Amphibians

How many kids aren’t thrilled at the sight of a frog? Even in the North, amphibians intrigue and inspire both children and adults. The Yukon Amphibians (pdf, 1 Mb) booklet will help you view and identify all five species of amphibians known to the Yukon and northern British Columbia. It also includes information on how you can contribute to science and conservation by reporting your sightings.

Cold-blooded in a cold climate

Frogs, toads and salamanders are cold-blooded. Unlike humans, they cannot generate enough of their own heat to stay warm. In the North, gaining warmth from the environment isn’t easy! The Yukon’s extremely cold winters, short cool summers, scarce hibernation sites and lack of snow cover for insulation have kept amphibians away.

Northern amphibians survive the winter by hibernating underground, under ponds or under leaf litter beneath a blanket of snow. While most amphibians freeze to death if cooled below minus 1 or 2° C, wood frogs and boreal Chorus frogs can survive temperatures as low as -12° C. They produce glucose in the liver, which acts as antifreeze and prevents the cells from bursting. The heart stops beating, the fluid between the cells freezes, and the frogs look frozen solid. Yet they emerge, safe and sound, in spring.

Frogs, toads and salamanders take full advantage of the warmth of spring and summer. Their eggs are large and dark to absorb heat, and are submerged in warmer shallow water, below the surface, which might freeze. Tadpoles bask in the sun in the shallows, while adult frogs and toads bask on land or in shallow water in the heat of the day. Some amphibians that are nocturnal in warmer climates prefer the brightest part of the day in the North.