CRITTER CHRONICLES: Eastern Gray Squirrel (also comes in Black)

Furry shades of gray! Our common native nut-gatherer shows a dark streak in NW Philly. 

Since it’s February, we were all set to feature Groundhogs — until we learned they were squirrels! 🤯 As are chipmunks, somehow. 🤯🤯 All these furry fauna members of the “Sciuridae” family (pronounced “SKYOOR-uh-dee”)  of which the Eastern Gray Squirrel is by far the most plentiful species in our area.

Don’t let the name fool you! Observant Philadelphians may have noticed a shiny new variation that’s jet-black from furry ears to pointy toe claws. This sable twin is not a different species, but a genetic quirk called “melanism” which causes a squirrel to overproduce melanin, the pigment that colors their fur.

Melanistic squirrels will have black or dark brown coats and also dark noses, mouths, whiskers, etc. It’s like an albino, but but instead of having no pigment they have much more of it than usual! Melanism occurs throughout the animal kingdom, a rare but prevalent trait in birds, mammals, reptiles, fish – even insects.

While the mutation occurs randomly, it’s also hereditary. A squirrel’s dark coat often carries down to his/her offspring – which has definitely happened at Jefferson University’s East Falls campus. Two years ago, spotting a black squirrel was big news in the neighborhood. Now there are whole populations of them in East Falls green spaces.

Speaking of, the formal term for a group of squirrels is a “scurry”; females are called “does” and males are “bucks.” Squirrel babies? Kits!

Though melanistic squirrels are the same species as their gray brethren, they tend to be more tolerant of cold, and have a lower metabolic rate. While they might have an advantage in urban environments where their dark coats are more easily camouflaged, on the other hand, being hard to see is probably a major liability around traffic. Otherwise, there seems to be no significant impact on mating, territory, or other matters necessary for survival.

As seen on a popular East Falls community group

The average life span of a squirrel in Philadelphia is about 6 years; the maximum age recorded in the wild is 12 years, although in captivity they’ve been known to live up to 20 years. Squirrels breed twice a year, in early spring and late summer. A mama squirrel gives birth to 2 – 4 kits, which she cares for by herself. Males generally don’t participate in the caregiving, and will usually live nearby in their own separate nest.

Have you seen black Gray Squirrels in your neighborhood? Tell us where in the Comments below, or send us your pics on Facebook, Instagram or good old-fashioned email.


  1. They’re nature’s little acrobats, able to leap 20 feet between trees thanks to their strong hind legs and fluffy tails, which help them balance and steer through the air. On the ground, they can run 20 mph.
  2. Squirrels also use their tails to communicate with flicks, twitches, and swishes. They also have an excellent vocabulary of vocalizations, from chirps to chatters, including three distinct alarm calls: “kuks”, “quaas”, and “moans”.
  3. In addition to nuts, a squirrel’s natural diet includes berries, fruits, buds, bark, mushrooms, and even the occasional bug or caterpillar.
  4. Squirrel nests (called “dreys”) are cozy bundles of leaves, twigs and scavenged materials built in tree trunks or upper branches, and occasionally attics or other dangerous human spaces.
  5. Only 15 – 25% of newborn squirrels make it past their first year; litters born in tree dens are much more likely to survive than those being raised in leaf nests.
  6. Although squirrels don’t hibernate, when temps dip below 30 degrees they will spend days sleeping in their nests until weather clears.
  7. Up to 74% of the nuts squirrels bury are never retrieved. One squirrel buries thousands of caches per year — lots of these will sprout into new trees, perpetuating the forest.
  8. For rodents, squirrels are highly intelligent. Research show they can learn complex mazes and simple puzzles to access food rewards. A 2019 study suggests they may be smarter than dogs!
  9. Squirrels are lovers, not fighters. The majority of aggressive behavior amounts to chasing and bluffing, rather than actual combat. They’ve even been known to buddy up in extra harsh conditions, and platonically share a den together.
  10. Squirrels can spread tick-borne diseases to humans, and also carry ringworm, typhus, and bubonic plague. Squirrel feces and urine can contain salmonellosis. While squirrels can catch rabies, they generally won’t live long enough with it to spread the virus.

⚠️ WILDLIFE ALERT: Our built environment can be dangerous for squirrels. If you encounter a sick or injured squirrel, contact a qualified wildlife rehabber like Philly Metro Wildlife Center, where licensed professionals provide healing and temporary refuge.  They’ve also got a handy “What To Do” decision tree to help walk you through bird, mammal, and reptile crises outside of operating hours. Open daily 10am – 4pm, 267-416-9453

The Schuylkill Center in Roxborough also has a Wildlife Clinic at 304 Port Royal Ave, open 7 days/week with a drop-off shed for after hours, call 215-482-7300 or visit for more info.

Thoughts? Opinions? Strong feelings about which other native animals we should (or shouldn’t) highlight in this year of local fauna features? Please leave your comments below or email

Stay tuned for next month’s spotlighted species, and meanwhile get ready for shed hunting season! All the details in last month’s Critter Chronicle on Whitetail Deer.

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