Southern Right Whale – Full Explainer & Fact-sheet
Name & Naming of the Southern Right Whale
1. Why are they called “Southern” right whales?
The adjective “Southern” is purely geographic. The species lives only in the Southern Hemisphere, with a circumpolar distribution between ca. 20° S and 60° S. Its two congeneric cousins, the North Atlantic right whale and the North Pacific right whale, are restricted to the northern hemisphere. Thus “Southern” separates the three right whales by hemisphere and, implicitly, by ocean basin.
“Found only in the southern hemisphere a circumpolar distribution between 30 and 50 degrees south.” (Animal Diversity Web, 2025-09-21)
2. What is the scientific (Latin) name?
The valid, internationally accepted scientific name is Eubalaena australis (Desmoulins, 1822).
- Genus: Eubalaena, meaning “true (eu) whale (balaena)”.
- Species epithet: australis, Latin for “southern”.
“Scientific Name, Eubalaena australis; Author, (Desmoulins, 1822)” (OBIS-SEAMAP taxonomic authority file)
3. How did Southern right whales get their name?
The phrase “right whale” was coined by 17th- and 18th-century whale hunters. These whales were literally the right ones to pursue because a combination of traits made them extraordinarily profitable-and easy-targets: they swim slowly and often within sight of land, they float when dead due to high blubber content, yield enormous quantities of oil and baleen, and are relatively placid and approachable.
“They were named because whalers decided they were the ‘right’ whale to hunt as they moved slowly… and produce a large amount of oil when harvested.” (WWF-Australia, 2023-02-21)
“The Southern Right Whale was called a ‘right whale’ as it was the right whale to catch because of its meat and high oil content.” (The Australian Museum)
Appearance & Biology
1. What do Southern right whales look like?
They are jet-black, rotund whales with an enormous, rounded head (up to one-third of total length), no dorsal fin, long arched mouth-line, and huge square pectoral flippers. The blow is a dramatic, bushy V up to 5 m high. They have raised white “callosities” on the rostrum, chin, lips, and around the blowholes, which give each animal a unique “face.”
“Large, rotund, bulky whales with broad backs… head extremely large, up to a third of body length… no dorsal fin… mouth-line dramatically arched… tail flukes wide with smooth trailing edges.” (Whale & Dolphin Conservation USA)
2. Do Southern right whales have a dorsal fin?
No. They are the only large whale that completely lacks a dorsal fin or even a dorsal ridge.
3. What are callosities on Southern right whales?
Callosities are patches of thickened, keratinised skin, analogous to heavy calluses on human feet. They are present at birth and remain for life. Their position never changes, only their thickness.
4. How are individual Southern right whales identified?
Because each whale’s callosity pattern is unique and permanent, scientists photograph the head from both sides and catalogue the shape and number of callosities. Scars, lip notches, white belly blazes, and tail-fluke nicks provide secondary identification codes.
“The placement and pattern of the callosity is unique to each individual and is how scientists distinguish one right whale from another.” (New England Aquarium)
5. What color are Southern right whales?
They are predominantly jet black. Dark-brown or grey variants occur, and about 3-5% of animals are almost entirely black. Calves are sometimes born silvery-grey but darken within months.
6. Do Southern right whales have white patches?
Roughly one-third of the population shows irregular white areas, usually on the belly or chin. These patches are skin pigmentation and are stable for life, so they are included in photo-ID catalogues.
7. How do callosities help in research?
They are used for mark-recapture studies to determine survival, birth, and migration rates. They also help in abundance estimates, tracking social structure, and assessing health, as sudden loss of callosity height can indicate nutritional stress or disease.
8. How long can Southern right whales grow?
Adult females average 15-17 m, with a verified maximum of 18.5 m. Adult males average 14-16 m, with a maximum of about 17 m. Newborn calves are 4.5-6 m long.
9. What is the average weight?
Females are 60-80 tonnes and males are 50-65 tonnes. Extremely fat pregnant females have weighed 90-100 tonnes.
10. How much do males weigh compared with females?
Females are typically 10-20% heavier and up to 1 m longer than males, a phenomenon called sexual size-dimorphism.
11. Do females grow larger than males?
Yes.
12. What is the maximum length recorded?
18.5 m for a female at a whaling station in Durban, South Africa, in 1912. The longest scientifically measured living animal was 18.3 m off Argentina in 2016.
13. What parasites live on Southern right whales?
They host cyamids (“whale lice”), barnacles, and endoparasites like nematodes. All are commensal or mildly parasitic, and none are known to kill healthy whales.
14. What is the V-shaped blow?
The two blowholes are angled outward. When the whale exhales, the twin columns of warm, moist air converge at the top, forming a heart- or V-shaped plume up to 5 m high. This is visible from several kilometres and is a key field mark.
