Thousands of Northern gannets seen in Sandy Hook Bay on Monday morning. They were plunge-diving high in the sky to catch a fish (herring) in New York Harbor. An amazing natural sight not to be missed during early spring.
It was a rain soaked Friday when I took an afternoon Seastreak ferry from downtown Manhattan to Highlands, NJ to head home. As the large double-hulled catamaran started streaming into Sandy Hook Bay there was something unusually organic taking place outside my window not far from the entrance to New York Harbor.
There were several dozen large bright white birds with long black-tipped wings resting on the water among the wild and choppy waves. These were tough pelagic seabirds, well adapted to the marine environment. Resting in the rain and wind was just another day.
The sight left no doubt in my mind - Northern gannets have returned to New York Harbor. They have retuned from the open ocean to feed before migrating north to breed. It’s a natural wonder that has been taking place for countless years during early spring.
To some people, it might come as a surprise to learn New York Harbor has Northern gannets. But the birds come here by the thousands to feed on rich coastal-estuarine aquatic resources. Gannets feed mainly on small schooling fish about one to two inches long. This includes herring, sand lance or sand eels, and menhaden or bunker. These forage fish fuel many natural activities in the bay.
During the winter, Northern gannets will take a break from the previous busy breeding season to spread out. They will fly and fish their way down the Atlantic Ocean, generally following the length of the continental shelf from New England to Florida.
Gannets are nearly always seen near Lower New York Bay, the south shore of Long Island and down the Jersey Shore. Author William J. Boyle Jr., in the book, The Birds of New Jersey, tell us that nearly 17,000 Northern gannets were spotted on a single day in 2009 at the Avalon Sea Watch site in New Jersey between November and early December. The seabirds fly free form in search of food.
Come early April, gannets will gather around New York Harbor often in large flocks as they begin to migrate northward to start another busy breeding season. The seabirds can be spotted soaring high above local tidal waters in pursuit of fish.
At times the sight of gannets feeding can be exciting and entertaining. Gannets fly higher than other seabirds, about 100 feet or more above the water’s surface, and will plunge-dive steeply into chilly water, head first, with wings folded against the body just before entering the water to make almost no splash to catch a fish among a large bait ball. Even from a distance, the sight of many gannets plunge-diving into the water is electrifying, like a blizzard of large white birds diving in at the same time as others emerge from cold waters below.
But the sight does not last long, sometimes a few days or weeks. The gannets will soon be heading to breeding sites mainly in the Gulf of St. Lawrence and off the coast of Newfoundland. The Cornell Lab of Ornithology states there are six primary nesting colonies in this area: three in the Gulf of St. Lawrence, Québec, and three in the North Atlantic off the coast of Newfoundland. Along the south coast of Québec, Bonaventure Island has the largest nesting colony with around 32,000 nests. It's also a favorite tourist destination for people to observe the spectacle of nesting gannets.
Other nesting colonies can be found scattered along rocky sea cliffs or on remote islands of Iceland, Ireland, France, and northward to Norway and Scotland. For example, the mile-long cliffs at Noss National Nature Reserve in Shetland are home to 150,000 Northern gannets.
During the summer, Northern Gannets will breed on well-established, tightly packed colonially breeding areas. They will raise just one chick per year, no more. If a pair loses its chick to sickness or predation, that's it. The breeding season is a stressful time for parents. They need to vigilantly care for its solitary offspring.
Threats to Northern gannets include oil spills, water pollution, and global warming, which can diminish fish stocks and cause food shortages. Thankfully, the global population of gannets seems to be doing well so far. Many international wildlife organizations, including the International Union for Conservation of Nature, claim the population is widely distributed and appears to be stable or increasing.
So get out now and enjoy the spectacular sight of Northern gannets hunting for food in New York Harbor. Trust me, the sight is short-lived. One day they are here by the thousands, and the next day nothing. The birds are refueling quickly to migrate to nesting colonies up north to raise the next generation of tough pelagic seabirds.