Video
Treasure Islands
New York City Audubon’s Harbor Herons Program aims to protect a thriving community of water birds in the city’s surrounding wetlands.
By Katherine Bagley

Click on the image above for a video of New York City Audubon’s efforts to preserve waterbird habitat.

Worn tires, pillars of driftwood, and cracked buoys clutter the smooth stone beaches of South Brother Island, an abandoned and nearly forgotten chunk of land nestled in New York City’s congested East River. Across the water, just a thousand feet away, the spiked stone watchtowers at Rikers Island prison loom, and the smell of stale, baked bird guano hangs in the heavy summer air. Thick oriental bittersweet vines tangle tightly around the branches of locust and mulberry trees, obscuring what Susan Elbin, director of conservation for New York City Audubon, came to see. “They’re a bit rattled today,” she says as a chorus of low, throaty calls echoes through the trees. The sun beats down through cracks in the forest’s woven branches, and Elbin wipes away sweat rolling down her tan, creased face with the back of her arm, pushing aside dark blond bangs. She adjusts her binoculars to focus on two great egrets facing each other on a branch, their white wings aggressively spread wide and their necks outstretched. “Beautiful though, aren’t they?” 

Until about a century ago South Brother was the summer home of one of New York’s wealthiest families. But after a fire destroyed the home in the early 1900s, the island was essentially abandoned, and nature gradually reclaimed the land. Unmarred by roads, power lines, or buildings, South Brother’s isolation from the city’s hustle and bustle makes it a perfect oasis for hundreds of breeding egrets, herons, ibises, and other birds. New York City Audubon is trying to keep it that way through its Harbor Herons Program, which works to preserve the breeding and foraging grounds of various colonial water birds. Since 1984 chapter members have been surveying nests and monitoring the birds’ health, lobbying for wetland protection, and conducting community outreach and education to raise awareness of avian harbor species.

The program encompasses 19 sites scattered throughout the harbor. Of those, South Brother is the crown jewel, hosting the most nests (592 in 2007) of any other island or marshland. The city finally acquired the seven-acre islet, the last privately owned island in New York harbor, in 2007 after a complex $2 million deal financed with federal money secured by Representative José Serrano, organized by Bronx-based nonprofit organizations The Point and the Wildlife Conservation Society, and brokered by the Trust for Public Land. Following the purchase, the city’s parks department designated the island a Forever Wild habitat (there are more than 50 such preserves in the city’s five boroughs), ensuring its protection from future development.

New York City hasn’t always been a safe haven for birds. During the late 19th century a fashion craze for feathered hats left egrets nearly extinct in the region. For decades pollution, wetland degradation, and land development forced many other species from the area as well. It wasn’t until after the Clean Water Act of 1972 and subsequent water-quality improvements that the harbor birds gradually began to move back into the area, first to Staten Island’s Arthur Kill wetlands and later to marshes and islands stretching from Long Island to New Jersey, the majority of which are now protected by local, state, or federal conservation agencies. In 2007 nearly 2,000 active nests were counted within the harbor, representing black-crowned night-herons, great egrets, snowy egrets, glossy ibises, yellow-crowned night-herons, little blue herons, tricolored herons, cattle egrets, and green herons.

These environmental regulations and habitat protection have helped lure birds back to the city, but water bird colonies are still threatened, particularly by development and trespassers. When conducting research on South Brother, Elbin, along with Kate Ruskin, the coordinator of the Harbor Heron Project’s citizen scientist program, carry a large, fanned folder stuffed with city- and state-issued permits, but urban explorers often trek illegally through the nesting sites, enticed by the thrill of venturing onto highly restricted property or to get a taste of history. (The South Brother house that burned down was owned by Jacob Ruppert, a brewery magnate and later owner of the New York Yankees; rumor has it that Babe Ruth hit balls into the East River from Ruppert’s lawn before the fire.) Researchers often find ashes from recent campfires and fresh garbage in the woods. A few years ago geocache adventurers—they hunt for treasure with GPS devices—even hid a target on the island.