“A well-partitioned blowhole results in a V-shaped exhaust of condensation and water vapour.” (Animal Diversity Web)
15. Can we see from the outside if it’s a boy or girl?
No. There is no external dimorphism other than average size. Reliable sexing requires genetic biopsy or observing a calf alongside the mother.
16. Can a whale see its “nose”?
Whales have no projecting nose. The blowhole is on top of the head, and the eyes are 2-3 m behind it, so a right whale cannot see its own blowhole.
17. Can it feel with its skin?
Yes. The dermis contains numerous mechanoreceptors and nerve endings. Whales react to touch, indicating pain or pressure perception.
18. How big is the heart?
About 150-180 kg, roughly the size of a small motorbike. Each beat pumps about 60 L of blood.
19. How good is their hearing?
They are low-frequency specialists, ideal for long-range contact in murky coastal waters. There is no evidence of echolocation, and hearing is thought to be bone-conducted through the mandible fat pad.
20. How do Southern right whales compare to North Atlantic right whales?
| Feature | Southern (E. australis) | North Atlantic (E. glacialis) |
|---|---|---|
| Length | 16-18 m | 13-16 m |
| Population trend | Increasing (7% yr⁻¹) | Critically declining |
| Reproduction | 1 calf / 3 yr | 1 calf / 4-6 yr |
| IUCN status | Least Concern | Critically Endangered |
21. Differences from North Pacific right whales (E. japonica)?
- Size: North Pacific slightly larger (females 18 m max).
- Range: Completely separate hemisphere; no range overlap.
- Vocalisations: North Pacific produces very distinct “gunshot” calls not recorded in the Southern species.
- Genetics: Mitochondrial lineages diverged ~3 million years ago.
22. Are Southern right whales larger than humpback whales?
Yes. Humpbacks max out at 15-16 m and 40 t, while a large female Southern right whale is both longer and up to twice the mass.
23. How do they differ from blue whales?
| Feature | Southern right | Blue whale |
|---|---|---|
| Body shape | Stocky, no dorsal fin | Streamlined, small dorsal fin |
| Colour | Black with callosities | Mottled blue-grey |
| Length | ≤ 18.5 m | 25-30 m |
| Weight | ≤ 90 t | ≤ 150 t |
24. Do they have larger testicles than other whales?
Absolutely. Each testis weighs 500-900 kg, together about 2% of body mass, making them the greatest absolute and relative size in the animal kingdom. The record pair from a 16 m male weighed 1.98 t.
“Each testicle can weigh up to 500-900 kg… about as heavy as a newborn grey whale or an adult horse.” (Whale Scientists)
25. What made them easier to hunt?
They are slow swimmers, have a coastal habitat, float when dead due to high blubber content, yield large amounts of oil and baleen, and are non-aggressive.
26. How does the blow compare to other species?
- Right whale: low, wide V, 4-5 m.
- Humpback: tall, columnar, 3 m.
- Blue: tall, slender column, 6-9 m.
- Sperm: angled, forward bushy jet, 5 m.
27. Similarities with bowhead whales?
They both lack a dorsal fin, are skim-feeders on copepods, have a huge, bowed head with callosities, and have similar longevities (≥ 100 yr) and low reproductive rates.
28. Size comparison with other baleen whales (adult females)
| Species | Length | Mass |
|---|---|---|
| Blue | 25-30 m | 120-150 t |
| Fin | 22-24 m | 70-90 t |
| Sei | 17 m | 25 t |
| Bryde’s | 14 m | 20 t |
| Humpback | 15 m | 40 t |
| Southern right | 17 m | 70 t |
| Gray | 14 m | 35 t |
29. How do researchers track them?
- Photo-identification: callosity catalogues (since 1979).
- Satellite telemetry: implant or suction-cup tags give 200-day migrations.
- Genetic biopsy: population structure, paternity, sex.
- Acoustic loggers: detect low-frequency moans on breeding grounds.
- UAV drones: body condition, photogrammetry, calf growth.
30. What role do they play in the ecosystem?
They act as a “whale pump” by feeding in plankton layers and defecating nutrient-rich fecal plumes in coastal breeding bays. They are also a “carbon sink,” as carcasses that sink to the ocean floor sequester carbon for centuries. Additionally, they create unique micro-ecosystems on their bodies and in “whale-fall” communities from their carcasses.
Feeding Ecology of the Southern Right Whale
1. What do Southern right whales eat?
They are almost exclusively zooplanktivores, primarily consuming krill and calanoid copepods, and occasionally larval stages of squat lobsters and fish eggs.
“They feed on small plankton, including pelagic larval crustaceans and copepods… krill and copepods, which are tiny crustaceans found in nutrient-rich waters.”
