By Gabrielle L. Wheeler
Across from my sister’s house lives a squirrel that regularly taunts her dog, Leo, by coming into her yard and digging around while Leo barks madly from the living room window. What is unusual about this squirrel, less than its taunting behavior, is its color. The squirrel is jet black all over. Even so, it is an Eastern gray squirrel.
Contrary to what may at first seem nonsensical, Eastern gray squirrels come in two phenotypes, or morphs: gray and black, with gray being by far the most abundant. Black coloring in gray squirrels comes from the absence of a gene which produces lighter pigmentation in the squirrel’s hairs. Another term for this is melanic, which is the opposite of albinism, and produces the dark-colored pigment, melanin, in the skin. The genetic trait that produces black panthers is the same that also produces black gray squirrels.
Ironically, the black phenotype in gray squirrels is a dominant gene. According to Squirrel Mapper, a citizen science project led by SUNY College of Environmental Science and Forestry in Syracuse, black squirrels were very abundant regionally until 150 years ago. Squirrel Mapper is a project is that allows regular, every day residents collect data so scientists at the college can analyze where pockets of black squirrels reside and what pressures determine their locations. The project is exploring questions such as whether more black squirrels live in urban or rural areas, and whether hunting and predation have an impact on black squirrel population numbers.
At this time of the year, both black and gray morphs of the Eastern gray squirrel are collecting nesting materials to fluff up their nests and are courting members of the opposite sex. January is the first mating season for these rodents. Out my kitchen window, I can see crazy squirrels chasing each other up and down fallen logs in my woods, their tails twitching madly in their antics. Eastern gray squirrels produce two litters a year, the first litter will be born in March from this month’s matings.
While I don’t have black squirrels in my woods, I am aware of a few locations nearby where I am sure to see them regularly with just a drive down the road. Participation in the Squirrel Mapper project seems like a fun idea to do with the kids so I might sign us up so we can go a little nuts and keep up with our local black gray squirrels.
For more information regarding the Squirrel Mapper project, please visit squirrelmapper.org.