Get to know Southern Right Whales
The southern right whale is one of the largest species of whale. Females are between 14 and 16 meters long and males are normally 13 to 15 meters. Depending on their size, they can weigh anything from 40 to 50 tons. Southern rights are found only in the southern hemisphere.
Southern right whales are characterised by a broad back with no dorsal fin, a long arching mouth that begins above the eye and distinctive white markings on their heads. These markings are called callosities and are unique to each whale – similar to fingerprints in humans. Callosities are home to tiny crustaceans called cyamids or whale lice, which gives the callosity a whitish colour. The unique pattern of the callosities enables researchers to identify each whale individually which is key in monitoring their movements and progress.
Despite their significant size, these majestic creatures feed off some of the smallest animals on earth – microscopic zooplankton, krill and small fish. As a member of the baleen group of whales, they don’t have teeth. Instead, they have over 200 tightly packed baleen plates hanging down on either side of their upper jaw. These are made out of keratin like our hair and nails, and are used to filter food out of the water.
Although huge, these gentle giants are surprisingly acrobatic. They can ‘head-stand’ by tipping themselves upside-down vertically and waving their flukes in the air. They can also breach, wave their flippers and slap them on the surface of the water up to ten times in a row.
As with most baleen whales, southern rights migrate from their feeding grounds in the icy waters of the Antarctic to their mating and calving grounds in the warm coastal waters of South Africa, South America and Australia. After giving birth to their calves between June and September, they begin the journey back to the Antarctic in late November. This monumental journey is roughly 5,000 km and can take up to two months to complete. Females return to the same bays to mate and calve every year.
Males do not fight each other to gain mating rights to a female. Instead, the male with the largest testes, and thus the greatest volume of sperm, has the best chance to father the offspring. Consequently, male southern rights have evolved to have the largest testes in the animal kingdom, weighing up to 500 kg each, with a long prehensile penis (up to 3 meters long). To ensure healthy competition and the best chance of falling pregnant, a female will mate with many males during mating season.
Females tend to give birth every three years. After a pregnancy of about 12 months, a single calf is born. New mothers come quite close to shore as they need to get the calf to the surface of the water for its first breath after it is born. Weighing in at over 900 kg at birth, these youngsters can already swim on their own 30 minutes after they’re born.
Southern right whale mothers invest high amounts of energy in their calves, losing up to 25% of their body volume over a few months of lactation, helping them to grow quickly in preparation for the long journey back to the feeding grounds.
10 key facts about the Southern Right whale and why it’s important to protect their habitat
The Southern Right whale (Eubalaena australis) can be found in subtropical and waters of the southern hemisphere. They are quite curious and playful when they are close to humans.
It is one of the largest species of whale: the average male is 13 to 15 meters long and the average female is about 16 meters. They weigh around 40 tons.
The characteristic calluses on the southern right whales’ skin function like fingerprints, and identify each whale throughout its life. Calluses are elevated areas of skin (more than 5cm thick) on different parts of their heads.
They are calm, curious and quite slow to swim (reaching maximum speeds of 9 to 11 km / h). To communicate they jump and splash their fins in the water.
They can live to be 100 years old!
Instead of teeth these whales use baleen plates to catch their food. Baleen are long sheets of keratin (the same as hair and fingernails) that hang from the top of the mouth. These baleen allow them to feed “by filter”: they open and close their jaws as they swim, using their throat and tongue to push the water back out of their mouths through the beards. This allows the water to flow out while catching the prey.
This species of whale feeds mainly on krill and small fish.
A third of all southern right whales in the world use the protected bays of the Valdés Peninsula in Argentina to mate and give birth between the months of May and December.
These whales can be seen in Argentina (Valdés Peninsula), Australia, South Africa, Chile, Uruguay, Tristán de Acuña (British overseas dependence) and New Zealand.
Unlike the North Atlantic and North Pacific whales, the Southern Right whale has started to recover from centuries of commercial hunting.
Identifying a Southern Right whale
Southern right whales have unique callosity patterns on their heads – similar to finger prints in humans. These patterns – which are stable for life – make it possible to identify them individually. Additionally, distinct dorsal colouration patterns can aid in their identification.
Using an identification software, the callosity pattern of individual whales is extracted from the aerial photographs taken during annual surveys and automatically matched against previously identified southern right whales in the national South African catalogue.
As the callosity pattern of calves are not fully formed, calves can only be identified from birth if they have a distinct dorsal colouration pattern.