Sunday, January 28, 2024

They Won’t Change Their Behavior


This is the time of year when the fruits of the exotic Nandina domestica shrub are particularly noticeable and reminders go out from conservation groups to remove the fruits (and even the shrubs) to protect birds. Shrubs like these were recommended in the past to support fruit-loving birds – called frugivores – during the winter. So why now the change to remove them to protect birds?

Cedar Waxwing

The advisement is primarily to protect Cedar Waxwing birds, a Georgia winter resident that sometimes gorges on abundant fruits. The fruits of nandina contain cyanide and other alkaloids. In small quantities, it appears that most birds are not harmed but there have been several incidents in Georgia (Decatur and Thomas County) specifically where Cedar Waxwings have died. It is generally understood that poisoning occurs when the fruit is ingested in large quantities, such as when gorging.

Some people think this harm is overhyped – that the number of reported cases is too low. However, it takes a lot of effort to determine what killed a bird, assuming someone reported the deaths to begin with. So it is very likely that the deaths are underreported. Some people have even suggested it's the birds fault. 

Bottom line: these birds aren’t going to change the way they feed (i.e., gorging occasionally) in our lifetime so using nandina and hoping for a different outcome isn’t a viable approach. We have the big brain. It’s up to us to do the right thing.

Nandina domestica

I should also mention this plant is tracked as an invasive species in Georgia, capable of creating new populations thanks to spread by wildlife. I pull out 2-3 new seedlings per year in my yard; if all 47 homes in my neighborhood also got two new seedlings per year that would be 98 new plants per year in just my neighborhood.

In addition to those two reasons for avoiding this plant, know that if you instead use a regionally native plant, you’ll be contributing to the ecosystem and likely providing more support for birds even if that plant doesn’t have fruit. If you’re planting shrubs specifically for fruit, choose something else.  

There you have it: 3 reasons to get rid of nandina in your garden (or avoid adding it). When we know better, we can do better.

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