October is Bat Awareness Month, making this the perfect time to share the results of a new study revealing that these mysterious and misunderstood creatures are at the center of summer nightlife on the High Line.

As fanged, flying critters of the night, bats can have a bad reputation—wrongly reviled as pests and appreciated mostly as spooky symbols of Halloween. In fact, bats are among nature’s most essential workers. They pollinate plants, disperse seeds to support forestation, and protect crops and reduce the use of chemical pesticides by consuming copious amounts of moths, beetles, and other insects.

However, of the 40 species of bats in the United States—there are 1,500 species worldwide—half are in severe decline or endangered. That’s why the High Line is thrilled to announce the results of our 2025 High Line Bat Survey. Conducted by Nic Comparato, a PhD student at Rutgers University and founder of the Urban Bat Project NYC, between August 21 – September 6, the survey found that the High Line was one of New York City’s hottest hangouts for bats during their late summer migration.

Surveys on the High Line were conducted using a passive acoustic bat detector, a device capable of detecting and recording the process of echolocation—a sound-based system bats use to navigate and hunt at night. Through echolocation, bats send out high-pitched, ultrasonic sounds—sonar—and then interpret the resulting echoes for information about their surroundings. Echolocation is well outside our human range of hearing, but bat scientists (or chiropterists) can use graphs known as spectrograms, which create visual images of each recorded sonar pulse, to analyze bat activity and identify species.

A spectrogram shows the sonar pulses of an eastern red tail bat on the High Line.Photo by Nic Comparato

The High Line’s bat detector found that the dominant bat species on the High Line was the eastern red bat, a common migrator in the United States, with flexible foraging habits that make it well-suited for surviving in cities. According to the survey, 59 eastern red bats were identified on the High Line on August 21. The population ebbed and flowed quite dramatically over the next week, before surging to a peak of 74 bats on August 30. By the following evening, it was time to fly the coop. Their numbers had dropped to 19, and only four red bats remained by September 6.

While this species is a known city-dweller, researchers were fascinated to find that they were particularly at home on the High Line’s 23rd Street Lawn. The echolocation recordings documented the bats convening there in clusters—settling in for sociable banquets of insects, rather than just a quick fly-by, making it a “valuable migration stop” according to their report. They were also surprised by how closely the bats interacted with the habitat and by the number of “feeding buzzes”—unique sounds bats make while consuming insects—captured in the recordings, indicating successful foraging.

“The High Line is in a heavily developed area of Manhattan with sparse resources for migrating bats,” said Comparato. “I wasn’t sure what to expect, but the activity levels I recorded at the 23rd Street Lawn really surprised me. The lawn appears to be a valuable stopover for hungry bats as they prepare for the next leg of their migratory journey.”

Even more surprising was the discovery that the High Line was also visited by hoary bats, a much less common migratory bat in the United States that is quite specific in its stopover habitat requirements. Hoary bats typically favor large parks with tall solitary trees, and Camparato had not expected to see more than a handful of hoary bats during the survey. The documented presence of multiple hoary bats per night—peaking at 8 on September 6—was quite the plot twist. Another mystery was the conspicuous absence of the big brown bat. This species typically thrives in urban environments, but its habitat choices and behaviors in New York City remain enigmatic. All of this has intrigued researchers to learn more about the High Line’s appeal to bats.

“I’ve long suspected that the gardens of the High Line provide food and shelter to a wide variety of animals, and this survey confirms that bats are among those animals,” said Richard Hayden, Senior Director of Horticulture for the High Line. “However, I was completely surprised at the level of bat observations and the rather rare detection of the hoary bats that were identified. Bats are an important species in the web of nature. They control insect pest populations, and have even been noted to eat our invasive spotted lantern flies. While this was a brief, late-season survey that identified bats migrating south for the winter, we are very much looking forward to doing more bat survey work next year and expanding our research to include community science opportunities.”

An Eastern red bat hangs from a tree on the High Line.Photo by Rowa Lee

Here are some more fascinating facts about bats:

• Bats are mammals—they are covered in fur, give birth to live babies, and nurse their young with milk. Baby bats are called pups.
• Bats are the only mammals capable of flight.
• Bat “wings” are actually hand structures with skin stretched between elongated fingers, which is how bats get their Latin name, Chiroptera, or “hand-wing”.
• The fastest mammal on earth is not the cheetah, but the Mexican free-tail bat, which has been clocked flying at speeds of 100 miles per hour.
• Bats are not blind. They have keen, low-light vision.
• Bats comprise one quarter of the Earth’s mammal population.
• Bats can consume up to 1,200 mosquitoes per hour and often consume their body weight in insects per night.
• Nocturnal bats detect insects to eat in the dark by emitting rapid sounds inaudible to the human ear and listening for an echo—a process known as echolocation.
• Bats can be big. The Flying Fox bat of the South Pacific has a wingspan of six feet.
• Bats can be tiny. Thailand’s bumblebee bat is the size of a thumbnail.
• Some bats hibernate in caves over the winter—and some can survive being encased in ice.
• Neither rodent nor bird, bats are more closely related to primates and whales.
• Bat droppings, called guano, are one of the world’s richest fertilizers. Prior to oil, guano was actually the state of Texas’ largest mineral export.