Thursday, December 1, 2016

Native Species Profile - American Toad

Michigan is home to twenty-three species of amphibians (ten salamanders and thirteen toads/frogs).  Some species are extremely rare, others can be found throughout the state.  One of the most common species is the American Toad (Anaxyrus americanus).  Not only is the American Toad common in Michigan, it is common across the eastern United States and Canada.  It ranges from the Atlantic Coast west to a line running from Manitoba through the eastern edge of the Dakotas south to northeast Texas.  It is found as far north as Hudson Bay and as far south as northern Mississippi, Alabama, and Georgia.

American Toad in a lawn

The American Toad has such a broad range because unlike most amphibian it often ranges far from water.  The American Toad does need water for breeding, but during the rest of the year it is found in a variety of habitats ranging from woodlands to prairies, lawns, and fields.  In the winter it hibernates below ground.

Male American Toads calling for mates - note the inflated throats

The American Toad is generally colored in shades of brown or tan, although red or green individuals are sometimes found.  Their bodies are covered with a variety of bumps or "warts" - the largest warts are located behind the eyes.  These are actually a pair of glands (parotid glands) that secrete a toxic liquid if the toad is attacked.  This poison ensures that very few animals will eat toads.  The Eastern Hognose Snake does not seem to be affected by the venom and common preys on toads.  I have also seen an American Robin eating tiny toads just as they emerged from a pond after metamorphosis.

American Toad - note squat body, short legs, and numerous warts

The American Toad generally reaches a length of 2 to 4 inches as an adult.  Unlike frogs, it is a weak hopper with (relatively) short hind legs and a stout body.  When traveling short distances it often walks instead of hopping.

As an adult, the American Toad is a carnivore.  It eats a diet consisting of insects, spiders, worms, slugs, and other invertebrates.  The small black toad tadpoles are herbivores; they scrape algae from the surface of plants and other objects in the water.

American Toad eggs are deposited in strings and covered with a thick mucous to deter predators

This species was recently reclassified based on genetic information.  It was formerly known by the scientific name Bufo americanus.  Most field guides and other books will list the species under this old name.

Basic Information

American Toad
Anaxyrus americanus (formerly known as Bufo americanus)

Size:  2-4" long

Habitat:  woodlands, prairies, wetlands, lawns, fields

Eats:  insects, worms, spiders, slugs

No comments:

Post a Comment