Southern Right Whale

The Southern Right Whales are one of the three Right Whale species in the Eubalaena genus. This Baleen Whale species can be easily distinguished by the presence of the callosities on their heads. They are a close relative of the North Pacific Right and the North Atlantic Whales. These whales are mainly found in the Southern Hemisphere.

Scientific Name

The scientific name for this species is Eubalaena australis.

Description

Their appearance is very similar to that of the North Pacific Right Whales and North Atlantic Whales. But there are some differences in the scull structure of these three species. Here is a general description of the whales of this species:

Size: The males can grow between 11 meters to 18 meters while the females grow up to 15 meters in length. Their calves are approximately 5.5 meters long.

Weight: Their weight ranges between 40 tons and 70 tons. The calves weigh around 1.5 tons after they are born.

Color: They are generally dark grey or black in color. Their bellies are sometimes marked with white stripes and patches.

Body: Southern Right Whales have large and stocky bodies with long wide flippers. They do not have any dorsal fins.

Head: Their large heads make up one third of their total body length. The heads are covered with white outgrowths that are known as callosities. Large Cyamid or Whale lice colonies can be found on the callosities. The upper jaws and chins are covered with hairs.

Baleen Plate: Dark baleen plates are attached to their upper jaws. There are approximately 225 plates situated on each side.

Tail: Their tails are generally black in color. The deeply notched tails have smooth trailing edges.

Picture 1 – Southern Right Whale

Distribution

This species is native to the southern regions of the Southern Hemisphere. Their distribution range extends form temperate to polar latitudes. They are found in latitudes between 20 °S and 60 °S. The areas of distribution include Brazil, Falkland Islands, False Banks, South Georgia, Shag Rocks and Antarctic Peninsula. The northern range of their distribution includes the coasts of South Africa, Australia, New Zealand and Argentina.

Migration

These mammals migrate to the northern regions of their distribution range for breeding. Migration takes place in winter and spring. During migration, they are mainly seen in the coastal areas of Australia, New Zealand, Argentina, Chile, Mozambique, Namibia, Brazil, Peru, Madagascar, Uruguay and South Africa.

Habitat

Southern Right Whales inhabit open waters in the southern hemisphere. They tend to stay in habitats with abundant prey populations during the summer months. During winter, they generally live in coastal areas.

Diet

They primarily feed on zooplanktons such as krill and copepods. These baleen feeders hold their mouth open and swim through zooplankton patches. Their baleen plates filter the food from the water.

Picture 2 – Southern Right Whale Image

Behavior

Find about the behavior patterns of this whale species:

They remain active both during day and night.
This species spend almost half of their time feeding.
Like all Baleen Whale species, these whales are seasonal feeders. They mainly eat during summer.
They are known to swim at speed of up to 5 km per hour.
Female Southern Right Whales are generally seen with their calves.
They sometimes swim in groups of up to 20 Whales.
One unique behavior of this species is that they sometimes extend their flukes for catching the wind by assuming a vertical position. This behavior is commonly known as “sailing”.

Predators

Large Sharks and Killer Whales are known to prey on the Southern Right Whales. Kelp Gulls are also known to feed on live Whales of this species. This predatory behavior is mainly seen in various regions of Argentina.

Adaptations

Their adaptive features help them to survive in their natural habitat.

The kidneys of these mammals are not able to process even a small amount of salt water. Due to this reason, their baleen plates filter the salt water to prevent any possibility of swallowing it.
The hairs on their jaws and chins can work as vibrissae and help them to forage under water by detecting the change in prey density.
These whales have developed insulator Integumentary system that has made them bulky and slow moving. It is an adaptive feature that helps them to live in cold waters.

Mating Season

The mating season continues from June to November. The Southern Right Whales are known to reproduce in alternate years.

Reproduction

They become reproductively mature between 6 and 10 years of age. Several males can mate with a single female. The female Southern Right Whales give birth to one calf after a gestation period of a year. The females arrive near the coast lines to give birth to their calves.

Picture 3 – Southern Right Whale Skeleton

Life Cycle

The females feed their calves with milk for approximately 1 year after their birth. Their size and weight increase considerably during this period. The young Southern Right Whales move to the nutrient rich waters of Antarctica once they become old enough. These whales maintain long term mother-calf relations.

Lifespan

Their exact lifespan is unknown in the wild. But they are believed to live above 50 years.

Interesting Facts

Here are some interesting facts about this Whale:

They are known as the Right Whales because whale catchers considered them to be the right kind of Whale to catch due to their large size and slow movement.
The Whales of this species float when dead.
They can swallow 1.5 to 2 tons of zooplankton per day.
One female can mate with up to eight males.
The Southern Right Whales are believed to have the largest testicles among all mammals. Each of their testicles weighs around 500 kg.
Hermanus in South Africa has become one of the world famous Whale watching centers because of this species.

Conservation Status

This species is included in the “Least Concern” Category by the IUCN. Their populations are protected by various laws in many places including Australia, Argentina, Chile, Brazil, South Africa and New Zealand. The main threats to the Southern Right Whales include fishing and coastal developments.