The Hills Are Alive…With Snails? by Mike O’Brien

Updated: Apr 29

The remnant prairies that we have in the La Crosse area, and the Driftless Area in general, are blessed with a wide variety of native flowers, grasses, birds and insects. But one type of animal that usually doesn’t come to mind are snails. Amazingly there is a wide variety of terrestrial gastropods (land snails) in the hill prairies of western Wisconsin including ours in the La Crosse Blufflands. One survey from several hill prairie sites in the Driftless Area recorded at least 29 different species (out of 100 in Wisconsin) including one, Gastrocopta procera, that is listed as Threatened in Wisconsin. But the snails we speak of are very small. Most or all are smaller than fingernail size and fit comfortably on a blade of grass. If you have ever kicked up some dirt on a hill prairie during one of our work outings you have probably encountered at least the shell of a snail whether you knew it or not.

Land snails are in the phylum Mollusca, and in the Class Gastropoda which is Latin for stomach foot. This foot is the muscular portion below its abdomen that propels the snail by waves of contractions. It also has tiny hairs called cilia that also perform this action. Add some slimy mucous and it can go over just about anything. The snails on our prairies represent small population remnants from prairies that once were much more common in drier periods thousands of years ago. They like the calcium rich environment these hill prairies provide and eat mainly plants and decaying matter with their sharp tongue.

As mentioned above, the tiny snail called Gastrocopta procera or Wing Snaggletooth is a species that in Wisconsin can only be found in the Driftless Area and here only in the hill or “goat prairies” such as those we are restoring in the La Crosse Blufflands tracts and Hixon Forest. It is found elsewhere in the country but it is holding out here due to the dry, warmer habitat it can find on the hill prairies. Thousands of years ago much of Wisconsin and the surrounding area had a drier climate conducive to prairie and this snail was likely more widespread at that time.

It is fairly easy to find these tiny snail shells in the dirt of the prairie but please don’t disturb our prairie soil just for this. To find a live snail sometimes it is worthwhile to look on the upslope side of a detached boulder down in the grass and debris. So next time you’re out take a closer inspection of the dirt beneath your feet – you might be amazed to discover what’s alive down there!

Terrestrial snail shell found on Zoerb Prairie, Hixon Forest.

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