7-16-07
With squirrel season only a month hence, we launch
today’s column with a question from Tom Roach, a Bloomington reader of
my web page, who asks about squirrels eating the inner bark (cambium) of
beech trees.
The cambium, as I see it, is a pithy, paper-like
substance between the hard, outer bark and the wood of a tree (including
limbs). In short, I guess, it would be good to say it is the tree’s method
of growth.
Incidentally, having observed this natural phenomenon
for many years, I would also say this eating occurs much more often on
wrist-size limbs and those smaller than trunks of trees. This probably
is caused by the fact that a squirrel can bite better on small, or relatively
small, limbs.
Tom writes:
“I have noticed here lately the fox
squirrels in the courtyard (Wright Quad, Indiana University, Bloomington
Campus) are eating bark!!! Have you ever seen such a thing? They are ripping
the bark off of Beech trees and eating the softer inner bark and dropping
the hard outer bark just like a hickory nut cuttin’.
“The whole courtyard is littered with bark
chunks... It is my humble opinion that they are probably starving as I
have also seen them eating immature acorns as wel1...If you are so inclined
I would be happy to show you in person... Some of the branches have as
much as 4 or 5 feet of bare bark where the squirrels have eaten it... photo
op?????? Just curious if you had ever seen anything of this nature.”
What’s this all about, Tom questions? Why do squirrels
eat the inner bark of the trees, and drop the hard outer bark to the earth?
As Tom notes above, this behavior of squirrels
probably is brought about by a shortage of food, in this case probably
caused by the drought, especially since the squirrels have recently fed
on immature acorns of oak trees.
Normally, however, it is a condition that exists
in the late winter or early spring when supplies of other foods squirrels
use can get low.
Incidentally, the opening of the aforementioned
squirrel season (entire state) is August 15. More on that later.
ON HUMMERS--Still
another reader, Jim Wall, sends word of strange behavior on the part of
the delightful little hummingbirds of summer (ruby throat, mostly).
Jim and his wife live east of Muncie, and have
sugar-water feeders out for hummers every summer. He tells me that recently
the hummers ceased to come to his feeders, and is wondering if other nature
lovers are experiencing the same.
I have a sneaky suspicion that this behavior may
somehow be related to the drought conditions that have existed in Central
Indiana since spring of the year. I, of course, would be very interested
if others have opinions or facts on the matter.
Spot checks of friends throughout the state have
revealed nothing unusual.
Ordinarily, the hummers don’t migrate south (and
then to South America) until the blooms of summer subside. But it could
be that they move to more fertile grounds.
Mother Nature tends to give her children built-in
facilities for deciding on the issues.
IT’S A FACT--The
artistically striped chipmunk spends most of its life on the ground, thus
placing itself in a group known as ground squirrels. But it is an adept
climber, seen occasionally scampering through the trees.
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