2. How do Southern right whales feed?
They are continuous ram-filter feeders, using two main tactics: surface skim-feeding, where they travel with their mouth half-open through plankton slicks, and sub-surface feeding, where they roll onto their side to feed near the sea floor.
3. Are Southern right whales filter feeders?
Yes, they are obligate filter-feeders. They take in seawater and expel it laterally through their baleen plates, trapping prey on the inside fringes.
4. What type of plankton do they consume?
They are size-specific zooplanktivores. The fringe spacing of their baleen (~0.25 mm) retains copepods 1-6 mm long and adult krill 10-25 mm, while nanoplankton or phytoplankton slip through.
5. How much food do Southern right whales eat daily?
Energy-balance models estimate they eat 1.5–3 tonnes of wet krill or copepods per day during the 4–5 month Antarctic feeding season.
“In Antarctic waters they consume up to 3 tonnes of krill per day during their feeding season.”
6. Do Southern right whales fast during certain seasons?
Yes, they fast completely from June to November, relying entirely on blubber reserves and losing 20–30% of their body mass.
“While in Australia they fast, surviving off stored blubber and often losing 20-30 % of their body weight.”
7. Where do they primarily feed?
They feed in Sub-Antarctic and Antarctic waters between 40° S and 65° S, including areas south of New Zealand, the Antarctic Polar Frontal Zone, and the Weddell Sea.
“Feeding typically occurs in austral summer and fall in regions located around 40°S and 65°S.”
8. What are baleen plates used for?
They are keratinous sieves that filter water, trapping prey inside. The inner edge carries a mat of fine hairs that act like a living filter. Baleen is homologous to your fingernail and grows continuously.
9. How long are the baleen plates?
The longest plates are 2.2–2.8 m, with a record of 3.0 m. They have 220–270 plates per side.
10. Do Southern right whales skim or gulp feed?
They are strictly skim-feeders and never lunge, accelerate, or expand the throat pouch like rorquals (e.g., humpbacks).
11. Do they like kelp?
They swim through kelp beds but do not ingest kelp, as it has no nutritional value for them.
Reproduction & Family Life of the Southern Right Whale
1. How do Southern right whales reproduce?
They are viviparous placental mammals. Fertilisation is internal, and a single calf is born after a year-long gestation. Females are polygynous, mating with several males in quick succession to allow for sperm competition.
“Courtship and copulation is described as being tender and graceful… there seems to be no animosity between males mating with the same female… intra uterine sperm competition.” (Animal Diversity Web)
2. At what age do females mature?
The mean age for first ovulation is 7–8 years, and first calving is at 8–10 years.
“Average age at sexual or reproductive maturity (female): 10 years… youngest recorded… five for two individuals in South Africa.” (ADW ; Springer chapter)
3. How often do they give birth?
One single calf every 3 years is the long-term average. The sequence is a year of gestation, a year of lactation, and a year of rest to rebuild blubber. Food-poor years can stretch the interval to 4–5 years.
“Females give birth to a single calf every three years… a normal or healthy interval.” (Environment America)
4. Gestation period?
Approximately 12 months (range 11.5–12.5). Conception occurs from June to August, and birth takes place the following winter.
“Gestation period ordinarily lasts for 1 year.” (MarineBio)
5. How do they mate?
Mating occurs in Surface-Active Groups (SAGs) of 2-10 whales. The female often positions herself belly-up to make intromission difficult, and two males can achieve simultaneous intromission.
“It is common for females to position themselves belly-up to avoid mating… two males were observed copulating at the same time with the same female… extended penises of two males entering the genital slit of a female.” (Tito Bottazzi field notes)
6. What are “heat runs”?
A “heat run” is a running, rolling SAG where males follow an oestrous female for hours, frequently changing position. Breaches, flipper-slaps, and bellowing calls advertise stamina.
7. Do multiple males mate with one female?
Yes, guaranteed. Genetic paternity studies of calves showed no fewer than 3 and up to 7 different fathers per calf.
“Southern right whales are polygamous, having up to seven males per one female.” (ADW)
8. What is unique about males’ reproductive organs?
Their testes are the largest of any animal, weighing together up to 998 kg. Their penis is also unusually large, measuring 2.5–3 m long and can be extruded in 15 seconds. They do not have a penis bone (baculum).
“Testicles weighing 998 kg… record for the largest testicles of any animal.” (Whale Scientists)
9. How do mothers care for calves?
Mothers provide nursing with milk that is 53% fat, transport by allowing the calf to swim in their slip-stream to save energy, protection from vessels or killer whales, and teaching of behaviours like breaching and feeding manoeuvres.
