Although this species has been protected under various laws for 60 years, the population seems to have remained fairly constant during this time. Right whales reside in shallow waters that border islands and coastlines. Pregnant cows migrate each year from feeding grounds in the north to the calving grounds located in the southern portion of their range. It is unknown where the rest of the population over winters, although up to 20 percent may remain in the coastal waters off Massachusetts. Cows give birth every three to five years.
Right whales eat small invertebrates called krill and copepods, which live in fairly shallow water.
To catch these tiny animals, the whales swim open-mouthed to allow the water to pass over their baleen plates, which hang down from the upper jaw and are effective strainers. Commercial harvest of the right whale for its oil and baleen was a profitable industry for over 800 years. The oil was used in lamps, and more recently, in cosmetics. Baleen was once processed into corset and umbrella ribs, fans, clock springs, hairbrushes, and riding crops. Clearly the largest threat to the right whale until recently has been human predation.