Cedar waxwings are one of the few North American birds that specializes in eating fruit. It can survive on fruit alone for several months.Photo: Kelly Colgan Azar/Flickr
It seems a cruel irony that Monrovia has the plant heavenly bamboo (Nandina domestica) listed as bird friendly, yet birds can die of cyanide poisoning from eating the berries.
Cedar waxwing deaths, in particular, have been documented in Georgia, Houston and other parts of the country. One case last spring had a Decatur, Georgia, resident Charles Reid discovering a flock of 14 dead birds outside Decatur High School’s front entrance.
“Initially, when I stumbled upon them, it was pretty horrific and shocking,” Reid told Decaturish.com. “You don’t find this that often.”
Reid reached out to Georgia Birders Online, and soon the manager of the listserv, Steven Holzman, contacted Reid and asked for him to submit a frozen sample for testing.
“I took it to the Southeastern Cooperative Wildlife Disease Study,” said Holzman, president of the Georgia Ornithological Society. “They did what’s called a necropsy on the bird, and they gave me a clinical report. They diagnosed the bird as dying from cyanide toxicosis.”
Heavenly bamboo is a popular plant for its autumn foliage and its bright berries.Photo: Blue Water Baltimore
The culprit was none other than the heavenly bamboo. While cedar waxwings mostly feed on serviceberries, mulberries, raspberries and other fruits, when they have exhausted their normal food supplies they will begin to eat the Nandina bushes’ berries as well.
Heavenly bamboo is not a real bamboo, but an evergreen plant that produces bright red berries. It was introduced to the United States in 1804 from China and Japan as an ornamental plant and proved to be an attractive specimen that grew quickly.
It is now classified as an invasive plant, according to the U.S. Department of Agriculture, and can easily spread via suckers and rhizomes as well as through seeds from its fruit.
Despite homeowners’ best intentions of providing food for birds during the winter, Nandina is not the answer as the entire plant is poisonous and the berries contain cyanide and other alkaloids that create the highly toxic hydrogen cyanide.
Herring Run Nursery suggests winterberry as a good native alternative to those who are looking for a shrub that produces beautiful red berries. If your client has their heart set on keeping their Nandina bushes, stress the importance of pruning the bushes to remove the berries before winter.
Because the plant can thrive in unforgiving areas and it is hard to eliminate it once it has been planted, it is far better to place natives or non-invasive alternatives that can still make the space beautiful. Click here for some other bird-friendly alternatives.
