THE WILD SIDE
Guest Column by Maria de Bruyn
Many of us visit garden centers and nurseries to find new plants to beautify our natural surroundings or we receive cuttings and seeds from friends and neighbors. Some of these admittedly pretty shrubs and trees may be invasive, however, and can take over an area, crowding out native plants.
There is one invasive plant in particular that can also be harmful to a bird that many people really love, the cedar waxwing. That plant is the Nandina domestica (also known as heavenly or sacred bamboo).
Nandina berries can contain high concentrations of cyanide compounds, which cause bleeding, toxicity and organ failure when birds eat them in very high numbers. Cedar waxwings in Georgia and Texas have died of cyanide poisoning after eating nandina berries.
American robins, Eastern bluebirds and Northern mockingbirds may also eat them, but they likely ingest low quantities because these birds also eat insects and seeds in the autumn and winter. Cedar waxwings, on the other hand, have a winter diet that almost exclusively comprises berries and they tend to gorge on them when they find a good source.
In our area, they may also eat the berries of native hollies, invasive buckthorns and privets but these plants don’t seem to harm them, though the birds could become intoxicated if they eat a lot. (The birds in the photo are eating American serviceberry fruit in the springtime.)
In January, some UNC employees unfortunately discovered the bodies of several cedar waxwings that had died in the vicinity of nandinas. It is not yet known what caused their deaths. Possibilities include: window strikes; inebriation from fruit, followed by falling out of a tree and breaking their neck or freezing to death; and poisoning by some agent in the environment, one of which could have been nandina.
To save the lives of the beautifully elegant waxwings, it is best to remove this non-native plant from your yard or neighborhood — or at least cut off the berries and throw them into the trash in a container so the birds don’t find them on the ground.
To replace the nandinas in your vicinity, there are other berry-laden native plants that are visually attractive and can provide winter food for the birds that won’t endanger those elegant waxwings: American beautyberry, American holly, chokeberry and Northern spicebush. If you see nandina berries in your vicinity, please consider what you can do to get rid of them!
Maria de Bruyn, a medical anthropologist, is a member of the Chapel Hill Bird Club, the local Audubon Society and hosts a blog focusing on wildlife at https://mybeautifulworldblog.com/