Walker Nature Center
A LOOK INSIDE • Get Nuts for Clean Water 2 • Kids’ Corner 6 • Compost Your Food Waste 7
BRANCHING OUT
Nature Notes Mighty Oaks, Mighty Food SEPTEMBER By Sharon Gurtz
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Eastern Red-backed Salamanders lay eggs. Young Red Fox begin dispersing. Asters and Goldenrods bloom. Monarch butterflies are migrating.
OCTOBER • • • •
Songbird migration peaks. Snakes seek winter dens. Chipmunks and squirrels gather nuts for winter. Mushrooms are plentiful.
NOVEMBER • • • •
Slugs and snails go into deep sleep. Migratory waterfowl begin to appear. Deer rut peaks. American Holly berries are red.
By Ken Rosenthal
White Oaks are a common tree found in Reston. Stately, large and visually pleasing, their acorns are also an important food for wildlife. Besides squirrels and chipmunks, mammals that eat white oaks include other rodents, deer, fox and bear. Many birds enjoy acorns as well, such as jays, woodpeckers, nuthatches, turkey, thrushes, pheasants, pigeons and even Wood Ducks. There are also numerous species of moths and weevils that specialize in consuming White Oak acorns.
Species like squirrels and jays cache acorns in the soil. This storage benefits them nutritionally as percolation of groundwater through the acorns can leech some of the tannins but they shouldn’t wait too long. Acorns can germinate as soon as they touch soil, even while sitting on the surface. Acorns take root in the fall, growing a shoot with leaves the following spring. By placing the acorns into the soil, squirrels and woodpeckers give the acorns a head start in their growth, and aid in their dispersal.
White oak or red oak? Acorns contain tannins, which produce a bitter taste. Tannins interfere with the ability to metabolize proteins, and in some species, including humans, may cause significant health effects. In preparing acorns for cooking, tannins are removed by rinsing them repeatedly until the water no longer turns brown. Animals prefer the acorns of white oaks because they have fewer tannins than other types of acorns.
Feast or famine Most years, acorns can be difficult to find. Animals that eat acorns readily gobble up any that they spot. When the crop is small, few acorns are left to germinate. In these years, the trees are spending more energy growing than producing acorns. Every three to five years, however, the trees spend more energy producing acorns. This is called a mast year. Continued on page 2
Fall 15 Volume Seventeen