In northern Yukon, bones initially believed to be from an ice-age puma or cougar were recently reevaluated through DNA analysis conducted by Molly Cassatt-Johnstone, a former lab technician at the University of California. Surprisingly, the bones turned out to be from cheetahs rather than cougars. This discovery marked the identification of the extinct American cheetah, known as Yukon Miracinonyx.
Paleontologist Grant Zazula shared his initial disbelief upon receiving the news that the supposed cougars were actually cheetahs. The advancement in genetic analysis now allows researchers to routinely conduct such studies on permafrost-preserved bones, a process once considered akin to science fiction.
The revelation of Yukon cheetahs residing in Arctic tundra challenged previous assumptions about their habitat preferences. Contrary to expectations of hunting pronghorns in grassy plains, these cheetahs were found in a region devoid of such prey. To understand their survival, researchers turned to stable isotope analysis, a method that provides insights into ancient diets and environments.
The study indicated that Yukon cheetahs predominantly fed on fish, a behavior uncommon among past and present feline species. This unique dietary preference was likely influenced by the availability of abundant Yukon salmon runs. Additionally, genetic analysis revealed that Miracinonyx was more closely related to North American pumas than African cheetahs, with a limited gene pool suggesting low population numbers and potential extinction risks.
Paleontologist Julie Meachen highlighted the distinct behavior of Yukon cheetahs compared to their counterparts in midcontinental North America, emphasizing their adaptation to a region where they coexisted with formidable predators like Beringian lions and giant bears. The study’s findings suggest that the abundance of fish in the Yukon ecosystem may have contributed to the survival of these cheetahs.
Zazula proposed renaming this unique northern population from ‘American Cheetah’ to ‘Yukon Cheetah’ in recognition of their specialized adaptation to the region. The discovery underscores the ongoing potential for new insights from even the smallest bone findings in paleontological research.