Post by Jen Berlinghof
Last week, our Wetland Explorers summer nature campers went wild…in a good way! We were hiking along the Des Plaines River Trail when we came upon a major toad hatch-out. Hundreds of dime-sized toadlets took over the trail, prompting shrieks of excitement from the campers. The kids scurried around, scooping up handfuls of toads, trying to save all the hopping and popping amphibians from potentially hazardous bike tires and hiking boots along the trail.
The American toad, Anaxyrus americanus, is a common amphibian in Lake County, Illinois. Like other amphibians, this species of frog leads a “dual life,” spending stages of its life cycle in water and on land. These toads have unique adaptations to help them elude potential predators. The skin of toad tadpoles, as well as adult toads, contain glands that produce toxic fluids which can be harmful to predators that swallow them or get them in their eyes. If grabbed by the beaks of hawks or herons, or by the jaws of raccoons or snakes, adult toads will inflate themselves like a balloon, hoping they can no longer fit down the throat of the predator.
If all else fails, toads will urinate, which typically gets the predator to drop them. But of all these defenses, none is as successful for the species as the strategy of “safety in numbers” we witnessed that morning at summer camp.
While solitary as adults, American toads are known to go through metamorphosis in synchrony, or all at the same time. Thousands of teeny toadlets emerge from a pond within a few days. Less time in the water as an egg or tadpole means less time for a predacious diving beetle, fish or dragonfly nymph to eat you.
Once metamorphosis is complete and toads hit land, they have to contend with different predators. The most troublesome are garter snakes. These snakes are immune to the effects of the toad’s toxic skin and will gather around ponds in early summer, gorging themselves on a toad buffet. Emerging en masse makes it impossible for the snakes to eat all the baby toads, allowing many to survive and hop away on their pudgy legs to grow into adulthood in the woods. Research has shown that tadpoles raised in the presence of predators show higher levels of aggregation than tadpoles raised in their absence.
So perhaps the magic of a toad is not kissing it to transform it into a prince, but rather the wonder and awe of a mass emergence seen through the eyes of an eight-year-old child. Toads will likely be seen in high numbers countywide over the next few weeks. See a little of the magic for yourself along the trails, but watch your step while exploring the preserves! Want to sign your child up for fun and learning with our expert educators? Visit www.LCFPD.org/camps to learn more.