From our Naturalist, Rosetta
When the sun sets and Flat Rock Brook’s visitors have gone home, the trails are not abandoned. That’s the time when our nocturnal residents come out of their sleeping chambers and the nature preserve belongs to them. Some creatures of the night have been seen flying overhead or moving along the trails at dusk or at night. If you have gone on a guided night hike, you may have been lucky enough to spot some of them. We have been able to verify the existence of several species whose images have been captured by motion-sensitive cameras that are placed at strategic points along our trails.
Although we see an occasional fox, opossum, or skunk during the day or early evening, these species are most active at night, as evidenced by our cameras. They have also captured photos of raccoons, coyotes, cottontail rabbits, and flying squirrels. Bats do not appear in the camera shots but they are seen flying over Quarry Pond in the evening hours, and at times over surrounding homes and yards as they hunt for flying insects. Porcupines and other nocturnal animals have left evidence of their presence in signs such as scat, tracks, and marks on tree trunks. Great horned owls and Eastern screech owls have nested in our forest in past years, and occasionally visit in passing.
The red fox and coyote are both adaptable animals that do very well in suburban areas. Both are more active at night but can be seen at any time of day. Coyotes are a more recent inhabitant of FRB and of the eastern USA, in general. Although our cameras have captured them, a coyote’s senses of smell, hearing and alertness are especially keen. Its natural instinct is to steer clear of people. For this reason it is unlikely that you will cross paths with one.
We are all familiar with the eastern gray squirrels, especially those of you who have bird feeders. Did you know that southern flying squirrels (Glaucomys volans) are present in FRB? They are not capable of true flight but have evolved several features enabling them to glide and forage at night. Flying squirrels are small, have a flap of skin between the front and rear legs and a flattened tail, which acts like a sail and enables them to extend jumps into glides. Their large eyes help them see at night. Although we haven’t seen them directly, our cameras have shown them clinging to the trunks of trees.
Another nocturnal animal that we have not seen, but have inferred they live among us are porcupines, because they have left signs of their presence. Porcupines feed on the bark of woody plants in winter, gnawing only deep enough on a tree trunk or branch to feed on the nutritious bark, stripping it down to the bare wood. Look for signs of browsing on the trees as you hike along our trails.
You’ll note in some of our photos that many of our night visitors' eyes appear to glow in the dark. That is not due to the use of a flash, which our cameras do not have, but it is a reflective layer behind the retina called the tapetum lucidum, which means “light tapestry”. The purpose of the tapetum lucidum, which is mostly found in nocturnal mammals, is to improve night vision. When light enters the eye, but does not hit a photoreceptor (rods and cones) in the retina, it hits the tapetum lucidum and reflects as if from a mirror to bounce back for a second chance to hit the photoreceptors.
If you haven’t had the opportunity to see any nocturnal residents or visitors at Flat Rock Brook, the best chance you can have is to join our naturalists or trail guides on a night hike once we are able to resume them. We hope we will be able to see you some time this year!
