Right whales are exceptionally large whales, weighing up to 100 short tons ( 91 t; 89 long tons). The largest right whale recorded weighed a record 13.5 million kg (279,500 lb). Right whales occur off the west coast of Scotland and Ireland. In recent years, a new kind of large whales has become resident there. This is a subspecies, which is genetically distinct.
Right whales are among the most solitary animals in the world. They swim along with hundreds of thousands of other sperm whales. It is believed that they mate during the winter and a single offspring will be born in late spring.
The total number of known right whales is still unknown. Estimate of the current population of whales in the Southern Oceans is about thirty-two, but scientists believe that the true number could be much higher since many whale populations are poorly monitored. The whales travel great distances each season, traveling from the warm coastal areas to the cold ocean currents. During summer, they prefer to stay close to the shore and travel further in the fall. The exact whale population calendar is not known, but estimated population of right whales is about one thousand.
The food habits and lifestyle of these massive whales have remained unchanged for millions of years. For the last three decades, whales have been monitored in the captivity of the New Jersey Shore and the Gulf of Mexico. Over the years, this population has shown an unusual increase in reproductive behavior. During the summer months, the whales spend more time on the sea, feeding in loose pods and traveling longer distances every day.
In southern waters, whales travel further south every summer. There, a new pod is formed near the Barrier Island coastline, with each pod containing about twenty-five pods. The breeding season in southern New Jersey and the Gulf of Mexico runs from late July to early August. After the birth, the mother returns to the maternity pool to nurse her babies. The younger calves swim with the mothers until they are weaned by about twelve weeks old. When they reach the age of one, they return to the open sea.
Southern right whales spend most of their time off the coast of Brazil and Argentina. They feed during the day on debris such as nuts and berries floating in the water or on beaches, and at night they hunt for krill and squids using sonar. They breed at the months of June and July and are joined by a second pod, called a calf, that comes from the North Pacific. The whales make their way back to the Southern Ocean in October, following their winter home in the North Pacific. When they return, they prepare to give birth again. Each pregnancy lasts about ten months and end with a birth in February or March.