Northern right whales are black with variable gray patches on their throats and bellies. The flippers are short and very broad. Tough cornified white skin patches, called callosities, are used with other markings to identify individuals. Callosities are located on the top of the head, above the eye, behind the blowholes, and along the lower jaw. These areas of callused skin begin to develop soon after birth and are observed on very young right whales.
Sparse hair appears in the tips of the chin and upper jaw, often associated with callosities.
Large amounts of blubber, about two-fifths its body weight, give the right whale a particularly rotund appearance. Northern right whales have been sighted from Iceland to Florida, but the only known calving area is the coastal waters of Georgia and Florida. Peak abundance of right whales in this area, as well as calving, occurs from December through March. In March and April, right whales congregate in the plankton-rich waters of Cape Cod Bay, the Great South Channel, and Georges Bank off Massachusetts to stock up on much needed nutrients. These whales continue their northward travels to breeding and feeding grounds in the Bay of Fundy and off the southeastern coast of Nova Scotia where they spend the summer and fall.