There has also been talk of making South Brother and its sibling, North Brother, publicly accessible. According to a 2008 article in the New York Daily News, advocates have tried to add both islands to the Gateway National Recreation Area, a string of urban parks in the New York metropolitan area that get an estimated 10 million guests a year. “I understand why groups would want to open up the islands to visitors,” says Elbin. “They are fascinating places, and we always want people to be able to experience New York’s wildlife. But the birds need safe areas to loaf, or rest, and breed if they are going to remain in the harbor. Visits would have to be tightly controlled and timed around breeding seasons.” During the past few seasons birds have already stopped reproducing on North Brother, home to an abandoned, crumbling infectious disease hospital that attracts trespassers because of its eerie mystic. Elbin is afraid the foot traffic disrupted the birds’ breeding cycles or made them feel threatened.

Perhaps the greatest threat to the birds isn’t disturbance to their nesting sites or threats of public access, however, but destruction of their foraging grounds. According to PlanNYC, an initiative to create a more sustainable future in New York, the city has lost 99 percent of its historic freshwater wetlands and about 90 percent of its tidal wetlands. As human population and development pressures grow, these precious slices of habitat continue to shrink by an average of 20 acres per year. Furthermore, New York State laws don’t regulate or protect previously unmapped wetlands or sites smaller than 12.5 acres—spots that New York City Audubon believes are critical feeding grounds for city’s herons, egrets, and ibises.

The Harbor Herons Project recently launched a study to find out where the water birds are searching for food in an effort to drive wetland conservation in the New York City-New Jersey region. “If the birds can’t sustain themselves, they aren’t going to breed here anymore,” says Elbin. The research is focusing on great egrets, “because they’re large, mega-charismatic, gorgeous birds,” says Elbin—but its results will offer insight into the status of the food chain as it relates to other harbor heron species as well.

This study is what has drawn Elbin and Ruskin to South Brother in late July. As part of the effort, researchers and citizen scientists from New York City and New Jersey Audubon chapters have been mapping the harbor birds’ movements between nesting and foraging grounds using a combination of radio transmitters and color bands. The project has radio-tagged nine egrets so far—six on South Brother and three on Hoffman Island, off Staten Island. Each tag is attached to an egret’s leg and has its own unique frequency that will be checked every hour by a transmitter. If the device detects a particular bird’s frequency, the individual is recorded as being present on the island.

Six feet up a tree, Ruskin struggles to strap the large radio antenna onto a branch, her green Wellington boots scraping against the bark. Meanwhile, Elbin tucks a faded blue Coleman cooler housing the radio transmitter recording equipment into a tangle of vines. A cluster of double-crested cormorants huddle just offshore, their shrill, coughing call temporarily masking the droning sounds of gulls and egrets. “One question this radio technology can help us answer is, What is the post-fledging dispersal of these birds?” says Elbin. “When do they stop using the island? Do they use it for their first hatching year until they migrate? We don’t know, but this will help us figure it out.”

Conducting research in New York City can be difficult, particularly when dealing with radio telemetry systems. Because South Brother Island lies in the direct flight path of LaGuardia Airport, jets flying overhead often flood all of the radio signals nearby and overload Audubon’s transmitter system, disrupting the final count of tagged egrets on the island. “The number of presences we have is actually an underestimate,” says Ruskin. “When [the transmitter] gets overwhelmed by interference, it records an absence even though a tagged bird could be standing right next to it.”   

In a few weeks Elbin and Ruskin will move the system to a new location—marshland in New Jersey, Staten Island, Jamaica Bay, Brooklyn, or Queens—and once again record the presence of their tagged birds. At the end of the project, Audubon researchers will combine records of bird sightings submitted by citizen scientists with data from the radio transmitters in order to map out which marshlands the egrets from South Brother and Hoffman Island are foraging in. They hope that the information will help them protect not only the birds’ nesting grounds but their food sources as well.

Once the antenna is secure and the transmitter working, Ruskin and Elbin head for the beach to search for any gull eggs laid late in the breeding season. In front of them, Manhattan’s skyline rises in the distance veiled by a hazy cloud while the cries of egrets emanate from the forest behind—reminders that New York is not only a hub for culture and business, but wildlife as well, even in the smallest of protected spaces.

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