Q. I have a sugar maple in my yard that is my pride
and joy. I was alarmed to notice that the trunk is turning black.
Can you look at these photos and tell me if you see anything I
should be concerned about?
A. The photos
show a distinct blackening of the bark, along with a row of small
holes. This is the handiwork of the yellow-bellied sapsucker, a
species of woodpecker common in western Pennsylvania. These
medium-sized birds are barred black and white with bright red heads.
Males also have a red throat. And yes, they have pale yellow breasts
Sapsuckers are migratory birds
that spend winter in the southern United States, Central America and
the Caribbean and summer in the north. While insects are a major
part of their diet, they also feed on sap. They test trees and feed
only in those that have the best quality sap – high in sugar and
Sugar maples are favored for
the same reason that humans tap them. Other favorite trees include
aspen, birch, magnolia, maple, poplar and pine. These birds will
feed on more than 250 species of woody plants.
In this case, the damage is
nothing to worry about. The blackening of the bark comes from excess
sap dripping down the trunk being colonized by fungi. The fungi are
not damaging to the tree but grow on the carbohydrate-rich sap. It
is similar to the sooty mold that grows on the excrement of certain
insects that we politely call “honeydew.” The flowing sap may
attract other birds, including hummingbirds as well as bats,
porcupines and insects such as bees and wasps.
Sapsuckers create two
different types of damage to collect sap: horizontal rows of small,
deep holes and shallow rectangular holes that damage the tree’s
cambium tissue. The second type of feeding is more serious because
it can affect large sections of bark, creating easy entrance into
the tree for insects and disease-causing organisms.
To prevent this type of damage,
wrap the trunk in burlap and pin it in place until the worst of
their feeding is past. Then the wrap should be removed. However,
this is not necessary for you because the damage is pretty minimal.
Trees vs Lawns