Early one morning last month, Laura Dudley Plimpton found herself in Forest Park, in Queens, staring at a pair of captured raccoons. It was not the first time that Plimpton, an ecologist at Columbia University, had caught two of them in a cage trap designed for one. But typically when that happened, she would find a mother and a small kit inside.
This trap contained two fully grown, rotund adults, two balls of bristly fur that had merged into what one member of the trapping team called a single “big squish.” The raccoons seemed to be unbothered, one resting casually atop the other inside the cage, which had jumbo marshmallows as bait.
“You guys are so silly,” Plimpton said. Her demeanour was improbably cheery, and her French braid was impressively neat for someone who had arrived at the park before dawn. “I really don’t know how they did that,” she added, turning toward a colleague. “They had to have raced each other to the marshmallow.”
For their trouble, the raccoons had earned themselves a quick veterinary exam, a rabies vaccine and a spot in Plimpton’s investigation: a study of urban animals, the pathogens they carry and how they might spread across the city.
Although rats receive most of the attention, New York City is crawling with all kinds of creatures — raccoons, skunks, opossums, deer and even the occasional coyote — that are not always visible to people. For these animals, urban living provides some clear opportunities, especially “if they learn to utilize human resources such as trash,” said Maria Diuk-Wasser, who leads Columbia’s eco-epidemiology lab, where Plimpton is a Ph.D. student.
But city life also poses distinct challenges for animals, which often live in close quarters and have frequent interactions with other species, including us. That can raise the risks of disease transmission to people, pets and wildlife.
So Plimpton, Dr. Diuk-Wasser and their colleagues are trying to learn more about these risks, in hopes of safeguarding both human and animal health. They are also shining a light on the way that our lives are intertwined with those of our animal neighbors, even in one of the most urban environments on Earth.
“We have all of these such close interactions with each other, whether we know it or not,” Plimpton said. “It’s always happening around us.”
For years, Dr. Diuk-Wasser has been investigating how urban environments shape animal communities and how that, in turn, might affect the spread of certain pathogens. She has been especially interested in tick-borne diseases and exploring how landscape features on Staten Island affect the movements of deer, which drop ticks as they bound through the borough. “We have identified a strong correlation between deer visitation and finding ticks in someone’s yard,” Dr. Diuk-Wasser said.
The Covid pandemic provided an opportunity to expand the research, especially when it became clear that people were regularly passing SARS-CoV-2, the virus that causes Covid, to deer, cats and other animals. The universe of coronaviruses is vast, and Plimpton and Dr. Diuk-Wasser wondered whether there were other coronaviruses circulating in the city’s wildlife that might pose a risk to animals or people.