Blue Whale Study spots males racing in rarely seen courtship ritual off SA coast

Blue Whale Study spots males racing in rarely seen courtship ritual off SA coast
  • PublishedApril 4, 2024

A veteran researcher has spotted a dramatic blue whale courting ritual off Australia’s southern coast for just the second time in his 26 years studying the massive creatures.

Blue Whale Study’s Peter Gill said his team was conducting a survey from an aircraft off the coast of Port Macdonnell in SA’s South East late last month when three whales were seen speeding through the water.

“Typically it’s an adult female in the lead being pursued by two presumably amorous males who are competing with each other very physically to try and displace each other,” he said.

“It’s sort of when the whales are pairing up prior to their migration away from our southern Australian feeding grounds to their breeding grounds, which are up in Indonesian waters.”

It is only the second time Dr Gill has seen the behaviour in the study’s research area, which extends from the Great Australian Bight to the Bass Strait.

“If you were in a small boat and you saw this coming towards you, you’d be well advised to start your motor and get out of the way,” he said.

“These are animals that weigh 120 to 140 tonnes each … [and are] travelling at 15 to 20 knots.

“It’d be like being hit by a B-double truck, only much heavier — or perhaps a train’s a better analogy.”

Three blue whales in the ocean, as seen from above.
The male whales shouldered each other and lashed out with their tails during the chase.(Supplied: Blue Whale Study)

‘Full-on combat’

Dr Gill said the rare sight was “possibly the most spectacular animal behaviour” a person could witness.

“You’ve got three of these massive animals just engaged in this full-on combat between the two chasing males,” he said.

“They’re shouldering each other aside and hitting each other with their tails a bit.

“The female’s just out in front setting the pace … she slows down when she wants to have a rest and the two boys both slow down too and trail behind her, and then she’ll power off again and off they go.

“Presumably she’s going, ‘OK, boys — who’s it going to be?’

“I hesitate to use the words ‘leading them on’, but she’s definitely leading them on physically.”

Dr Gill said researchers observed the behaviour for about 15 minutes before leaving the whales be.

“It has been seen off California and eastern Canada, other places where people study blue whales,” he said.

“It’s a huge expenditure of energy for these animals.”

A whale coming up from the ocean.
The Blue Whale Study covers the Great Australian Bight to Bass Strait.(Supplied: Bob McPherson)

Fewer sightings

The sighting comes amid the Bonney coast upwelling, when cold and nutrient-rich water comes to the surface off SA and western Victoria during summer.

But Dr Gill said a “monster” upwelling had not brought the expected “bonanza of food” for marine animals.

“[The female] did look a bit skinny – her backbone was quite accentuated – but the other two did seem to be in fairly well-fed conditions,” he said.

“But yes, that is something we are concerned about.”

A drone photo of a boat in the water with thousands of silver fish thrashing around it.
The Bonney upwelling caused a salmon feeding frenzy off the coast off Cape Jaffa, SA, last month.(Supplied: Leah Bailey)

Dr Gill said it was “not a good year for life” in the upwelling zone.

“We’re struggling to find blue whales [and] we’re struggling to find krill swarms,” he said.

“I know that the tuna fishermen from Port Lincoln are not finding the fish in their usual places this year.

“The rock lobster fishermen down around Port Mac are reporting not a very good season.

“These upwellings need to settle down and warm up a little bit and let the food supplies develop, but that just doesn’t seem to be happening this year.”


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