Frogs and toads are found on every continent, except Antarctica. Over the past 2 million years, these amphibians have adapted to a wide variety of niches all over the world. There are over 2700 species of frogs and toads worldwide, with new species being discovered regularly. In Canada, there are 25 species, and in Ontario there are 13. Ontario frogs and toads live in a variety of habitats including terrestrial (land), aquatic (water) and arboreal (in trees) and they can even be found at the most northern latitude of the province.

The frogs and toads of Ontario are divided into 3 types:

• True Frogs

  • American Bullfrog
  • Green Frog
  • Mink Frog
  • Northern Leopard Frog
  • Northern Cricket Frog
  • Pickerel Frog
  • Wood Frog

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Ontario frogs and toads lay their eggs in water which later hatch into tadpoles in the spring. Some northern species (green, mink and bull frogs) overwinter in tadpole form due to shorter seasons. Tadpoles are vegetarians, but once in their adult form, they will eat insects and sometimes birds, mammals, snakes or other frogs. I’ve even seen one try to eat a caterpillar, but it ended up spitting it out!

Northern Leopard Frog capturing a Woolly Bear caterpillar.

Frog shaking the caterpillar from side to side.

Struggling to swallow the caterpillar…

The frog eventually giving up and spitting the caterpillar out.

To survive the Ontario winters, frogs and toads have developed their own survival techniques. American Toads burrow into the ground and survive under the frost line. Gray Tree Frogs, Spring Peepers, and Wood Frogs all hibernate under piles of leaves, logs or rocks and they increase the amount of glucose in their organs to survive freezing (like antifreeze). Northern Leopard Frogs, Bullfrogs, Green Frogs and Mink Frogs all hibernate in water that is deep enough not to freeze solid.

In Southern Ontario, you can start hearing the calls of male frogs and toads in late March or April / May in Northern Ontario. Spring Peepers, Wood Frogs and Chorus Frogs are usually the first you’ll hear. Bullfrogs may not start calling until late June or July. Each frog species’ call is very distinct and is very useful in identification, especially since you can often hear them but not see them. Check out Nature Watch’s site to see pictures, descriptions and sounds of each of Ontario’s 13 species. You can also help with research and conservation by becoming a Frog Watcher. Dusk is usually the best time to listen for frogs but some species (Green Frogs and Spring Peepers) will call during the day, especially after the rain.

Comparing Frogs & Toads

FROGS

• Hind legs are long and powerful for jumping
• Skin is moist and smooth
• Spend most of their time in the water
• Eyes bulge out
• Have a lot of predators to worry about

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TOADS

• Hind legs are shorter for walking and hopping
• Skin is dry and bumpy
• Spend most of their time on land
• Eyes do not bulge
• Have fewer predators

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Frogs are an indicator species and can tell us a lot about the environmental health of the ecosystem they are living in. Frogs and toads have a semi-permeable skin and live ‘between water and land’ and are therefore easily affected by pollution and other environmental changes.

Factors Affecting & Threatening Amphibians:

[one_third_last]Acid Rain

Agricultural Chemicals

Hormone-mimicking Chemicals[/one_third_last]

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• Toads have no teeth.
• The golden poison frog (also known as the golden dart frog) from South America is the most poisonous vertebrate (animals with an internal skeleton like humans, birds and snakes) in the world
• There are more than 2700 species of frogs and toads in the world. There are 25 species in Canada and 13 in Ontario.
• Frogs do not drink water, they absorb it through their skin.
• Each year a frog hibernates a ring is formed in their bones, just like tree rings.
• Frogs and toads are carnivores (they eat meat).
• The largest frog in the world is the Goliath Frog and it lives in Cameroon and Equatorial New Guinea. The Goliath Frog can weigh over 7 pounds and grow up to 32 cm long.
• The smallest frog in the world is the Paedophryne amauensis. This frog was found in 2012 and is only 7.7 mm long – that’s about as long as a housefly. The frog was discovered in Papua New Guinea.
• Frogs and toads shut their eyes to swallow.

Designed by Karen Brazell. Produced by Kate Fulton.

Sources:

Canadian Amphibian and Reptile Conservation Network. [Accessed 06 May 2015].
“Canadian Herpetological Society.” CARCNET. N.p., n.d. Web. 06 May 2015.
Cook, Francis R. (1984). Introduction to Canadian Amphibians and Reptiles. National Museums of Canada: Ottawa, ON.
Frogs and Toads of Ontario. Adopt-A-Pond, Toronto Zoo. [Accessed 06 May 2015].
FrogWatch Ontario. [Accessed 06 May 2015].
“Frogs and Toads of Ontario.” NCC:. N.p., n.d. Web. 06 May 2015.
“Frog vs Toad.” – Difference and Comparison. N.p., n.d. Web. 06 May 2015.