 days (now that's MORPHIN'!). But perhaps their greatest feat is the unique way in which they spend winter, ... frozen solid! Wood frogs are members of a rather exclusive club of vertebrate (back-boned) animals that overwinter on dry land and survive the freezing of their body tissues. World-wide there are only a few species of vertebrates that can tolerate freezing. (Baby painted turtles are the "highest" vertebrates known that can tolerate tissue freezing - yet another story to be told!) Though this feat is "no big deal" to many plants and invertebrates (lots of insects do it), it is a neat trick that enables wood frogs to inhabit many northern environments and frees them from dependence on permanent bodies of water.

Want a little more information on wood frogs? Would you like to experience raising wood frogs yourself, maybe even in your classroom? Then read on!

Wood frogs can be raised from egg to small froglets in less than 50 days. All that is required is a container with clean, oxygenated water and simple foods, such as boiled lettuce or fish food (commercial flakes). Check out: Wood Frogs in the Class Room and Frog Log

Click the right arrow for more on wood frogs

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