10. When is the breeding season?
The austral winter. Courtship and conception peak in July, while birth and lactation peak in August. All activity occurs in 20-30° S coastal bays.
“Mate and calve between 20 and 30° S… during the months of June–November.” (ADW)
11. Size & weight of a newborn calf?
Newborns are 5–6 m long and weigh 1,000–1,500 kg.
“Calves… 5–6 m long… weighing 1 000–1 500 kg.” (MarineBio)
12. Record for largest testicles?
998 kg for the pair (Península Valdés, 1994), which is still the largest ever weighed for any animal.
13. How many babies at a time?
Always one. Twins have never been documented in the wild or in whaling records.
14. Where do they have sex?
Almost exclusively in shallow (<50 m), protected coastal waters used as breeding/calving bays.
15. Do mum & dad stay together and raise the baby?
No, there is no long-term pair bond. After the SAG, males leave and provide zero parental care. The mother alone rears the calf.
16. Where does the dad go?
Males return to feeding grounds or seek other receptive females. They are sighted in the same breeding bays in successive weeks, suggesting a “roaming” strategy to maximise encounters.
17. Do juveniles stay with mum like elephants?
No. Calves separate at 11–12 months (weaning) and seldom travel with the mother afterwards. No multi-year family units exist.
“Calves are usually weaned and independent at the end of their natal year.” (Springer review)
18. How long does the baby stay with the mum?
Approximately one year. Lactation lasts 4-6 months, but calves continue to accompany the female during the northward migration and only become fully independent at 10-12 months.
19. How many babies survive?
First-year survival averages 82–90% in well-studied populations. Major losses are from kelp-gull attacks, killer-whale predation, and ship strike.
20. How much milk do they drink per day?
About 300 L per day at peak lactation (age 2-4 months). A calf can gain 80-100 kg body mass per week.
21. How do they drink?
Underwater, the calf rolls on its side and inserts its tongue into the mammary slit. The mother then ejects milk under pressure, so the calf does not have to suck against water resistance. The process lasts 5–10 seconds and is repeated every 20-30 minutes.
22. Daily growth?
Calves grow at an average rate of 3 cm per day and gain 10-13 kg per day. A six-month calf is already 8-9 m long.
Conservation & Tourism
1. Are Southern right whales endangered?
No. They are classified as Least Concern by the IUCN, although some populations, such as in Western Australia, are still considered Endangered.
2. How many are left?
The global population is estimated at 15,000 animals, with the largest population (~10,000) around Argentina and South Africa.
3. Do they live in family groups?
No, they are solitary or form temporary pairs. They aggregate in breeding bays but do not form permanent family units.
4. How do they communicate?
They use a variety of low-frequency sounds, including moans, trills, and gunshot-like calls.
5. Can you swim with them?
No. It is illegal in all countries to approach, touch, or swim with them without a permit.
6. What are common behaviours?
- Breaching: Launching their body out of the water.
- Spy-hopping: Sticking their head out of the water to look around.
- Tail-lobbing & slapping: Hitting the surface with their tail flukes.
- Sailing: Tail is used as a wind-sail (unique to right whales).
- Nursing: Calf rolls under mum, flippers visible.
- Mating groups: 3-7 males following one female.
7. When do they arrive in Australian waters?
First cows arrive in late May, with the main pulse reaching Victor Harbor and Portland by mid-June. Numbers peak at Head of Bight in July–August.
8. Hermanus season calendar (2025 update)
| Month | What’s happening |
|---|---|
| June | Early arrivals – adults, first mating groups |
| July | Calving starts – cow-calf pairs close in |
| August | Peak density – 60+ whales in Walker Bay daily |
| September | WHALE FESTIVAL (late Sept) – 99% sighting success |
| October | Still busy – calves practise breaching |
| November | Taper off – last moms leave |
| December | Stragglers only |
9. Do they approach boats?
Regularly, especially calves. Operators report “mugging” (whale chooses to stay within 10 m) on 1 in 3 trips in Argentina & South Africa. Mothers tolerate slow drift, and engines are put to neutral until the animal moves off.
10. How to spot them from shore (no boat)?
Scan the horizon for the V-shaped blow (5 m high) or look for a dark, fin-less back rolling slowly.
11. Where are the top three whale-watching spots?
The top spots are in Hermanus, South Africa; Península Valdés, Argentina; and Head of Bight, Australia.
12. Why are these places good for whales?
They offer sheltered, warm, and shallow waters ideal for calves to learn to breathe. Predators are rare, and they are close to deep feeding grounds.
13. Why are these places good for humans too?
They offer cheap and inclusive land-based viewing. They are year-round towns that create jobs for tour guides, marine biologists, and hospitality staff. Speed-limit and no-wake zones create a safer environment, and the locations provide educational value.