St. Lawrence Islands National Park of Canada

Natural Wonders & Cultural Treasures

It isn’t easy being blue

The Blue Frog © Parks Canada

The green frog (Rana calmitans) population at Mallorytown Landing has some unusual genes—some of the frogs are actually BLUE in colour!

Take a walk on the Mallorytown Landing trails and keep your eyes peeled for a blue frog near the pond.

Green frog skin normally contains two pigments, yellow and black.  The normal green colour of the green frog is caused by a combination of the yellow pigment and structural blue (the structure of certain cells selectively reflects blue light).

If all structural blue and pigment cells were missing, the frog would be albino.  In the case of our blue frogs, however, it’s just xanthin, the yellow pigment, that’s missing (officially, that means the frogs are axanthic).  Take away the yellow pigment, and you’re left with blue!

We’ve spotted completely blue and partially blue frogs in the pond (they really stand out against the green and brown of the surrounding environment).  Stay on the trails and see how many BLUE green frogs you can spot!