There is an unseen world of animal life and animal activity most of which happens at night or in the early morning hours when very few people are awake. Most mammals are active at night. Squirrels and chipmunks are exceptions to that general rule. The animals that we rarely see because they only come out at night do leave signs of their activity when they defecate or urinate or leave a scent mark, or when they leave their tracks in the snow or in the mud. Some animals can also be detected by the way in which they eat plants or the bark of trees.
The art of tracking is fascinating for anyone who has spent time exploring it. It’s an especially interesting thing to study in the winter when any animal that walks across the snow will leave an impression behind, even a tiny mouse if the snow is soft enough. Through tracks you can actually piece together a lot of information. With a good track, you can identify which direction the animal was travelling and how fast it was travelling. When a mammal like a fox runs, there will be more and more gaps between the set of tracks as the animal bounds, the faster it goes the greater the distance between the sets of tracks.
In the winter time we regularly find the tracks of Red Fox, Coyote and Eastern Cottontail on the campus along with of course Gray Squirrel. Even Red Fox leave their scent on scent marking posts like rocks or tree stumps. (The rock in this photo was used as a place for a red fox to mark its territory.) The smell, once you learn it, is unmistakeable, it smells somewhat like skunk but less strong.
The little round pellets of excrement that Eastern Cottontail rabbits leave behind are also unmistakeable. This is another way that biologists can detect if the species is present.
Beavers are even coming to the shores of our campus to cut down trees to eat, prompting the campus care employees to place wire mesh around the base of the larger trees. A tree gnawed by a beaver is easily identified and one can tell if it is relatively new or older because the wood will dry and fade in colour as it ages.
Some woodpeckers like the large Pileated Woodpecker that are present on our campus leave very characteristic large rectangular holes in trees when they hunt for carpenter ants in the tree.
But there are other unseen worlds as well, for example in the soil there are thousands of organisms, if not millions, living out their life cycles. And in the waters just below the campus in Lake St. Louis underneath the gentle waves are the unseen aquatic creatures which include giant fish like the Lake Sturgeon and the Muskellunge or very large turtles like the Snapping Turtle, or aquatic insects that exist in the water until they emerge in the warmer time of the year to mate. There is even the unseen world of insects that fly above us at an altitude that insect eating birds like Chimney Swifts fly at in order to capture them.
One creature that emerges in July, can spend up to three to seven years undetected in the soil as a nymph. That creature is a Dog Day Cicada and here is a photograph of one on our campus taken a few years ago. It makes one of the loudest sounds in nature. They are a large insect but they are harmless, and they are a delightful food item for many other animals. Raccoons, wasps and other insects feast on the cicada all season long. Adult cicadas are not known to eat. Instead, they focus their energy on reproducing during their short adult lifespan. They breed, the females lay eggs on branches in trees, and then they die. Larvae hatch from the eggs and fall to the ground, burrowing down into the earth to mature.
After a few years the young nymphs will molt (shed) their exoskeleton, leaving it to dry out in place. These dried-out, crunchy brown ‘shells’ of the younger nymph look just like a living cicada, and it’s not uncommon to see them clutching onto tree trunks, on plant stems, soffits, gutters, window screens, and even blades of tall grass. This is another sign left behind that gives us a clue to their whereabouts.
One of the animals that also comes out at night are American Toads. They keep themselves hidden under logs, dead leaves, or in small burrows in the ground in the day and when it’s night (especially when it’s hot and humid) they come out to eat insects, regularly consuming up to 100 insects in one night.
Even though they have toxic glands on their heads, raccoons avoid this by simply turning the toads on their backs and eating their bellies.
