Post by Jen Berlinghof
With Halloween fast approaching, much attention is given to animals that are considered “scary.” Foreboding ravens, ominous bats, super-sized spiders and snakes are everywhere. Thankfully, many people know the benefits of these critters. However, it seems there is one thing found in nature, surprisingly flora not fauna, that remains misunderstood and maligned: poison ivy (Toxicodendron radicans). The chemical urushiol in the sap of poison ivy can cause an allergic reaction in many people that results in an itchy rash. However, wildlife is not sensitive to the plant in the same way. In fact, poison ivy is an important native plant in Illinois with a host of benefits for our natural areas—from food and shelter for birds, mammals, and insects to erosion control on shorelines.
While just the thought may make your throat itch, many animals happily munch away on poison ivy with no ill effects. Deer browse the fruit and foliage. Cottontail rabbits nibble on the twigs and bark. Bees and wasps visit the flowers regularly, gathering much-needed pollen and nectar.
Dozens of bird species eat the round, white, waxy berries that develop in summer and persist through winter. Poison ivy berries provide important sustenance in the fall for yellow-rumped warblers (Setophaga coronata) and other migrating songbirds. These tiny fruits also provide a winter bounty for local avian residents, including red-headed woodpeckers (Melanerpes erythrocephalus), a species of concern that is being spotted more regularly in the Lake County Forest Preserves of northern Illinois. Northern cardinals and American goldfinches have been known to weave the thread like hairs of poison ivy vines into their nests.
Some insects even call poison ivy home. Dimorphic Macalla moth larvae (Epipaschia superatalis) spin a silken haven on poison ivy leaves for protection during metamorphosis, hence its nickname: the “poison ivy caterpillar.”
As long as you look and don’t touch, poison ivy adds beauty to the autumnal landscape, turning crimson as the season progresses. Take our Hike Lake County Challenge and enjoy the last days of fall color, searching (from a distance) for this widespread and beneficial native plant.