North Atlantic right whale mother and calf

The North Atlantic right whale (Eubalaena glacialis which meant "good, or true, whale of the ice,") is a baleen whale, one of three right whale species belonging to the genus Eubalaena, which was formerly classified as a single species. About four hundred North Atlantic right whales live in the North Atlantic Ocean.

They migrate between feeding grounds in the Gulf of Maine and wintering sojourn and calving areas in Georgia and Florida. This is an ocean area with heavy shipping traffic.

Like other right whales, the North Atlantic right whale is readily distinguished from other whales by the callosities on its head, a broad back without a dorsal fin, and a long arching mouth that begins above the eye. The body of the whale is very dark grey or black, occasionally with some white patches on the belly. The right whale's callosities appear white, not due to skin pigmentation, but to large colonies of cyamids or whale lice.

Adult right whales average 35–55 feet (11–17 m) in length and weigh up to seventy tons (63,500 kg); the largest measured specimens have been 60 feet (18 m) long and 117 tons (106,500 kg). Females are larger than males and first give birth at age nine or ten after a year-long gestation; the interval between births seems to have increased in recent years and now averages three to six years. Calves are 13–15 feet (4.0–4.6 m) long at birth. There is little data on their life span, but it is believed to be at least fifty years, and some may live more than a century.

Source: Wikipedia (All text is available under the terms of the GNU Free Documentation License)

For more information (background, pictures, experiments and references): North Atlantic Right Whale