The Dance of the Mergansers
by Dan North
The human hand lies heavy on the landscape of Newark Bay. From where I stand in Bayonne's Rutkowski Park on the Bay's eastern shore, giant container ships and gantry cranes at Port Newark, the nation's third busiest seaport, dominate the opposite shore. Above me roar some of the 65,000 vehicles that cross the New Jersey Turnpike's Newark Bay Bridge each day. Low in the sky zoom planes which carry 43 million passengers each year to and from Newark Liberty International Airport. Behind me rise the uniform red brick buildings of a housing development.
I'm standing this winter morning on a raised wooden walkway that wanders through a small marshy Newark Bay inlet on the edge of the storied Hackensack meadows. Discarded soda bottles and clumps of pebbly white Styrofoam litter the mud below the walkway. The mud is contaminated with toxic chemicals from Newark's industrial past, including PCBs, heavy metals and cancer-producing dioxin released for decades into the nearby Passaic River from what is now the Diamond Shamrock federal Superfund site. Crabbing is illegal here, fishing strictly limited and swimming unthinkable. But the sea birds that winter here don't know this, and it's them I've come to see. I aim my binoculars above an empty cardboard six-pack container lodged in the cord grass and focus on the open water of the inlet. A small flock of wigeons comes into view, identifiable by the males' crown-to-bill white stripe. An elegant black and white bufflehead dives and re-appears, a cormorant on a rocky hummock dries its spread wings and a small raft of canvasbacks appears in the distance. Then, from around a small peninsula to the north, swims one of my favorite birds - a red-breasted merganser. This easily identified diving duck's tousled, disheveled crest makes it look like it's just gotten out of bed. The breeding male is colored a handsome mix of red, white and green. Its pencil thin beak has serrated edges to better grasp small fish.
I often see red-breasted mergansers diving alone or in groups of two or three in New York Harbor. But today is different. As I watch the first merganser paddle into sight, more follow. Eventually nearly two dozen are swimming in tight formation from right to left across the narrow inlet. They're excited; some rise halfway out of the water and flap their wings, others scoot ahead with a feverish half-flapping half-swimming motion. And then the unexpected happens. As if directed by an Esther Williams water ballet choreographer, they all dive at once. The inlet's surface is eerily still for 15 or 20 seconds until the mergansers pop up in unison and resume swimming southward. They repeat this synchronized performance several times until they reach the inlet's southern edge. There they turn and duplicate the routine in the opposite direction until they disappear around the point from which they came. I feel like applauding.
At home that night I consult "The Birder's Handbook" and find that red-breasted mergansers are "known to fish in [a] cooperative manner to drive fish into shallow water." A quick Google search produces the same observation. There is no mention of similar behavior by the related common and hooded mergansers. So, I think, hundreds of thousands of years ago, maybe millions, the quirky hand of natural selection dealt this particular creature the gift of cooperation. Among the places this adaptation must have developed was Newark Bay, here where the Hackensack and Passaic Rivers join before their journey through Kill Van Kull, New York harbor and the Narrows into the open Atlantic.
Mergansers were diving together here long before today's diesel fumes, tank farms and garbage dumps. They were here many millennia before landfill reduced the Hackensack meadowlands to half their original size and invasive phragmites crowded out native reeds. Mergansers dove here long before industrialization brought paint, varnish, hat, leather, jewelry, fertilizer, defoliant and pesticide factories to the Passaic's Newark shore. They fished these shallows eons before the New York, Philadelphia and Washington 19th century vacationing aristocracy swam and sailed from the 200-room colonnaded, turreted, flag-bedecked La Tourette Hotel on Bayonne's Newark Bay shoreline. Mergansers wintered here long before the Native Americans, Dutch and English discovered this then-pristine bay. Now, as our carbon emissions begin to further transform the planet in unimaginable ways, mergansers still dive together here. Seeing them is a gift that no amount of plastic bags flapping in the stunted bayside willows can spoil, and I'll take it.
