Evrim Yazgin
Cosmos science journalist
Debate has raged among palaeontologists for decades as to whether the now extinct Ice Age megafauna of the late Pleistocene (2.6 million to 11,700 years ago) disappeared because of humans activities.
For one big Ice Age beast – the woolly rhinoceros – it appears that humans did play a role in its downfall, according to new research.
Woolly rhinos (Coelodonta antiquitatis) once thrived in northern Europe, Africa and Asia.
The species could grow to about 3.5m long, 1.5m tall at the shoulder and up to 2 tonnes – roughly the size of the modern white rhinoceros. Both males and females’ snouts were adorned with massive horns which could be more than a metre in length.
Fossils of woolly rhinos appear from about 5.3 million years ago. They appear in ancient human cave paintings more than 30,000 years ago. Their range contracted before the massive creatures disappear from the fossil record about 14,000 years ago.
Woolly rhinos were perfectly suited to the colder climes of the last Ice Age. Their smaller ears reduced heat loss and they were covered in a shaggy coat.
But research published in the journal PNAS shows that sustained hunting by humans played a role in woolly rhinos from accessing favourable habitats as the Earth warmed.
“Using computer models, fossils and ancient DNA, we traced 52,000 years of population history of the Woolly rhinoceros across Eurasia at a resolution not previously considered possible,” explains lead author Damien Fordham, from the University of Adelaide in South Australia.
“This showed that from 30,000 years ago, a combination of cooling temperatures and low but sustained hunting by humans caused the woolly rhinoceros to contract its distribution southward, trapping it in a scattering of isolated and rapidly deteriorating habitats at the end of the last Ice Age,” Fordham says.
“As Earth thawed and temperatures rose, populations of woolly rhinoceros were unable to colonise important new habitats opening up in the north of Eurasia, causing them to destabilise and crash, bringing about their extinction.”
The new research contradicts earlier studies which suggested humans had no role in the demise of the woolly rhinos.
“The demographic responses revealed by our analysis were at a much higher resolution to those captured in previous genetic studies,” says senior author Eline Lorenzen, from the University of Copenhagen in Denmark. “This allowed us to pinpoint important interactions that woolly rhinoceroses had with humans and document how these changed through space and time. One of these largely overlooked interactions was persistent low levels of hunting by humans, probably for food.”
There were 61 species of large herbivore weighing more than a tonne in the late Pleistocene. Today, there are only 8 and 5 of them are rhinos.
“Our findings reveal how climate change and human activities can lead to megafauna extinctions,” says co-author David Nogues-Bravo, also from the University of Copenhagen. “This understanding is crucial for developing conservation strategies to protect currently threatened species, like vulnerable rhinos in Africa and Asia. By studying past extinctions, we can provide valuable lessons for safeguarding Earth’s remaining large animals.”
