Another Sign of Winter – The Atlantic Brant are Back

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Written By Joe Reynolds
New York Harbor Nature Blog

​Since October small flocks of Atlantic brant (Branta bernicla hrota) have been flying in one by one. Flocks of fifty birds or less have just kept coming into New York Harbor and surrounding estuarine areas to stay throughout the winter. An abundant population of brant into the hundreds or even thousands now calls New York Harbor home for the winter.
 
A majority of brant will over-winter along the coast of New Jersey and the southern shore of Long Island including within New York Harbor.  Lesser numbers of brant will winter north to Massachusetts and south to Chesapeake Bay and North Carolina.
 
With large numbers of brant starting to settle in, the arrival of winter is not far behind. Like the first sight of a White-throated sparrow near your bird feeder, the arrival of brant to New York Harbor is a sure sign that there is a change in the season taking place. 

​Brant arrive to New York Harbor to spend the winter in a warmer place from where their breeding sites are located.  Brant nest in wet areas along the high Arctic coastline around the Foxe Basin in the eastern Arctic, including on Southampton (along the Bell Peninsula and around East Bay), western Baffin (Cape Dominion), Prince Charles, and North Spicer Islands. Every fall, the brant arrive to New York Harbor to escape thick ice up north, which covers over their aquatic food. 

​Now I know what you are saying. Why should anyone get excited about more geese from Canada? But brant are not Canadian geese. While brant are a member of the goose family and tend to be similarly colored to a Canada goose, brant are smaller in size. They are in fact the smallest goose of the goose family. They are about two feet in length with a dark brown or black head, neck and chest and a white band on the neck.
 
Brant are also not attracted to eating grass, especially at golf courses or playgrounds. Their favorite foods all tend to be aquatic vegetation. Many flocks spend the winter months grazing within the shallows of protected bays and inlets to feed on eelgrass, sea lettuce and green algae.
 
Whereas many Canada geese remain here year-round, brant are true migratory birds. They frequently fly over 2,000 miles from their nesting grounds in the tundra on the coast of Arctic Ocean to over-wintering sites. 
 
During fall migration, brant will depart their arctic breeding grounds to fly along the eastern shore of James Bay, north of Rupert Bay. The birds will remain at this place for some time to rest and refuel before taking a direct flight path between James Bay and over-wintering sites along the eastern Atlantic Coast.  No other geese nests as far north as the brant, and few migrate as far.
 
For me, Atlantic brant are jut fun to watch in the winter. For starters, they are highly gregarious. You will rarely just see one brant. They are also one of the most vocal waterfowl in New York Harbor. Brant can often be heard before ever being seen. They are seldom quiet and make a loud mellow "cronk" sound that can regularly be heard in flight and when foraging for food.
 
Brant will forage in flocks for sea grasses by wading or tipping up in shallow water. As food supplies move around by winds, tides, currents, and coastal storms, so do brant, seeking a delicious seaweed salad miles from where the brant might have been feeding the day before. As a result, prolonged, severe cold temperatures can move brant further south to seek out a meal.

​Unfortunately, all is not well with the Atlantic brant population. Scientists with the University of Delaware have been finding that the Atlantic brant population has been fluctuating and are on a moderate decline. Over the last several years, biologists have seen that in winter surveys of Atlantic brant in the Mid-Atlantic, there are few young in the population, indicating that something could be going drastically wrong for nesting brant on their Arctic breeding grounds.
 
Studies suggest that populations of Snow geese and Cackling geese have rapidly increased in the last 20 years due to the lack of natural predators in some areas of North America and improved food supply from forested land being converted to agriculture. These two species of geese are gradually pushing brant to the margins.
 
When brant are forced to nest farther away from the water in lower quality sites due to competition, they are vulnerable to predators, including Arctic foxes, herring gulls and parasitic jaegers, that prey on their nests during incubation or incubation breaks when adult brant leave their nests to forage. The predators are potentially drawn to the nesting areas because of the influx of Snow and Cackling geese. These predators might normally only affect the brant in low levels, but if high densities of Cackling geese or Snow geese draw these predators in, then the brant may be suffering secondarily as a result of it. 
 
Sadly, for the brant declining populations is nothing new. Their population seems to be on a roller coaster for the past century. In the early 1930's, brant went into a severe population decline when a disease wiped out nearly all of the Atlantic Coast's eelgrass, which up to that time had made up about 80 percent of the birds' diet. Slowly the birds rebounded by turning to other food sources for their survival. Brant switched to sea lettuce and other marine algae, which had always been part of their diet, but in small quantities. Eventually the eelgrass recovered and the brant population recovered as well.
 
New threats today are still disturbing Overall, Atlantic brant numbers are on the decrease. So it will be interesting to discover if we see more or less brant this winter season than we have in the past around New York Harbor. The big question is – how long can this small sea goose continue to take a long winged migration to the edge of the planet to raise a family and then take another long winged journey to over-winter along urban-suburban waters in East Coast of America as the planet continues to warm before the entire population collapses?  Never a dull moment in the natural world.