I would like to start a series about the natural resources that winter resident birds have at their disposal. Hopefully at least one of us will keep up with this and post an interesting insight we’ve had into what environmental features helps birds survive winters. Although Arkansas very rarely experiences harsh winters, we still have a few days where birds have to batten down the hatches. The main focus, as the name suggests, is on the natural food that wintering birds find. In warmer times, a lot of our birds rely heavily on insects. When it is too cold for the insects they will turn to grains and fruits. Both species of plants that I would like to cover in this installment were unknown to me as bird foodplants until this year: Poison-Ivy and American Beautyberry.
Poison-Ivy (Toxicodendron radicans), as both the common and scientific names suggest, has a chemical that humans find irritable. The plants produce urushiol which is believed to be more of a water conserver than a defensive chemical. However it was intended by the plant it leaves a nasty rash for those allergic. They produce clusters of whitish to tan berries that several species of birds will eat during the fall and parts of winter. The plant may rely on the consumption of its berries for the dispersal of its seeds. This may mean that the plant doesn’t produce as much, or any, of this chemical in the berries (I haven’t done that much research on it). Or, birds are not as susceptible to the chemical’s effects. In Arkansas, this plant is incredibly prolific around forests. It can be a vine (most common form) or even a shrub/tree. I’ve seen Yellow-rumped Warblers and Ruby-crowned Kinglets eating these berries and have read that Downy Woodpeckers favor them. They provide very little in the form of cover which is another aspect winter birds have to consider.
American Beautyberry (Callicarpa americana) is not irritable as a whole but its berries can be unpalatable and produce astringent chemicals. An astringent is something that tightens tissue and can be harmful if eaten in large amounts by humans. Once again the plant may rely on birds to disperse the seeds by eating the berries. The leaves are favored by herbaceous mammals, especially White-tailed Deer. This shrub produces leaves that kind of resemble an hydrangea. In the fall it has bright purple berries that remain after the leaves fall off. I have read reports that multiple species of birds like to eat these berries but I have only seen Dark-eyed Juncos eat them. One website says that this is an important plant for Northern Bobwhite who eat the berries. It is very common in the understory of forests and at the forest edge. In the winter it just looks like a few twigs coming out of the ground with bright purple berries.
These native plants are of negative or neutral consequence to humans but they do attract their fair share of avian suitors. Although neither offers sufficient cover, they provide another valuable resource for birds during the fall and winter months.