Finally, after months of analysis, an event at the Explorer’s Club in New York City recently announced the results of a highly anticipated citizen-science investigation: Central Park is home to about 2,373 eastern gray squirrels.
The Central Park Squirrel Census had enlisted 300 volunteers to track down the bushy-tailed citizens of the 840-acre park over an 11-day count period last October, as Kaitlyn Schwalje at National Geographic reports. According to Eleanor Cummins, a science journalist for Popular Science who participated in the project, the park was divided into hectares, which total roughly the size of a squirrel's home territory. Volunteers then cased the zones, on the lookout for squirrels. Each hectare was surveyed once during the morning and once in the evening, when the squirrels are most active. The would-be squirrelologists also noted behaviors, such as how they reacted to humans (whether they rushed up, chattering for a peanut), how old they appeared, any vocalizations they made and the coloration of their coats.
The organization is selling a $75 report on its overall findings, which includes 37 pages of squirrel data, an audio report on a vinyl 45, five-foot maps of the park and a comparably sized map of all surveyed squirrel locations, and some squirrelly baseball cards. It’s like the hipster version of a scientific journal, with much better fonts.
So who's responsible for this art/science/urban studies mash up? Cummins of Pop Sci reports that the project was first dreamed up by Atlanta-based writer Jamie Allen. In 2011, Allen became curious about how many squirrels were chattering in the trees around him, but could find no good answer to his question. So he and a ragtag group of volunteers conducted the first Squirrel Census in Atlanta’s Inman Park and followed that up with a series of beautifully designed visualizations of the squirrels. A second Inman census was conducted in 2015. Afterward, the group set its sights on tallying Central Park’s squirrels.
You might be asking yourself, why is the group going through all this trouble? “We do it for you. We do it for the city. We do it for the squirrels,” Allen tells Schwalje of Nat Geo, “because it makes us happy.”
It’s also a little bit for science. While gray squirrels are one of the most common mammals in North America, they get surprisingly little research attention. For instance, Schwalje writes, between 1962 and 2012, no one published anything about squirrel alarm calls. Thaddeus McRae, a biologist at Lee University, finally broke that dry spell when he wrote his dissertation on the topic. “Some people are bird people, some people are cat people. Some people love bugs. That can influence choices of what gets studied as much as anything else,” he says. “Squirrels are cute, but so commonplace to many of us that they become background.”
New York City’s squirrels have been through a lot. According to Sadie Stein at New York magazine, deforestation around the city in the early 1800s pretty much wiped out the squirrel population. When a pet squirrel did escape in 1856, it was such a novelty that it attracted a crowd of hundreds that had to be dispersed by the cops.
In 1877 and 1878, between 60 to 70 squirrels were released in Central Park. By 1883, the population rebounded a little too well; an estimated 1,500 squirrels reportedly destroyed trees and other vegetation, leading the city to authorize a squirrel hunt. Over the next hundred years or so, the squirrel and the park came more into balance, and now, as the new project shows, the urban forest comfortably supports more than 2,000 of the critters.
While the census isn’t a peer-reviewed scientific publication, it may have value for researchers. The 2015 Inman Park Census, for example, was used by Emory University researchers to understand how diseases like West Nile Virus can travel through urban landscapes. It’s possible the Central Park data could be used in a similar manner. But it’s also possible that the end result is just a really nice map tallying where all the squirrels in the park were in October of 2018.