An icy wind blew across the upper deck of a New York Water Taxi on Jan. 19 as it sped down the East River from the South Street Seaport toward Governors Island, but many aboard braved the cold, eager to see the winter birds of New York harbor.

Greater Scaup. (Photo: Terese Loeb Kreuzer)

New York City Audubon guide Gabriel Willow pointed out some Greater Scaup sheltering along the Governors Island shoreline. This medium-sized diving duck breeds in the Arctic during the summer and spends its winters in New York City and elsewhere along the East Coast. A handsome duck with a blue bill, it finds plenty of food in New York harbor, whose waters are cleaner than they have been in decades.

"There's more wildlife here now than there has been in maybe a 150 years," Willow said.

Amazingly, this city of more than eight million people is a refuge for birds that have flown thousands of miles to get here. Red-breasted mergansers, with what Willow described as their "punk haircuts," also fly down from the Arctic. They breed further north and winter further south than any other American merganser.

Long-tailed ducks, one of Willow's favorites because of their gorgeous plumage, make a similar pilgrimage. These ducks can dive to depths of 200 feet to forage.

The boat pulled into Erie Basin, a part of Red Hook with striking 19th-century warehouses and rusted machinery left over from the days when sugar was processed here, among other industries. Mallards and black ducks cruised beside the pilings along with a few mergansers and buffleheads. Willow hoped to point out some purple sandpipers but there were none to be seen.

He said he hadn't seen any there last winter, either. "Maybe because of Sandy," he mused. But he had seen them recently elsewhere in New York City. They breed in the Arctic tundra and winter along the rocky shores of the Atlantic Coast.

The boat took off again at a good clip, bound for Hoffman and Swinburne Islands - two manmade islands that lie between Staten Island and Brooklyn. They were created in the 19th century to quarantine immigrants coming into the United States by steamship. Those who were merely suspected of having been exposed to disease spent a few weeks on Hoffman Island to see if anything developed. Those who were actually ill were sent to Swinburne. Many of them never left.

Ruins on Swinburne Island. (Photo: Terese Loeb Kreuzer)

Falling into greater ruin year by year, abetted by the harsh winds and waters of Superstorm Sandy, the structures on Swinburne Island once included a hospital and a crematorium. Now the chimney of the crematorium remains, surrounded by cormorant nests.

Swinburne is where the harbor seals like to hang out. As the boat approached, curious, bewhiskered heads bobbed out of the water. Willow said that there are around 20 to 30 harbor seals on Swinburne at this time of the year and around 200 to 300 seals in the five boroughs. He said he had seen them in many parts of New York City.

Harbor seals have been coming to New York for the winter since 2001, said Willow, and maybe longer - but that was when they were first sighted. They need an abundance of fish to sustain themselves. The males can grow to more than six feet long and can weigh around 300 pounds. The females are slightly smaller.

The boat lingered at Swinburne for several minutes so that everyone aboard could see the seals. Then it turned back to Manhattan.

Would the birds and seals be all right in this cold? someone wondered. "Oh, yes," Willow said. "They'll be fine." He said the birds are protected by an undercoat of down with a waterproof topcoat. "A swan," he remarked, "can have 20,000 feathers." Seals are protected by their blubber.

After a largely overcast day, that evening there was a brilliant sunset. Silhouetted against the still-bright sky, flocks of gulls flew over the Hudson River. As ordinary a sight as they are here, a day gazing at wildlife made it clear that there is really nothing ordinary about them at all. Among them were doubtless some travelers whose strength would make the strongest human seem weak. 

(For more information about New York City Audubon/New York Water Taxi harbor tours, see the Calendar section of Downtown Post NYC.)

Ongoing: The National Museum of the American Indian is open daily from 10 a.m. to 5 p.m., with free admission. It offers free films, docent-led tours of its exhibitions and tours of its premises, the Alexander Hamilton U.S. Custom House, designed by Cass Gilbert. The building, which was completed in 1907, is a National Historic Landmark and is listed on the National Register of Historic Places. One Bowling Green. Phone: (212) 514-3700. For the museum's calendar, click here.