Walker Nature Center
BRANCHING OUT
A LOOK INSIDE • Calendar 4 • Kids’ Corner 6 • Seed Collection 7 • Halloween 8
Nature Notes Leave the Leaves SEPTEMBER By Pam Findley
By Susan Sims
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Autumn arrives with cool, windy days, bringing the knowledge that winter is around the corner, and nature will begin to transition to a time of dormancy. Hues of red, orange and yellow bathe our forests, gardens and yards as deciduous trees lose their leaves. Yet, some important things are about to happen right below our feet, beginning with the rich, leafy confetti that marks this time of year.
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Hummingbirds migrate to Central America. Pokeberry fruits are ripe. Baby box turtles are hatching. Goldenrods are in bloom. Autumnal equinox is September 22 – Fall begins.
OCTOBER • • • • •
Songbird migration peaks. Tree nuts are ripe. Chipmunks take to their dens. Fragrant Asters have purple blooms. October 29 – Venus at highest point in western sky.
NOVEMBER • • • • •
Deer rut peaks. Dogwood trees have red leaves. First Dark-eyed Juncos arrive from the north. Holly berries are red. November 19 – Partial lunar eclipse.
Sadly, fallen leaves are frequently treated as something to remove and throw away. The fact is, these leaves provide much needed resources that help habitat, improve soils and ultimately benefit the interconnected community we call home.
Help Create Healthy Habitat
Fallen leaves sustain many different species during the fall and throughout the winter, including amphibians, insects, small mammals and arachnids. They supply much needed insulation and food. Many moths and butterflies have a long, hard residency as they overwinter beneath the leaves in our yards and parks. For example, Reston’s nocturnal Luna moth (Actias luna) will spend the entire season snuggled up in a cocoon beneath the leaves, not hatching until spring. Entomologist Doug Tallamy estimates that 94% of moths drop off trees as larvae and cocoon beneath the leaves, bark and soil, waiting to emerge in the spring. That’s a lot of moths that depend on leaves! Many of their butterfly cousins also overwinter as caterpillars or pupae beneath the leaves. These insects create a biological “antifreeze,” and the extra leaves provide a cozy habitat. In Reston, checkerspot and fritillary butterflies rely on decaying leaves to survive. Leaving leaves is essential for these less common species. The threatened American bumblebee (Bombus pensylvanicus) gains great benefit from leaf cover as well. A mated female bumblebee will dig into the ground a few inches beneath soil and leaves to stay protected until she can lay her eggs come spring. She is the only one left to create a new colony. Without proper habitat, she may not survive to establish a new generation of busy pollinators.
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