Ants of New York





On a recent Monday, Savage and a biologist named Clint Penick found themselves knee-deep in the bushes of Broadway, where they had climbed into a median just south of Lincoln Center. Penick, who is thirty-one, wrote his first scientific paper using research from his Florida back yard; in eighth grade, he played guitar in a band called the Army Ants. (“It was my middle-school mind’s version of what a punk band should be called,” he said.) He can identify some ants by smell. One species in the southern U.S. has an alarm pheromone that smells like chocolate, he said, though “you have to crush their heads to smell it,” and one New York ant smells like citronella. Another, which he helped a non-scientist friend to identify at her Brooklyn apartment, is known as the “odorous house ant,” and smells like blue cheese.

A security guard stopped by to ask Penick if he had a permit. The guard called his manager—“It’s the same thing they were doing last year. Yeah, I remember them”—then left Savage and Penick to turn their attention groundward. The pair sifted clumps of dirt from beside tree trunks, beneath rocks, and under the occasional cinderblock, and found two flat, ant-heavy spots to set up feeding trials. Previous visits had determined that street ants thrive on food scraps that people toss away. This round of study offered the ants oils and food scraps alongside more traditional insect prey—crickets, mostly—to see whether median ants prefer complex fats and oils, such as olive oil, to those found in processed foods. (They still prefer crickets, but of the oils they seem to express a very slight preference for the olive oil, which is most similar to the fats in their natural prey.) Savage and Penick laid out their materials where they found most of their ants, near the pedestrian crosswalks. “Ants like to live under cracks in the pavement, so they live at the edges of the medians,” Penick said. “Also, the ends are closer to the garbage cans.”

Broadway doesn’t always provide ideal lab conditions. In addition to the occasional run-in with a diligent security guard, Penick and Savage have had to sidestep landscapers and watering trucks, and once wasted a good part of a research day before realizing that a crew of groundskeepers had been trailing them from median to median, lagging a few blocks behind, and tossing out their experiments. “Another time, it was pretty clear that a rat had chewed the olive-oil tube,” Savage said.

Beyond any implications for ant ecology, Savage hopes that her work on Broadway will help to recalibrate a field whose models are still cloaked in their tropical origins. Much of what scientists learn about ecosystems still tends to be applied to the kinds of isolated settings that some researchers describe as “islands” of wildlife within a “sea” of agriculture, where the human impact on plant and animal life seems more indirect. “Understanding cities is going to help ecologists move forward and understand big ecological questions in a better, more thorough way,” Savage said. “You have to add people back in.”