Thursday, June 02, 2016

Cultivating an appreciation for toads in Illinois

Cultivating an appreciation for toads in Illinois

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Two species of toads inhabit Illinois, and neither one of them is threatened or endangered. It seems the factors that are contributing to the decline of other amphibians in the state and around the world—habitat loss, fungal infection, chemical contamination, etc.—pose no insurmountable obstacles to the continued health of toad populations here.

So, why give toads a second thought? They are common and approachable. [Pictured is a Fowler's toad I came across on a gravel bar along the Middle Fork of the Vermilion River.] For me, encounters with such creatures hold their own pleasures, and they reinforce the natural inclination to value other forms of life, even animals I’ll probably never see for myself.

At a glance, most people would not notice a difference between adult American toads and Fowler’s toads. Both are about two to three inches long, and they are similarly marked. Their skin is a light shade of gray or brown, dotted with darker spots. One way to distinguish between the two toad species found in Illinois is to observe the number of warts per dark spot on the back: the dark spots on American toads contain only one or two large warts, while the dark spots on Fowler’s toads have three or more smaller warts.

Toads have thicker skin than frogs, which enables them to inhabit drier environments. They thrive in forests, prairies, and wetlands, along the margins of lakes and streams, and even at the edges of highways. Toads can live in the midst agricultural fields and in urban settings, too, as long as they have access to bodies of water for reproduction.

Even when it comes to the choice of where to breed, toads are not very discriminating. If the nearby body of water is a pristine vernal pool, toads will get together there. If it’s a ditch or a flooded field, toads will use that as well (although toad offspring will survive only if the water persists for at least the 40 days it takes them to develop from tadpoles into terrestrial creatures). My family once received a gift of toad tadpoles from the water that had collected on top of a friend’s swimming pool cover.

You might well recognize the mating call of American toads even if you don’t realize you have heard it before. It is a sustained, high pitched trill that carries a very long way. Near ponds and other places where they breed, it is the background sound of evening in April and May.

Do I need to say people don’t get warts from handling toads? People don’t get warts from handling toads.

Under extreme stress toads secrete a toxin from the oblong glands behind their eyes, which irritates the mucous membranes of other animals that would eat them. (For this reason it’s a good idea to wash your hands thoroughly after handling a toad.) This defense works well in many cases, as you know if you’ve ever seen the reaction of a dog that picked up a toad in its mouth, but not all. Some snakes are not bothered by the toxins toads release, and other animals, including skunks and raccoons, get around the problem by eating them from the underside.

If you’re interested in a wildlife experience close to home this summer, you might start by looking for toads in nearby window wells, since they have a knack for falling into them. You can then increase the odds of survival for toads you find in window wells by releasing them a little ways off.