William E. Macaulay Honors College found 571 total species, including 173 species that were not previously known to live there. Flora , Central Park had more than 20,000 trees, representing a decrease from the 26,000 trees that were recorded in the park in 1993. The majority of them are native to New York City, but there are several clusters of non-native species. With few exceptions, the trees in Central Park were mostly planted or placed manually. Over four million trees, shrubs, and plants representing approximately 1,500 species were planted or imported to the park. In Central Park's earliest years, two plant nurseries were maintained within the park boundaries: a demolished nursery near the Arsenal, and the still-extant Conservatory Garden. Central Park Conservancy later took over regular maintenance of the park's flora, allocating gardeners to one of 49 "zones" for maintenance purposes. Central Park contains ten "great tree" clusters that are specially recognized by NYC Parks. These include four individual American Elms and one American Elm grove; the 600 pine trees in the Arthur Ross Pinetum; a Black Tupelo in the Ramble; 35 Yoshino Cherries on the east side of the Onassis Reservoir; one of the park's oldest London Plane trees at 96th Street; and an Evodia at Heckscher Playground. The American Elms in Central Park are the largest remaining stands in the Northeastern United States, protected by their isolation from the Dutch elm disease that devastated the tree throughout its native range. There are several "tree walks" that run through Central Park. Fauna Central Park contains various migratory birds during their spring and fall migration on the Atlantic Flyway. The first official list of birds observed in Central Park, which numbered 235 species, was published in Forest and Stream in 1886 by Augustus G. Paine Jr. and Lewis B. Woodruff. Overall, 303 bird species have been seen in the park since the first official list of records was published, and an estimated 200 species are spotted every season. No single group is responsible for tracking Central Park's bird species. Some of the more famous birds include a male red-tailed hawk called Pale Male, who made his perch on an apartment building overlooking Central Park in 1991. A mandarin duck nicknamed Mandarin Patinkin received international media attention in late 2018 and early 2019 due to its colorful appearance and the species' presence outside its native range in East Asia. Another bird,