As mother nature slowly begins to tease us with the occasional warm day, and longer periods of sunlight, I can’t help but dream of warmer days spent exploring outside, underneath the forest canopy. One of my favorite things to do while exploring the forest is to take in the intricacies of the forest floor, and discover the diverse life that inhabits that space. Between the litter layer, growing mosses, and decaying logs, a utopia full of life is waiting to be unearthed.
One of my best memories exploring the forests of the Northwoods comes from the forest floor. My boots sunk into the damp litter layer next to a large tree, dotted with mushrooms and carpeted in moss. As I knelt down on the soggy ground to get a better look at the mushrooms growing from the trunk of the tree, a movement among the mushrooms caught my eye. Slowly making their way across the cap of one mushroom, was a slug! I watched as they made their way over to the stalk of another mushroom, their eye stalks extended and moving. Upon a closer look, I realized that this slug had been snacking on the mushrooms! The gills and caps of numerous mushrooms had pieces missing from them, and this slug seemed to still be feeling snacky.
Once I had spotted one slug nibbling away at a mushroom, I began to find many more mushroom-snacking slugs around the base of the tree. A cluster of honey mushrooms had three hungry slugs, all chomping away at the mushrooms gills and cap. To eat these mushrooms, the slugs were using their radula, a tongue-like structure that is covered in thousands of microscopic teeth called denticles. With each “bite” they are using their radula to sand off tiny portions of mushroom to eat. Shiny trails of slime were strung about the mushrooms, giving hints to where the slugs had previously been. The mucus produced by slugs both acts like a sticky glue, holding them to the surface they are moving across, and aids in their movement. When the slug is moving, the mucus becomes fluid-like, helping them to glide across the surface of whatever they are on. But once they stop, that mucus becomes more glue-like, cementing them to the surface. One slug was using their sticky mucus to cling to the vertically angled cap of a honey mushroom as they munched away.
Slugs are important decomposers within a forest ecosystem. They eat decaying plant material, breaking it down, and contributing those nutrients back into the soil. But while eating mushrooms, they are doing more than facilitating the breakdown of nutrients back into the soil. Recent studies have found that slugs are helping in the dispersal of mushroom spores. Through crawling all over the mushrooms, and snacking on the spore producing parts of a mushroom, they have been found to be transporting those spores both internally, and externally. These slugs then crawl all around the forest floor, traveling through the leaf litter, along decaying logs, exposed soil and plant roots, and on tree bark. This leads to potentially spreading fungi spores to new places they could establish, further contributing to forest decomposition and nutrient recycling. That's quite the contribution to forest health, coming from such a small creature.
And even though winter still has the Northwoods within its grasp, I am looking forward to the warmer days where the forest floor is bursting with life, and slugs are once again found gnawing on mushrooms.
For more than 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Our Summer Calendar is open for registration! Visit our new exhibit, “Becoming the Northwoods: Akiing (A Special Place). Follow us on Facebook, Instagram, YouTube, and cablemuseum.org to see what we are up to.
