Bringing Nature Home: How You Can Sustain Wildlife with Native Plants

by Douglas W. Tallamy

In a diverse ecosystem, many species perform similar tasks. Penstemon flowers, for instance, might be visited by three species of bumblebees, five species of moths, and one hummingbird species. If one or two of those pollinators disappear, the plants will still be pollinated and make viable seeds. The rodents that eat those seeds will still have food, as will the screech owls that eat the rodents. Redundancy in pollinators will save the day. But if the ecosystem is depauperate in pollinating species, the loss of one pollinator might quickly lead to the local extinction of the penstemon population. This would not only hurt the rodents and the screech owls, but it would also lead to the extinction of all insects that eat only penstemon leaves. These losses would then reduce the food available for all insectivores that included those insect specialists in their own diets. If this food reduction were large enough, insectivorous birds that bred in the area would not be able to feed their young, and they too would be lost from the ecosystem.