By Kelly Vowels
Fall is a fantastic time of year at Bernheim Forest and Arboretum. With Halloween just around the corner, it’s the perfect season to be both a little spooked and a lot fascinated by nature. From spiders spinning their webs to bats swooping at dusk, the forest is alive with activity.
Spiders of the Season
Fall is one of the best times to spot spiders at Bernheim. More than 90 species have been documented here, ranging from the comically cute jumping spiders to the deadly black widow. Spiders are often more visible in fall for several reasons.
Many species breed during this season, and males leave their webs in search of mates. They follow chemical cues or silk threads released by females that signal they are ready to mate. In some species, the males take the lead by performing elaborate dances to attract attention.
After mating, many spiders lay their eggs in winter, and the young hatch in spring. By fall, adult spiders have grown larger and are easier to see as they hunt for prey or search for sheltered areas to lay eggs. Great places to look for spiders at Bernheim include rock outcroppings, near buildings, and throughout the forest.
Bats Before Hibernation
Evenings in fall are also a great time to catch one last glimpse of bats before they settle into hibernation. Bernheim is home to at least ten confirmed bat species, with the possibility of three more. Kentucky is home to sixteen bat species in total.
Four of these species migrate and hibernate in leaf litter or beneath tree bark. Bernheim hosts at least three of these migratory species, including the silver-haired bat (Lasionycteris noctivagans). Silver-haired bats are most often seen during fall and spring and are rarely spotted during the summer breeding season in Kentucky.
The other thirteen species found in Kentucky spend the winter in caves. During fall, these bats are busy building up fat reserves to sustain them through the colder months. Like spiders, bats also spend fall mating, though females delay fertilization until spring. They store sperm through the winter before fertilizing their eggs when the weather warms. At dusk, you can often spot bats darting through the air across Bernheim’s skies.
Glowing in the Dark
Fall is also a great time to discover the bioluminescent jack-o’-lantern mushroom (Omphalotus illudens). This bright orange fungus produces luciferase, an enzyme that makes its gills glow faintly in the dark. It typically appears in late summer through fall and can be found growing at the base of trees throughout Bernheim. Despite its beauty, the jack-o’-lantern mushroom is poisonous to humans. It is also known as “foxfire,” a name long used to describe naturally glowing fungi.
Rediscover the Forest
Every season at Bernheim offers something fascinating to see, from the smallest spider to the grandest oak. Fall is a particularly magical time to explore. Come enjoy the colors, creatures, and quiet wonder of nature while the season lasts, and rediscover Bernheim Forest all year long.
