Why Native?

Chickadee with insect food by Margy Terpstra

Native plants are the foundation of a functioning food web, channeling energy from the sun to the plant to the plant-eater to the animal-eater and back again through decomposition. Unfortunately, nearly all of the landscape where most of us live is mowed turf grass or non-native flowers and shrubs. Those imported plants do not support the food web in this their adopted country.

For a clearer picture of that food web, consider the case of North America’s songbirds – nearly all of which require insects during their life cycle. In fact, 96% of all land birds on the continent consume insects during their life cycle. This includes cardinals, chickadees, wrens and even hummingbirds.

The insect-eating is driven by the need for protein. Baby birds cannot build muscle and bone without it, and adult birds require protein to replace their feathers after breeding. Insects are the right size for songbirds to consume and packed with protein more densely than red meat. Insects are also vital protein sources for amphibians, reptiles, freshwater fish and many rather large land mammals.

Tufted Titmouse with insect food by Margy Terpstran

The great majority of those eaten insects are plant-eaters (herbivores) which are mostly specialists, eating only one or a few species of plants. Plants primary defense against being eaten is to create chemicals in their tissues. They cannot run or hide to escape predation, but instead make themselves unpalatable to all but the small number of critters that evolve to digest those chemicals. In total, 90% of plant-eating insects are specialists. The Monarch butterfly caterpillar is the most well-known example; it only eats milkweed. 

All that specialization means insects and the plants they eat (pollinate, nest in, etc.) have evolved together over eons and depend upon each other. Yet, that relationship is severed when we displace the native plants (and their insects) when building our homes and businesses and replace them with non-native plants. The imported plants come alone; their insect “partners” are left behind in their home country. The transplants will eventually become a part of a redesigned food web, but in evolutionary time scales. There are non-native plants in North America without a single native insect consumer 50, 100 or more years after their introduction to the continent.

8-Spotted Forester Moth by Mitch Leachman

Reintroducing native plants to our landscapes is key to restoring the food web for our songbirds, all the other critters and for our own health. It’s the right thing to do, but it also yields a much more interesting landscape. Birds, butterflies, bees and all that “insect food” are beautiful and inspiring all on their own.