At the Harlem Meer, at the north end of Central Park, John Waldman, a biology professor at Queens College, found a bullhead catfish, a newly discovered species for the lake. At Turtle Pond, in the middle of the park, Russell L. Burke, a biology professor at Hofstra University, spied scores of turtles, from red-eared sliders to snapping turtles. And in the North Woods, Glenn Phillips, executive director of New York City Audubon, counted 23 bird species in the first of five forays, among them a Wilson’s warbler and American redstarts, prized fall migrants.
The scientists were part of a team attempting to gauge the variety of plant and animal life in Central Park, whose 843 acres attract far more than homo sapiens, Labrador retrievers and the occasional ferret. For 24 hours, starting on Monday afternoon, a dozen experts in lichens, spiders, birds, fish, reptiles, mammals and flowering plants fanned out across the park in a so-called bioblitz. Through rain and sun and stiff breezes, at dawn and at dusk, they looked under rocks, at trees and in seining nets and, with the help of hundreds of students from the City University of New York, recorded what they found.
It was the first such survey in a decade, and park officials were hopeful that the data would illustrate the benefits of the park’s carefully restored landscapes and water bodies on its biodiversity. “We know that 40 million people enjoy the park every year,” said Doug Blonsky, president of the Central Park Conservancy, the nonprofit group that manages the park for the city. “But how many turtles? How many bats? How many fish? We’re going to have a better idea of just how many different species call Central Park home.”
Those answers will have to wait until later this year, when all the data are compiled — and compared with a similar study a decade ago. But anecdotally at least, the survey yielded a few new surprises. By the 22nd hour, Dr. Burke had counted six species of turtles, the same number as in the earlier study. But after watching a bale of red-eared sliders gliding through the duckweed at Turtle Pond, one of the students noticed a similar-looking turtle, but without telltale red stripes.
“It’s a diamondback terrapin,” Dr. Burke practically crowed, his competitive juices flowing at the sighting of a seventh turtle species. “That’s usually a brackish-water turtle, but it can tolerate freshwater.”
The birding expeditions were also fruitful. Mr. Phillips reacted positively to the Wilson’s warbler, a plump yellow bird with a black cap, flitting about in the North Woods. “That’s our highlight, for sure,” he said.
For the students, who are enrolled in CUNY’s Macaulay Honors College, the outings were a lesson that New York City is not all limestone and mortar. Most conceded that their knowledge of urban birds was limited to pigeons. “There are beautiful things in the city, and you don’t have to travel halfway around the world to find them,” said Aleksandra Mikhaylova, 20, of Brooklyn.
The students tapped the expertise of scientists based at institutions as varied as the American Museum of Natural History, the New York Botanical Garden and Columbia University. In the coming months, the Central Park Conservancy and Macaulay Honors College plan to create programs based on the data collected during the survey.
“The bioblitz has both a scientific and educational purpose,” Mary C. Pearl, the college’s associate dean and chief academic officer, said.
Whether weeding out invasive plant species and cleaning up water bodies has lured more species is uncertain, however. Some of the animals that thrive in the park are pet-store castoffs, like the nonnative red-eared sliders, which are the most abundant turtles in the park. According to Dr. Burke, the sliders pose no known threat to the two native turtle species in the park, the Eastern painted turtle and the snapping turtle. Pointing to a slider that was contentedly basking on the edge of the Reservoir, he said: “This was probably released by someone who realized that water turtles make lousy pets. They get big, need a lot of space, and smell.”
And how did the bullhead catfish make its debut in the Harlem Meer, an oblong man-made lake? Dr. Waldman, author of “Heartbeats in the Muck: the History, Sea Life and Environment of New York Harbor,” said that the Meer was stocked with fish in past years and that the bullhead catfish was most likely there all along. “There are a lot of cryptic species under our noses, and sometimes we don’t notice them until we look,” he said. “That’s the value of a bioblitz.”
Still, he said the presence of bluegill sunfish, pumpkinseed sunfish, black crappie, largemouth bass, golden shiner, catfish and other species in the Meer and lakes in the park was a positive sign. “You have nice species diversity and different age classes and high abundance,” he said. “You could take these ponds and put them in the Catskills and they wouldn’t be out of place. Considering where they are, these water bodies are quite impressive.”