Amphibians of Canada
Canada has a total of 49 amphibian species - 2 newt, 1
mudpuppy, 20 salamander, 18 frog and 7 toad species - found in all provinces and
territories.
Most of these animals are found in the southern
portion of the country, but one tiny frog - the Wood Frog - can be found as far north as the Northwest
Territories, Nunavut and The Yukon.
In a country where much of the fresh water freezes
solid thoughout the winter months, our amphibians are masters of survival.
Hiding Below The Ground
Many species use abandoned animal burrows, or self dug
burrows, to escape the freezing winter conditions or long summer droughts.
Temperatures in the ground below frost level are wam
enough for them to survive the winter, and cool enough for them to withstand scorching summer temperatures and hot,
dry periods.
Aquatic amphibians may spend the winter in water that
is too deep or fast flowing to freeze solid. There is enough oxygen beneath the ice to keep them alive. Tadpoles
and salamander larvae may spend the winter buried in the mud at the pond bottom.
Freezing & Thawing
Some frogs are freeze tolerant, and survive temperatures as low as -6C. Their body
increases specialized protein and glucose to protect the cells from freezing and drying. Ice crystals form beneath
the skin and through the muscles. Up to 60% of body fluids freeze, circulation stops and the heart stops pumping.
In spring they thaw and resume life.
Strength in Numbers
For many salamander species, communal nesting sites are the answer. Multiple
femailes will lay their eggs in a partiocularly choice site, rather than use a less desireable one on their own.
This improves the chance of a successful hatching, and is common in areas where good nesting sights are
scarce.
Darker is Better
Dark colours absorb heat from the sun more readily than lighter ones. Larvae of
most amphibians are dark green, brownish or black. They often swarm together, increasing the size of the mass to
absorb more heat. Eggs are also laid in large masses so the small dark embryos can attract more heat. The thick
jelly holding the eggs together acts as an insulator against the cold.
Read more about Canada's
amphibians:
Amphibians of British Columbia
Amphibians of the prairies - AB, SK,
MB
Amphibians of Ontario &
Quebec
Amphibians of Labrador
& Newfoundland
Amphibians of the
Maritimes
Amphibians of the Yukon, NWT,
Nunavut
See the Canadian Reptile & Amphibian
Conservation Network for more information
Mudpuppy picture courtesy CARCNET
Information taken from the book Canadian Skin & Scales, written by Pat
Bumstead
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