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The Northern Flicker is a striking, lively woodpecker with a large bill. 
The brilliant leaves of Poison oak, in the late fall, with its waxy and pale off-white berries.
A Red-bellied sapsucker eating poison oak berries.
The abundance of poison oak berries in a winter patch.
A good look at the long and pointed sapsucker bill.
The underside of a Northern flicker showing the bright orange-red color of its tail.

Wednesday, January 6, 2021

What are the birds eating out there? That was the question I had on my mind when I went out to our mitigation lands on the south side of Willits, historically called Plasma.  The land contains open pastures, created wetlands, and two oak and ash tree woodlands. The woodlands are always full of birds and today is no exception. There are woodpeckers tapping above my head, one makes a squeaky noise which alerts me that this is a sapsucker. As I look up for it, I see a Red-breasted sapsucker hanging upside down on a poison oak vine. I see it fill its bill with the berries from the tangled vines. Then I thought about how poison oak is one of the plants that help many species of animals survive the winters here. Most woodpecker species eat these nutritious berries. Later in the same forest, I watched a Northern Flicker eating the poison oak berries.

Over time I have come to value and respect this plant. Poison oak, Toxicodendron diversiloba, is mostly found as a trailing vine, but it can also form an upright shrub, and can climb trees, boulders, or walls to heights of 15 meters (50 feet). It is a plant that many people are allergic to, causing them to break out in a blistering rash that is terribly itchy. This is caused by the chemical, urushiol, a sticky pale-yellow oil found in all parts of the plant except for the surface of the leaves, unless they are damaged or crushed. It is a plant that can be hard to identify especially in the winter, when, since it is deciduous, it does not have any leaves and are just little twigs that are easy to miss. But the saying “leaves of three, let it be” is a helpful identifier in the spring, and in the late summer and fall its bright red leaves are an easy indicator.

The good news is that there are soaps and scrubs that can be used after exposure to remove the poison oak oils from the skin. Over time, I have found that I am less susceptible to the allergic reaction to poison oak though I am always cautious to wash-up after exposure and always respect the superpowers of that plant!

Now for some of the reasons why I think that this plant should be valued as an ecologically important part the landscape. Over 60 species of birds depend on this plant’s waxy, white berries which are loaded with vitamins and other nutrients. The berries are used by migrant birds moving through our area in late summer and winter and by our resident birds to make it through the sparse food times of winter. The list of mammals that dine on poison oak include black-tailed deer, tule elk, black bears, wood rats and chipmunks. The shrub is home to many small mammals and birds including California quail, rabbits, and voles.

The poison oak plant is a soil stabilizer, helping with erosion of hillsides and road banks. It keeps non-native invasive plant species from spreading with its own spreading habit.

As I was researching the value of poison oak, I found many resources, especially other articles praising the importance and benefits of this plant. It is part of our landscape, and even though I do not know anyone who plants it in their yards, I did read that it is used in Europe as a garden landscape plant because of its beautiful fall colors and the berries which birds are attracted to!