Southern Right Whale
(Eubalaena australis)

Photo: Mariano Sironi – ICB

Species distribution

Southern Hemisphere between the latitudes 20°S and 64°S.


Adult females can reach 17 meters maximum length and are larger than adult males, which can reach a length of 15 meters. Adults weigh about 40 tons.


These are mysticeti cetaceans, whales which filter their food with hundreds of baleen (keratin plates) up to 2.5 meters in length which are suspended from their upper jaw. They feed on small crustaceans, mainly krill and copepods, and can ingest up to two tons of these small animals per day in summer.

Photo: Nicolás Lewin - ICB
Photo: Paula Faiferman - ICB


Females are 9 years old when they have their first calf. They have a calf every three years. Normally they gestate for one year, then nurse their calf for one year, and finally recuperate for one year before they mate again and have another calf.
Gestation: 12 months.
Calf size: at birth the calf is 4 meters long and weighs one ton; at 3 months of age the calf reaches a length of 8 meters and weighs between 7 and 8 tons.
Maternal lactation: approximately one year. During its first weeks of life a calf can gain up to 150 kilograms per day.


These whales migrate thousands of kilometers annually. In summer and fall they feed in the Argentine ocean’s cold plankton rich waters on the continental shelf and in the vicinity of the Subantarctic Islands. Later in the year they migrate to the temperate waters of the northern patagonian gulfs, the northern sections of the Argentine ocean, to Uruguay and to the southern sector of Brazil where they reproduce in winter and spring.

“La diva de las mares” infographic was published in Clarin newspaper’s / Viva magazine on November 9, 2008.
Source: Instituto de Conservación de Ballenas.

Whales in Patagonia

Each year the gulfs around the Valdés Peninsula (Golfo Nuevo, Golfo San José and Golfo San Matías) receive between 1000 and 2000 southern right whales, out of a total estimated population of 5000 to 6000 individuals. Who arrives?

  • Male and female adults of reproductive age.
  • Juveniles not yet of reproductive age, but who “socialize” with other whales in the area.
  • Gestating females bred a year earlier, ready to give birth to their calves.
  • Adult females with their year old calves which will be weaned during their stay in the gulf.

Annual cycle infographic: Victoria & Eugenia Zavattieri