There is an old log on one of the hiking trails at Algonquin Provincial Park that dates back to 1890 that I used to visit when I was younger. Early loggers had felled a giant White Pine, and after taking off the top and all the limbs, they discovered some defect in the main trunk. Taking the good part, they left the defective section to rot in the woods. Even after more than 135 years, the log still retains its shape, but is slowly on its way to becoming part of the forest floor. Dozens of seedlings, some of them conifers, have taken root atop the moss-covered log, hastening its decay.

An old log is a neat place to find things, for while life appears to be over, life continues on within its rotting mass. A log whose breakdown is well under way is porous and spongy, and readily absorbs moisture from the ground. Even if the log is unable to find this moisture, there is always an internal source of water. The fungi that are present in logs actually produce water as a result of their functioning. Those animals that live in a log require moisture since they lose it rapidly through evaporation from the body surface under dry conditions. This is especially true for millipedes and slugs.

A log represents a sort of controlled atmosphere. This is important since many of the animals that live in a log are unable to control their body temperature. Salamanders and snakes are occasional visitors to logs. In fact, this is most likely where you would find the retiring Little Brown Snake. Some animals live their entire lives in logs – winter as well as summer.

Most of us are familiar with the Pill Bug, Wood Louse or Sow Bug. Look for them in your basement near the sump pump, or wherever it may be damp. You will not see them right away, as they hide under damp boards and other objects.  It is a scavenger common to decaying logs, and is unusual in that it is actually a crustacean. This makes it a close relative to the shrimp, lobster and crab.

But what are they doing away from the usual habitats of shrimps, lobsters and crabs? Well, at some point, these small oval bugs apparently gave up the watery habitat of their close relatives and have succeeded on land. They have not, however, given up their need for moisture. The air around these bugs must be moist in order for the blood running through the gills – and they do have gills, like their relatives – to absorb oxygen. Hence, their fondness for rotting logs as well as damp basements. In the logs, these little pill bugs provide important items in the diets of salamanders, frogs, and spiders.

Millipedes and Centipedes are both arthropods, also related to the crabs and lobsters. Although dubiously blessed with many legs, they don’t have nearly as many as their names suggest. Millipedes may have as many as 50 segments with two pairs of legs per segment, for a grand total of 200 legs.

 Centipedes on the other hand seldom have more than 15 segments, and only one pair of legs per segment, for a total of 30 legs. While Millipedes are largely vegetarian, consuming rotting leaf matter, thus turning organic materials into usable compost, Centipedes are carnivores, feeding on larvae. They lost their sense of sight and smell many years ago and rely entirely on their sensitive antennae.

It is all these little creatures, working harmoniously together, that will one day return this log to the earth, enriching the soil, and benefitting the trees and other vegetation that have located nearby.  For the log at Algonquin Provincial Park, its days are numbered, and in another hundred years, or so, Park staff will have to remove the interpretive sign as there will be nothing to see but a slightly raised knoll of powdery soil.

Terry Sprague lives in Prince Edward County and is a retired professional naturalist. He facilitates a weekly Coffee Chat meeting every Friday morning at Picton’s Community Care for Seniors.

 For more information on nature, check out the NatureStuff website at http://www.naturestuff.net . He can be reached at tsprague@xplornet.com.