Although eagles are quite easy to spot, it takes a careful scan with binoculars or a spotting scope to find harbor seals. They are few in number, and appear as nondescript, nearly motionless dark shapes against the white of the ice. They are usually sleeping off a meal of Hudson River fish. In the open leads among the floes will be rafts of diving ducks. The most impressive rafts often consist of scaup and the regal canvasbacks.
Male canvasbacks are especially handsome with their reddish heads and clean white bodies.
American goldeneye, buffleheads, and mergansers are also numerous, and ruddy ducks and ring-necked ducks may be sprinkled among them. It is often enough just to stand along the river's edge and watch and listen to the ice drift past. In its groans, moans, and screeches, one can sense the power and energy of the entire watershed. A phenomenon that I never tire of watching as the tide turns in the estuary is the inshore ice flowing in one direction while the mid-river ice flows in the other. However, this ice show can be ephemeral.