Life on a log

by Shane Gibson, Environmental Education Director

This article originally appeared in the summer 2020 issue of The Twig, our member newsletter. To see more articles and past issues, click here.

Not all wildlife encounters are as obvious as a deer crossing the road, a squirrel on a birdfeeder, or a hawk on a roadside fence post. Those animals are large and often in plain sight and utilize large habitats. A deer’s habitat range includes about 650 acres, or roughly one square mile. A squirrel may use a few acres, and a red-tailed hawk’s range is approximately two square miles.

Some wildlife live in much smaller quarters. You might never see them unless you look under a rock, dip in the muck of a pond, or look under the bark of a fallen log. These microhabitats are teeming with life.

In nature education, the foundation for many of Sycamore’s lessons with classrooms and other groups is making observations and using your senses to notice the world around you. Having an awareness of your surroundings and noticing the little things can bring many joys and surprises.

What do you see when you roll a log, peel back the fragile bark, or pull apart the soft, spongy fiber? You might find grubs. Grubs in wood are usually the larvae of beetles. One common species is the patent leather beetle or horned passalus. Both the larvae and adults can be found in rotten wood. The adults feed primarily on decaying wood and fungus while the larvae get their nutrients from predigested wood from the parents. Using its large mandibles, the adult patent leather beetle can carve tunnels and passageways to live and reproduce.

The name “centipede” means a hundred feet. These myriapods,cousins of insects, also seek shelter under a rotting log as well as under rocks, leaf litter, and cracks in a wall. Centipedes find these environments inviting, as they need high humidity or moisture to survive. Like all wildlife, centipedes go where food is plentiful. And for an insectivore like a centipede, a fallen log can provide
plenty of sustenance.

A rotting log can also provide hibernation shelter for insects. A queen bumble bee will burrow in an old log or soft earth or work its way under a rock. This newly mated queen may be the only one from the colony to survive as the old queens, workers, and males will die off. A baldfaced hornet queen will do the same thing. Once they emerge in spring, they begin to build their new nests.

Look closely at a fallen log and you might see several species of ants, roly polys, salamanders, moss, fungus, ferns, and more. A log is a host to many species of decomposers that assist in breaking down organic matter. The dead tree gives new life to the world around it.

When looking under a fallen log or rock, be sure to put it back where you found it. It’s like taking the roof off their house, so putting it back provides the shelter they need.

A fallen log may be able to tell you a story about the area in which it is found. It may also produce more questions than answers. In a notebook, write down your observations and questions that you have. Make a sketch of what you see and the sounds around you.