Scientifically speaking, a squirrel is just a rodent, sharing this status with mice and rats, fellow denizens of New York City parks. But something about these wide-eyed, bushy-tailed fearless acrobats draws the attention of any park-goer.
That’s what inspired 72 New Yorkers to venture into parks for a single afternoon in early March 2020 to count and observe squirrels in 24 parks in Manhattan and Brooklyn. Their findings, entitled Squirrels, Parks and the City: A (very serious) data-gathering expedition, were released Friday by The Squirrel Census. The results are accessible through NYC Open Data, a site that publishes free public data provided by city agencies and other groups.
This census, which is run by a rag-tag group of data scientists and moonlighting naturalists, spotted 433 squirrels overall. Tompkins Square Park in the East Village had the most sightings. Four parks — Sternberg and Cooper Parks in Brooklyn as well as Thomas Paine and Sara D. Roosevelt Parks in Manhattan — recorded zero sightings. Grey squirrels were the most common (390 total), followed by cinnamon-colored squirrels (26) and then black squirrels (16). One squirrel entry wasn’t labeled with a color.
The Squirrel Census originally started in Atlanta in 2012 by Jamie Allen simply to answer the curious question of just how many squirrels live in the park. It has since migrated out of the South, and this is the second edition in New York. The last version, published in 2019, only looked at squirrels in Central Park.
The squads of volunteers change, but the mission remains the same. When the census decides to count in a particular park, anyone can sign up — no experience necessary.
These datasets are the first of their kind for these parks, and provide vital scientific information about urban wildlife. Very little is known about city squirrels nationwide, and scientists say the furry mammals can offer clues to how other animals might adapt to climate change.
And along with data spread across two boroughs, the new release is accompanied by a toll-free number, 1-833-NYC-SQRL, where the public can now listen to the experiences and information collected by volunteers. This hotline includes an option to listen to a song about these impish creatures.
“There’s a lot of questions that we have about urban organisms,” said Elizabeth Carlen, an evolutionary biologist researching urban squirrels at Washington University in St. Louis who was not involved with the census. “And if we had these historical datasets, which now The Squirrel Census is building, we can begin to ask those questions.”
Squirrels offer these insights because they’ve been adapting to humans for a very long time. They evolved from fleeing people as perceived threats to eagerly approaching tourists for food at the southern end of Central Park. These adaptations are important to study for climate change, according to one of The Squirrel Census’ scientific advisors, Colin Jerolmack, chair of environmental studies at New York University.
He said more and more animals are being displaced from their natural habitats or struggling to find food sources because of climate change or urbanization. Studying squirrel behaviors can tell us which animals already have the habits to thrive going forward and which ones might need assistance in the future.
“As more natural environments are harmed or taken away from them, you’re going to see more and more animals adopting more of the behaviors of squirrels,” said Jerolmack, who participated in the census count with his 4-year-old son.
But the staff and volunteers of The Squirrel Census also say that the information exists for its own sake.
“As New Yorkers we tend to hurry from place to place and not really stop,” said John Murray, chief squirrel correspondent for The Squirrel Census. “We encourage a little bit of appreciation of our environment. What people do with the data is up to them.”
How The Squirrel Census Gets Made
On a cold December morning over a hectare of Central Park demarcated by the Bow Bridge, Murray and Stuart Bowler, northern liaison for The Squirrel Census, walked Gothamist through their data-gathering methods. They stood with clipboards clutched to their chests and No. 2 pencils, scanning the ground back and forth and then looking up in the crook of tree branches for 20 minutes, the time allotted for the count of each of the 350 sections of the park created from a topographic map made by their own cartographer, Nat Slaughter.
Each section was counted on two different occasions for accuracy. While double-counting a squirrel does happen, the census uses a formula adapted from squirrel biologist Vagn Flyger that accounts for missing one of these short-haired denizens or counting them twice. It’s adjusted by one of their scientific advisors, Donal Bisanzio, a human and animal epidemiologist at RTI, a nonprofit research institute with a mission to solve global issues through science-based solutions. The new census of 24 parks is not as rigorous as their 2019 Central Park census, and is a flash count that provides a snapshot.
“See, in that tree, in the fork, there's a little cluster,” said Bowler , finger pointed up into the canopy.
The squirrel nest looked like bunches of dried leaves piled between tree branches, and a gray furry ball emerged from it overhead – one of 2,373 gray squirrels in Central Park, according to their own 2019 estimate.
“That is easily the largest squirrel I have ever seen. Oh my goodness,” Murray responded.
Counting is only a small part of the data that is collected. Volunteers fill out a form that includes details such as the presence of litter and other animals. Many entry lines are also dedicated to detailing a physical description, the critter’s activities and whether it approaches humans or flees.
“No communication – I’d say maybe a tail twitch when she spotted us,” Bowler said as he wrote his observations on the clipboard. “Interaction with humans – approached, and didn’t give a damn.”
For the volunteers, it’s as much a meditative experience as it is a scientific endeavor.
“People loved it,” Bowler said. “The tales they were coming back with -- saying, ‘ah I never believed that I'd have so much fun walking through the undergrowth, you know, looking for little squirrels.’ But it's fabulous.”
The next count may head across the Atlantic Ocean. The organizers are planning a census for Hyde Park in London, where they say a culture war is raging between the shrinking native red squirrel populations and the invasive gray squirrels. The British government encourages the trapping and killing of the gray variety as a means of preventing them from displacing the red ones. They hope their data will help set the story straight.
“There's also a bit of a drama going on in the squirrel world over in England,” Bowler said. “A census over there would be very important in a way just to find out what's going on with the grays [squirrels].”