In 1893, the World’s Fair was getting under way in Chicago, the world’s first number plates appeared on cars in Paris, and Archduke Franz Ferdinand, whose assassination would later spark the first world war, spent time hunting kangaroos and emus in the NSW town of Narromine.
Also, according to researchers, up to 10% of southern right whales in existence could have still been swimming the ocean today, if not for other factors.
The research, published in Science Advances, found southern rights lived to a median age of 73 years old, with up to 10% surviving past 131 years – as long as they avoided death due to industrial whaling, ship strike or entanglement.
This made them the second-longest lived mammals on Earth, after bowhead whales – another baleen, or filter feeding species – which could live beyond two centuries.
The age of bowheads, based on laboratory techniques, was also supported by archaeological evidence. This included one individual, taken in the modern Indigenous hunt in 2007, which still had an explosive Yankee Whaler harpoon tip, last manufactured in 1885, embedded in its blubber.
Co-author of the research Dr Peter Corkeron, an adjunct senior research fellow at Griffith University, said whales alive today could have been around during Australia’s convict days, if they reached their full lifespan.
They would have endured a bloodbath. “Industrial whaling, which for most species ended only 60 years ago, would have required any individuals now aged over 100 years to have survived at least 40 years of intense whaling,” the paper said. “Any individual over 150 would have had to survive 90 years of the same intense hunt.”
Instead of techniques that analysed the ear plugs or eyes of dead animals, the study estimated the lifespans of southern and North Atlantic right whales by modelling their patterns of their survival, drawing on global and South African databases that tracked re-sightings of individual whales over more than 40 years.
Right whales have unique textured patches called callosities on their noses, or “rostrum”, that meant individuals could be identified in photos decades apart. For example, one North Atlantic right whale that died in the mid-1990s, after being hit by a ship, was traced back to a photograph from the 1930s, Corkeron said.
Geographe Marine Research chair, Dr Capri Jolliffe, a marine mammal scientist who was not involved with the research, said whales had long life histories and long memories.
“Whaling didn’t cease that long ago. There’s whales out there today that were alive during whaling times, so they probably have that memory of being hunted by humans,” she said.
Right whales took their name from being “the right whale to hunt”, Jolliffe said. They were an easy target, being “quite chunky” and spending a lot of time at the surface.
As a result, their populations had been decimated, she said. Three species – North Atlantic, North Pacific and Southern right whales – were endangered globally, and remained at risk from entanglement in fishing nets, ship strike, noise, pollutants and climate change.
“We’re very lucky in Australia,” Jolliffe said. “We have southern right whales that migrate to our coastline every year”.
They foraged in productive Antarctic waters and migrated north to give birth in sheltered, warmer waters along the Australian southern coast, where babies played together while the mums rested, she said.
Commercial whaling ceased in Australia in 1979 and was banned by the International Whaling Commission in the late 1980s. In decades since, some populations of southern right whales have slowly recovered.
The estimated lifespans of North Atlantic right whales revealed a “different, sadder tale”, Corkeron said. Their median lifespan was “about a third of what it should be” at 22 years, he said, and was artificially limited by human causes such as vessel strike and entanglement.
Whale scientist Dr Vanessa Pirotta said whales were long-lived animals “just like us”.
“The good news is that whaling in most areas around the world has stopped,” she said, but some species such as North Atlantic right whales were not recovering, making research into their biology and lifespans “incredibly timely” and critically important to their conservation.
Corkeron said whaling had artificially changed the age structure of right whale populations – by removing larger, older animals – contributing to the “misplaced view” that they only lived to their 70s.
“We were thinking about these whales all wrong,” he said. “It’s impeded our ability to get it right when it comes to doing the science for conservation to stop these whales from going extinct.”
