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Fowler's Toad (Bufo fowleri)

Vocalisation

Frogs and toads can be identified visually or by their calls. Did you know that frogs were the first animals on Earth to develop vocal cords and that each frog and toad species the world over has their own unique call! So, like bird calls, frog calls are great identification tools! While both male and female frogs and toads have vocal cords, the vocal cords are more developed in males than females. In addition, only males possess the vocal sacs to amplify the call. So, it can be said that only male frogs call although females may grunt if in they find themselves in extreme danger (like in the jaws of a snake).

Males call for three primary reasons: to attract a mate (breeding call), defend territory, or to warn other frogs of danger! Frog species breed at different times during the spring and summer months and it is at those times that the breeding calls from frogs and toads can be heard (see chart below). Some frogs possess 'rain calls' and call during large rain events outside of their breeding season, such as the Gray Treefrog and the Spring Peeper.

Frog/Toad	Approximate season
Wood Frog	Early spring
Spring Peeper	Early spring
Chorus Frog (Boreal & Midland)	Early spring
American Toad	Spring
Leopard Frog	Spring
Fowler's Toad	Spring
Pickerel Frog	Late spring
Gray Treefrog	Late spring-early summer
Mink Frog	Early summer
Green Frog	Summer
Bullfrog	Late summer
Northern Cricket Frog

To learn to identify Ontario's frog and toad species by sight and sound click here.

POLAR FROGS

The Wood frog is the most widely distributed amphibian in North America; its range even extends into the Arctic Circle!

Freezing Frogs?
Wood frogs spend the winter FROZEN with 65% of the water in their body becoming ice! Canadian researchers have discovered that the Wood frog's breathing and heartbeat, actually STOP as winter approaches. Wood frogs freeze from the inside OUT because if they were to freeze from the outside IN, the pressure from the outside would crush their internal organs. The ability to freeze is possible due to high concentrations of glucose (or sugars), which prevent cells from completely freezing. Specialized proteins in the Wood frog's blood allows them to control the rate at which they freeze and prevents their blood from clotting. Wood frogs are still susceptible to freezing involuntarily. They lose their freeze tolerance shortly after they emerge from hibernation in the spring because their glucose levels and specialised protein levels (which enable them to freeze) are very low. The production of the glucose and proteins are triggered by seasonal phenomena so that once winter arrives, again, the Wood frog will be able to freeze.

Frosty Breeders
Wood frogs hibernate under leaf littler and moss. Because they hibernate near the surface, they are among the first amphibians in North America to emerge from hibernation. They immediately move into ephemeral (vernal) wetlands to breed. Their enthusiastic duck-like quacking call lasts for a few nights in very early spring when breeding takes place. The eggs are attached to emergent vegetation and are laid so early that they are often surrounded by ice on cold spring nights!
The eggs hatch within 1-2 weeks and become adults within two months.

Turtle Island Conservation