By Kyle Durant, SCA Interpretive Ranger
You have arrived at Monadnock State Park excited to hike. The sun is shining, the trees are swaying in a slight breeze and the White Dot Trail stretches into the forest, enticing you onwards. But just out of the corner of your eye you see it, something scuttling through the brush, your first wildlife sighting! Hidden beneath small saplings, rummaging around in a bed of leaves is something small, something dark. Your first thought is a skunk; it’s black like a skunk but you don’t see any white flashing through the leaves. A porcupine perhaps? No, this critter is too small. And then, in one swift movement, it leaps from the underbrush skipping along the trail in front of you before swiftly scaling a tree. You’ve just seen the elusive black squirrel. Unlike a black cat crossing your path, rangers at Monadnock say a black squirrel sighting is good luck!
In my time as an SCA Interpretive Ranger at Monadnock State Park I have seen A black squirrel only twice. On calm days, when park visitation is low, I would often see them scampering around the bathroom, park office buildings or by the picnic area behind the park store.
Black squirrels seen around New Hampshire and greater New England are a melanistic sub-group of the eastern gray squirrel, not their own species. They inhabit the same natural range as their gray counterparts but are much rarer to see. Only about one in every 10,000 gray squirrels have black fur.
The black coloration of these squirrels is the result of a variation in a pigment gene. A 2014 study published in FEBS Letters demonstrated how just a single pigment gene missing a piece of DNA can determine a gray squirrel’s coat color. Subsequently, scientists asked themselves where this faulty gene originated from. In 2019 an answer was proposed in the journal BMC Evolutionary Biology where research claimed the black coats of the eastern gray squirrel were the result of interbreeding between gray and fox squirrels. Fox squirrels have been observed with black coats as well, and crossbreeding is not unheard of. Researchers found that the same allele (MC1RΔ24 allele) is associated with melanism in both squirrels. Lead author of the 2019 study Helen McRobie claims, the most likely explanation is that a male fox squirrel sporting a black coat mated with a female gray squirrel.
Although black morph eastern gray squirrels can be found throughout their range, their frequency depends on the area. Reintroduction programs to replace once thriving black squirrel populations have shown great success in bringing the black morph back to the lower 48. Between 1902 and 1906, then President Teddy Roosevelt released black squirrels into the National Mall and by the 1960’s they could be found anywhere within the capital beltway. In 1915 John Harvey Kellogg released black morphs in Battle Creek Michigan to repopulate squirrel communities that had been declining due to predation and human trapping. To this day, black squirrels occur most frequently in Ontario and Michigan with current day statistics claiming black morphs account for between 50-60% of gray squirrel populations there. And more recently, in the 1960’s Kent State University released black morphs onto its campus to revitalize its dwindling populations. The black Morph is now found with regularity around much of northeastern Ohio.
But how did they get to Monadnock? During the late 1940’s Massachusetts resident Frank Stanley Beveridge, founder of Stanley Park in Westfield, received two shipments of black morph eastern gray squirrels from Michigan. He reportedly released these squirrels into his new park to charm and entice visitors. Since then, black morph squirrels have been found at an increasing rate throughout the pioneer valley and beyond, including in southern New Hampshire.
Many theories concerning the frequency of black morphs have been proposed but two stand out and permeate the literature, concealment and thermoregulation. It has been proposed that gray-coated squirrels have an advantage in deciduous forests, prevalent in the southern stretches of their range. Their lighter coats blend well with deciduous trunks and can provide better concealment in winter months when trees shed their leaves and illuminate more of the forest floor. While to the north, where conifer trees dominate the landscape providing a dimly lit forest floor, black morphs have the concealment advantage over their gray counterparts. Black coats have also been theorized to provide squirrels with a considerably higher cold tolerance and better thermoregulation. Black morphs have been found to have lower levels of heat loss and a lower metabolic rate giving them an advantage in cooler northern climates. This has allowed the black morphs to push the eastern gray squirrels range further north following the last glacial period.
Whatever the case may be, seeing black squirrels can be a rare and rewarding event when out hiking or simply strolling around the neighborhood. Next time you see one of these nutty creatures be sure to appreciate the sighting and pass their good luck on to those around you! For more information about the storied past of the black morph see the resources below:
Region’s black squirrels offer genetics lesson – masslive.com
ADW: Sciurus carolinensis: INFORMATION (animaldiversity.org)
