Southern right whale: the right stuff

Name: Southern right whale (Eubalaena australis)

Size: Length: up to 18 metres long. Weight: around 80 tonnes.

Diet: Generally copepods, but known to consume krill and plankton.

Habitat/range: Migratory between Antarctic waters and generally the southern Australian coast from Perth, Western Australia to Tasmania and New South Wales.

Conservation status: Endangered

Superpower: Right whale males have the largest testicles of the animal kingdom – around 500kg each (that’s one tonne per male). 

Two southern right whales
Southern right whales, Sydney 2016. Credit: DrVPirottaMQ

With facial features (callosities) comparable to foot bunions, and holding the record for the world’s largest testicles, it’s no surprise that the southern right whale is a leading contender for this year’s Australian mammal of the year. Deep dive with me as we introduce the whale with the right stuff.

To best understand the southern right whale, think big! These whales are massive air-breathing mammals – with hair (yes, whales have hair). Imagine a bus giving birth to a car, and you can grasp the scale of these marvellous creatures’ reproductive feats. In addition to their size, they are super low-lying in the water, with no dorsal fin. This makes them a kind of a stealth whale, which makes it tricky for researchers trying to tag them on a boat. In addition, these animals come equipped with an inbuilt snorkel, aka nose, which is located on the top of their head. Right whales are also famous for producing love heart-shaped plumes when they breathe – how cool is that?


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Each winter, Australia is treated to a blubbery spectacle in key nursey and breeding grounds close to shore, as southern right whales birth their calves and spend time together. Females are pregnant for 11-12 months and give birth to a single calf where they remain for a few months before making the return journey back to Antarctic waters for the summer to feed.

What about the blokes? Well, the male southern right whales don’t miss out on all the fun and are known to hang out with females in groups. Sometimes prior to mating with a female, a male will use his sperm to flush out the sperm of a previous mate in order to ensure his genes are passed on the next offspring.

southern right whale breaching
Southern right whale. Credit: wildestanimal/Getty Images

Originally named the “right whale” due to their high oil and fat content, these whales were nearly hunted to extinction. They remain a threatened species in Australian waters. Fortunately, like all whales in Australian waters, they are now protected – but are still vulnerable to many human-made and natural threats.

Unlike the humpback whale populations in Australian waters, their recovery remains slow. One of the reasons is due to a slower reproductive interval between calves, which is every three to five years. Scientists continue to closely monitor their recovery and have implemented citizen science programs to identify individual whales based on their facial/head callosities arrangements, which are unique to each whale.

The verdict? These giant, blubbery, loveable, bus-sized marine mammal ought to have won you over by now. If the giant testicles haven’t convinced you, then surely the southern right whale is the “right” choice for your vote.

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