North America's insects co-evolved over millenia with our native plants, developing intricate chemical relationships which allow them to use native plants for forage and rearing their young. Plant chemical properties both attract insects or repel them. Dr. Douglas Tallamy has been researching the preferred use of native vs. non-native plant species by insects, finding that native plants support a much greater number of insect species (mainly Lepidoptera, i.e. butterflies and moths) than their foreign plant counterparts.
But why does this matter for birds? Most wildlife depend on native insects as a primary food source, either directly or at higher trophic levels up the food chain. For birds, insects are a particularly important food source during seasonal migrations and when rearing young. Lepidoptera are a critically important to even our most common back yard birds. Through observations of nesting Chickadees, Dr. Tallamy found that one mating pair will feed will feed their nestinglings 6,000-9,000 caterpillars from 6 a.m. until 8 p.m. for each of the 16 to 18 days it takes the chicks to fledge. That’s a total of 350 to 570 caterpillars every day, depending on the number of chicks.
Download the resources below for futher information on native plants and their importance to the web of life.
Woody Species, by Genus: Host Plants for Lepidoptera (butterflies and moths)
Landscaping with Native Plants in Western TN