Bryan Ludvik

Science & Nature

Frogs And Toads

By Bryan Ludvik

In preparation for a fourth grade science class, our teacher blundered by sending myself and friend Charlie Krum down to a nearby pond to try to catch frog specimens. Of course we dawdled! Eventually, the principal came along to usher us back to school.

We were sternly reprimanded, but I didn't regret it; that was an incident that helped spark my interest in science and nature.

Charlie and I noticed that there were only tadpoles in the pond. It was too early in the season for them to grow up to be adult frogs. Our teacher should have known that.

Later, as I was sitting in detention during playtime, a girl came in screaming, bent over backwards. A schoolyard bully had dropped a toad down the back of her dress. She recovered from the trauma but, to this day, her nickname remains Toad.

What's the difference between frogs and toads? They're not really that closely related, other than being amphibians. Frogs are wet, and toads are dry, even though they're both born in water.

Adult toads migrate to higher ground and burrow. They have a tough dry skin that helps them retain water. Frogs don't have to worry about that; they spend most of their time splashing in water.

I ran across the term, "convergent evolution," whereby diff erent species develop similar traits. I liken it to cats and dogs.

They both have four legs and a tail, wet noses, and they oft en snuggle up to humans, even though they're obviously very diff erent critters.

Of notable concern is a global decline in amphibian populations, and malformed frogs, first reported in Minnesota in the 1990s. Frogs and toads can be sensitive indicators of a changing environment.

To address that issue, the Department of Natural Resources has initiated a program of frog and toad counting in several areas.

Trained volunteers regularly scout selected sites. In darkness, they count by listening for the songs of various species at specifi c locations. That information will be compiled and analyzed by experts in the field.

For more information, visit the Minnesota Frog & Toad Calling Survey (MFTCS) Web site at http://www.dnr.state.mn.us/volunteering/frogtoad_survey/index.html, call Krista Larson at 651-259-5120 or e-mail krista.larson@dnr.state.mn.us.