Most of us are aware that many birds are fond of the fruits and berries found on non-native plants as well as natives.
One of the ways non-native plants spread and become invasive is through the guts of birds. Birds act as seed dispersers moving from one location to another taking invasive plants with them from your backyard to another backyard and often, into wild spaces.
Non-native plants ultimately cannot sustain bird populations because they do not support native insects. Native plants act as host plants and nectar sources for an insect’s entire life cycle, from larvae to adult.
Native insects have evolved such that in their larval form they feed on a small number of plants and do not see non-native plants as food.
For example, native plant expert Doug Tallamy (Bringing Nature Home) writes that while the Kousa dogwood (Cornus kousa), a species from China, supports no insect herbivores in North America, our native flowering dogwood (Cornus florida) supports 117 species of Lepidoptera (moths and butterflies)! Oaks are hosts to an astonishing 532 species of caterpillars.
Many invasive insects thrive here because birds do not recognize them as food. Perhaps you’ve heard of the gypsy moths that are destroying our hardwood forests or experienced hemlock woolly adelgid in your own backyard. Birds seek out indigenous insect species and don’t eat these pests.
Healthy native insect populations are vital for birds during spring migration. During nesting season 96% of songbirds feed their young on insect protein.
It starts with native plants. NATIVE plants + NATIVE insects = healthier bird populations.