North Brother and South Brother Island natural areas

The 31-acre North Brother and South Brother Harbor Heron Islands are part of the Harbor Herons Region, a national recognized complex of uninhabited islands and expansive marshes essential for shorebirds, located right here in New York City. Gulls, herons, cormorants, ibises, and egrets prefer the seclusion of islands for nesting and rearing their young. They congregate at South Brother in the East River, and at several islands off Staten Island and in Jamaica Bay every spring.

These birds have been the focus of extensive research, as their numbers fluctuate significantly between years and locations. However, even keeping these fluctuations in mind, the decline in number of birds in the New York Harbor is a source of significant concern for regional conservation biologists. While the numbers of great egrets and snowy egrets are holding steady or slightly increasing, black-crowned night heron and glossy ibis numbers are decreasing. The decline of the glossy ibis, a less abundant species locally, is less concerning because it had only recently expanded its historical range to include New York City. Black-crowned night herons, on the other hand, are in danger of disappearing from NYC by 2035 if current trends continue. NYC Bird Alliance, Parks staff, and many dedicated volunteers visit and count the number of nests, eggs, and/or baby birds at South Brother and the other Harbor Heron Islands. In order to gain an understanding of the population dynamics of these birds, data is shared and analyzed among scientists throughout the region.