Still, new animals do show up from time to time — turkeys, red foxes, coyotes. Leslie Day has been watching them come and go most of her life. She lived on a houseboat at the West 79th Street Boat Basin for nearly 40 years, falling in love with the wilder aspects of this urban space. A middle-school science teacher, she eventually got her Ph.D. in science education and wrote three books drawing on her observations and research, including the “Field Guide to the Natural World of New York City,” with entries on, among other city animals common and uncommon, Eastern gray squirrels, rabid wolf spiders, opossums, red-backed salamanders, cabbage white butterflies, common snapping turtles, the Northern rock barnacle, the double-crested cormorant, little brown bats, big brown bats, the American eel, the pyralis firefly and, inclusively, earthworms, which, she notes, “were brought to North America by the early European settlers.”

Day recently moved to land, in Washington Heights, near the George Washington Bridge. Down at the basin she watched raccoons and squirrels, but up in Washington Heights she follows skunks. “Oh, my God, we have a million of them,” she said when we met at her apartment. Skunks have terrible eyesight and live their lives low to the ground, smelling, smelling and being startled. One had taken up residence under Day’s front stoop, she said, and we went out to take a look. There were hundreds of tiny, perfect divots in the lawns surrounding her apartment building, where skunks had stuck their noses into the soil, rooting for bugs.

Image Credit... Illustration by Louise Zergaeng Pomeroy

We walked over to the Heather Garden in Fort Tryon Park. Day pointed to a gap along the terrace — last summer, she said, she had been walking past this very spot with her friend Mike Feller, who worked as the chief naturalist for the city’s Parks Department for 31 years, and they noticed something unusual: a mound of brilliant white sand pierced by a pinhole leading down into the earth. Day thought it might be a sand trap made by an ant lion, a predatory insect, but Feller told her no, it was probably just plain ants. He’d bet anything, he continued, that it was sand someone dredged from the Rockaways and trucked up long ago to make this terrace. The ants go down and excavate it, reminding us of our past. Like the rats, and the woodchucks, and the skunks, and all the burrowing creatures, even us, the ants don’t just walk back and forth, but up and down, through time.

When I got home I called Feller, and he told me about another small but significant journey that happens each spring, one that has been happening since not long after the glaciers retreated thousands of years ago. It isn’t historic, Feller said. Just beautiful.

“On warm, rainy nights, the spotted salamanders emerge from underground and walk 100 yards down to vernal ponds — wetlands that only exist in the spring and beginning of summer — to breed,” he said. “It’s a highly ritualized, synchronized thing that they do: Coming up out of the forest floor, they amble down to the water’s edge, and a male and female do this very intricate nose rubbing. They swim together, then apart, and the male swims down and leaves a little mushroom, a sperm-containing sack, and the female dives down, picks it up and implants it in her. It is a bizarre, aquatic ballet. In a few small spots in the city, it’s happening, right now.”

Most animals make city living better, or more interesting, but animals that eat rats might be especially welcome. Coyotes from the Bronx have devoured many rats in Riverside Park and Central Park, and in April a coyote was sighted all the way down in Chelsea. Smaller rat catchers, like foxes, are not uncommon in London, but they are rare in New York. We don’t make it easy for them. If you’re a fox or a coyote coming in from the countryside, you might try to stick with what you know: dirt, low cover, bushes that hug the ground. You would follow the rail lines, which are open to the air but still overgrown in places, or the parkways, the great green strips that Robert Moses built, or even the older, abandoned Long Island Motor Parkway, between Alley Pond Park and Cunningham Park, in eastern Queens. You would follow them until the concrete takes over completely. And then? Well, it gets harder. (It’s worth noting that probably the greatest predator of rats in Manhattan right now is the red-tailed hawk, which of course moves with far more freedom.)