Large Raft of Bluebills in the Navesink River

​New York Harbor is always full of surprises, especially when it comes to viewing wildlife. Between the bustle and buzz on roadways and in waterways can be found some excellent examples of wild animals using our urban environment for their advantage.
 
Last week, a good number of marine diving ducks, known as scaup or bluebills, were taking advantage of tranquil tidal waters in the Navesink River, near the southern shore of New York Harbor, to rest and feed on sea lettuce. A quick count had well over 1,000 birds, a huge raft that stretched out into two long columns creating nearly a ‘t” shape in the open water.

​Authors Chris C. Fisher and Andy Bezener in their book, Birds of New York City, describe males as looking like an “Oreo cookie,” a bird with largely black feathers on the ends and white feathers in the mid-section. Females have mostly chestnut brown feathers. Both male and female birds are diving ducks with unique looking bluish bills. 
 
Two scaup species can be found swimming in New York Harbor: the Greater Scaup and the Lesser Scaup. Both species look similar. The Greater Scaup has a more rounded head and the Lesser Scaup has a narrower bill. The Lesser Scaup is also one of the most abundant and widespread of the diving ducks in North America. 

​Both species of scaup are generally seen as winter residents around New York Harbor. These diving ducks are frequent visitors to the harbor every winter. Sometimes flocks are small, but some years, especially when inland lakes freeze over, the ducks will come together in large numbers. Author William J. Boyle Jr. in his book, The Birds of New Jersey, tell us that “mid-winter counts of 50,000 on Raritan Bay have been recorded on several occasions” for Greater Scaup.
 
The birds migrate to New York Harbor for two reasons – large areas of open water and the abundance of aquatic food, including clams, mussels, snails and sea lettuce. They spend about five months or so in the harbor to rest and feed before flying off to begin another busy breeding season.
 
Greater Scaup nest mostly on lakes and bogs near the northern limits of the boreal forest in Canada. Lesser Scaup will breed farther south, from the tundra into the Great Plains of the United States on marsh ponds. 
 
Enjoy the sight now of seeing these delightful diving ducks, because soon they will be away on their long winged migration. Scaup will keep swimming and feeding until they have their fill, then they fly away not to be seen until next winter.