University of Tübingen Research Points to Human Impact and Climate Change in Woolly Rhinoceros Extinction

An international research team led by Professor Hervé Bocherens from the Senckenberg Centre for Human Evolution and Palaeoenvironment (SHEP) at the University of Tübingen has investigated the causes of the extinction of the woolly rhinoceros after the end of the last ice age 10,000 years ago. In their study, now published in the journal “PNAS” and led by researchers from the universities of Adelaide and Copenhagen, the scientists show that constant hunting by humans, together with temperature changes, permanently weakened the animals’ populations, meaning they could no longer move to more favorable habitats. Their disappearance also highlights the threat to today’s large wild animals, say the researchers.

The woolly rhinoceros ( Coelodonta antiquitatis ) was an iconic member of the steppe fauna of central and northern Eurasia for thousands of years after evolving in the Tibetan Plateau about 2.5 million years ago. With thick skin and long, woolly fur, it was adapted to cold temperatures and was about the size of today’s African white rhinoceros. Woolly rhinos grazed low vegetation in dry, open landscapes and probably used their front horn to expose food under a thin layer of snow. Fossils show that the woolly rhinoceros was widespread throughout northern Eurasia until about 35,000 years ago. Why it became extinct about 10,000 years ago has been controversial in research to date – but human influence has rarely been considered. The newly published study suggests that the animals reached a dead end around 30,000 years ago, when cooler temperatures and low but constant hunting by humans forced the woolly rhinos south. At the end of the last ice age, they were trapped in isolated, suboptimal habitats. The weakened populations were ultimately no longer able to migrate to more favorable habitats.

“We used complex computer models, fossils and fossil DNA to continuously reconstruct the metapopulation dynamics of woolly rhinos over 52,000 years in unprecedented detail,” reports Hervé Bocherens from the Senckenberg Centre for Human Evolution and Palaeoenvironment (SHEP) at the University of Tübingen. He continues: “As temperatures cooled and hunting continued – in some areas of Eurasia, wild animals provided up to 30 percent of the protein intake of humans at the time – the populations and their range shrank. Modern humans, Neanderthals and other hominins lived with the woolly rhinos for tens of thousands of years. On average, they decimated their population by ten percent in each generation. In the end, all that remained were isolated populations that were pushed southwards, weakened and isolated. When temperatures warmed again at the beginning of the Holocene 11,000 years ago, the woolly rhinos were then ‘trapped’ in areas that were climatically suboptimal for them and eventually disappeared completely.”

The researchers also see the results of their study as providing important information for the protection of today’s large wild animals. Due to the serious consequences of land use changes and hunting by humans, most of the remaining species of today’s megafauna only occur in a fraction of their historical range. “While there were 61 large herbivores weighing over 1,000 kilograms in the late Pleistocene, only eight such species remain today. Five of these are rhinos, four of which are endangered and three are even threatened with extinction,” explains Bocherens. The animals live in highly fragmented and rather unfavorable ranges in Africa and Asia. “Due to global warming, their situation will worsen even further in the coming years. We urgently need increased protection measures to prevent today’s rhinos from suffering the same fate as their relatives, the woolly rhinos,” concludes Bocherens.