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What About Those Black Squirrels?
Mention that you’ve seen a black squirrel to most Greater Cincinnatians and folks will think you’re color blind. Mention the same in Ft. Mitchell, and you’ll find that just about everyone sees and even feeds black squirrels.
Don Hellmann of Leathers Road in Ft. Mitchell loves to feed the squirrels. “I feed the squirrels every day and there’s always one or two black squirrels around”, said Don. Whereas Don enjoys watching “his” squirrels, he’s also preserving his father’s memory.
Don’s father, Norbert Hellmann, also enjoyed the squirrels at his home on Princeton Ave. in Ft. Mitchell’s Sunnymede subdivision. Norbert would frequently visit his aunt and uncle in the Detroit, Michigan area where he noticed an abundance of black squirrels. He trapped two black squirrels from Detroit and released them at his Ft. Mitchell residence. His black squirrels thrived and bred with resident gray squirrels and produced more squirrels, gray and black. Now more than 30 years later the black squirrels we see in Ft. Mitchell, Lakeside Park, Edgewood, Crestview Hills, and beyond can be traced to the two black squirrels that Norbert released. Norbert passed away in 1977, though his legacy lives on with our many resident black squirrels.
The black squirrels being seen around town are really eastern gray squirrels (Sciurus carolinensis) with a genetic mutation that causes excessive pigmentation or “melanism”. Biologists estimate that nationwide about one of every 10,000 gray squirrels is the black mutant.
Black-phase gray squirrels are by no means a genetic mistake. Gray squirrels in New England, Pennsylvania, Michigan and other northern states were almost all black before the days of early European settlers. The black fur more readily absorbs heat from the sun’s rays providing warmth during cold northern winters; equally important, the black coloration is a defense mechanism.
Dr. Bill Hamilton, a biologist with Penn State New Kensington, explained; “early northern forests were very primeval. They were very shaded, very dense and dark. It’s said that they were so dense that a squirrel could go from one end of the state to the other without ever touching the ground. The undisturbed North American population of gray squirrels was, according to historical records from the 1600’s and early 1700’s, predominately made up of black-phase gray squirrels due to the effectiveness of the black coloration as an aid in hiding from avian predators such as hawks or owls”.
As Europeans settled the New World, forests were cleared for farmland
and squirrels were commonly hunted. Dr. Hamilton added, “as the
continuous forests of Pennsylvania and on westward were broken up and
the human hunting and bounty pressures on squirrels were increased, the
black form of the gray squirrel, even though it is the genetically
dominant variant, became less and less abundant. The black squirrel was
very clearly outlined against the light colored sky when humans hunted
squirrels from the forest floor. This human hunting pressure apparently
favored the mixed, “gray” coloration that even today predominates in
most North American populations”.
Intense hunting pressures in northern states caused the black-phase
squirrel to mutate to the now common gray color in a relatively short
period of time. Dr. Hamilton added, “the impact on gray squirrels was a
classic example of natural selection that can take place over a period
of only decades”.
Nature’s Way is sponsored by Highland Cemetery. Visit Penn State New Kensington’s website for information on a variety of wildlife species at www.nk.psu.edu/naturetrail. You can contact Gayle Pille for nest boxes.