The legend begins thus: In 1967 — or maybe it was ’66 — a pet store truck overturned in Long Island, sending a few dozen finger-length Italian wall lizards scampering into the bushes of Garden City. There Podarcis siculus thrived, slurping up arthropods along rock walls and sidewalks, dodging beaks and claws and tires. Over the decades, the lizards, elegant Mediterranean natives whose emerald torsos taper to long pewter tails, turned up in Brooklyn, Queens, and the Bronx, flourishing in drainage ditches and grassy cemeteries. One amateur biologist estimated their dispersal rate at a block per year.
As far as scientists knew, however, the animals didn’t trespass north of New York City. Until, this summer, in Hastings-on-Hudson — the Westchester town, 40 minutes above the city by rail, where I grew up — I saw one.
I spotted my wall lizard as it scooted across, sure enough, a cobble wall; obligingly, the creature basked for a moment in the late afternoon sun, its bejeweled throat pulsing lightly. I snapped a grainy iPhone picture and tweeted it to two herpetologists I knew. Twenty-four hours later, Colin Donihue and Max Lambert were prowling my parents’ neighbor’s yard.
My sighting had been no fluke: Italian wall lizards flitted through the pachysandra, dove into rocky crevices, crouched at the base of pin oaks. Lambert carried two mesh dipnets, the kind you’d use to scoop detritus out of an aquarium. Donihue toted a fishing pole outfitted with a string noose at its tip. He’d employed the apparatus to snare some 1,500 lizards during the course of his Ph.D. From the sidewalk, young couples pushing strollers shot us curious glances.
“This is going to be a patience game,” Donihue sighed as a lizard vanished into a crack. Lambert asked the elderly homeowner if she knew that her property had been colonized. Sure, she said — they’d been here for 10 years. She’d thought they were salamanders.
After two hours of fruitless pursuit, Donihue got a bead on one — a big, bold female perched on a root. Delicately, as though defusing a bomb, he lowered his tiny noose over the lizard’s head and, with a jerk, yanked it into the air. The animal squirmed, kicking at space. Donihue slipped it into a blue cloth bag and knotted it shut: the northernmost Italian wall lizard ever captured in New York State, destined for genetic analysis and museum enshrinement. A sacrifice to science.
Acrid feces trickled down Donihue’s hands. He’d left home at 5 am for this hunt, and he’d begun to take on a slightly delirious, Ahab-ish aspect. “Ah, the sweet smell of lizard crap,” he said, grinning wildly. “The smell of victory.”
The capture, however, raised more questions than it provided answers. How had the lizards navigated the 30 miles from New York City? Donihue hypothesized that they’d found their way to Hastings along the MetroNorth railroad corridor, whose warm, rocky trackbed afforded prime habitat. But maybe they weren’t related to the metropolitan lizards at all. Could they be a separate introduction? Perhaps wall lizards had spread to Hastings by stowing away in potted plants, like anoles. Or had they been released by a lonely Italian expatriate, as in Los Angeles?
Donihue, like all biologists who study New York’s wall lizards, faced other conundrums. Namely, how were these Mediterranean transplants surviving the frigid New York winters? Huddled beneath the hot steam wafting from a laundry vent? Burrowed deep in the soil (the prevailing theory)? Tucked in a compost pile, their tiny bodies warmed by the decomposition of rotting leaves?
However they’re managing it, Italian wall lizards — ecological generalists and evolutionary speed demons — are indubitably among the winners of the Anthropocene lottery. When the lizards were introduced to a leafy island off the Croatian coast in 1971, they rapidly developed wider heads, stronger jaws, and expanded guts to better chew and digest vegetation. In Greece, where Donihue studies a close cousin called — you guessed it — the Greek wall lizard, reptiles that live on human-built rock walls have evolved elongated fingers and toes, an adaptation that may suit their new “lurk-and-burst” hunting style. (Lizards in more pristine settings trot continuously between bushes in search of insect prey). Colonies have established in Los Angeles; Topeka, Kansas; and Greenwich, Connecticut.
I consider myself an anti-invasive species hard-liner: I’ve squashed cane toads in Australia, speared lionfish in Honduras, bashed the heads of lake trout in Yellowstone. When it came to Italian wall lizards, however, I couldn’t summon my usual nativism. Instead, I found myself admiring these intrepid pioneers, eking out a living so far from their sun-dappled olive groves. Besides, what harm were they doing, really? As Lambert pointed out, Hastings-on-Hudson lacks lizards of its own, so P. siculus isn’t ousting native fauna — instead, it’s filling an unoccupied niche. (Granted, that’s not the case in Los Angeles, where Italian wall lizards may be pushing out native counterparts.) Rather than fretting about hypothetical damage, I delighted in my own native ecosystem becoming one species more complex.
I’m not the only one beguiled. Italian wall lizards have served as reptilian ambassadors everywhere they’ve appeared, windows upon the wild for people perpetually surrounded by glass and steel. In Topeka, a herpetology professor conducts an annual population survey, beloved by the community, dubbed the “Running of the Lizards.” Parents and teachers across New York’s boroughs have incorporated the immigrants into their lessons; in Long Island, one nursery school adopted them as mascot. Outgoing school presidents receive a noble bit of treasure: a golden lizard pin.
Soon after our expedition, Donihue connected me with Frank Ceci, a 25-year-old Greenwich web developer whose rock wall had recently come to host a lizard colony. Ceci’s parents grew up in Italy, and to Frank’s mother the newly arrived reptiles rang a familiar bell. “She said, ‘They look like the lizards from back home,’” Ceci recalled when I spoke to him over the phone. “I said, ‘Ma, you’re crazy.’”
When Ceci did some online sleuthing, however, he discovered his mother wasn’t crazy after all. In June 2014, he snapped a picture of an Italian wall lizard and posted it to the Facebook page of the state’s Department of Energy and Environmental Protection. The agency’s startled reply: “This is very interesting!”
A few weeks later, Donihue and Lambert traveled to Greenwich for some backyard sampling; over the course of five trips, they captured eight specimens. Future DNA tests should reveal whether the outposts in Greenwich and Hastings-on-Hudson represent offshoots of the New York City population or separate introductions. Though Donihue wants to sample along the MetroNorth corridor, the railroad has, perhaps understandably, proved reluctant to let him wander down the tracks.
Ceci, whose own home lies adjacent to the rail line, is a strong proponent of the MetroNorth dispersal hypothesis; in fact, he posed it himself in his seminal Facebook post. That’s the power of wall lizards — they make non-biologists, yours truly included, turn a more perceptive eye to nature. They cause us to notice, wonder, think. For Ceci, the creatures were an object of scientific inquiry, a source of enchantment, and a node of cultural connection. “We’re really Italian, so it’s perfect that we have Italian lizards,” he told me. “It’s like having a bit of our home country in the backyard.”
Photo by Colin Donihue.
Ben Goldfarb is a freelance journalist whose work has appeared in High Country News, Orion Magazine, and Scientific American.