In the Bluefish Caves and at a mine site in northern Yukon, bones initially believed to be from an ice-age puma or cougar were reevaluated through DNA analysis from the University of California. The examination, conducted by Molly Cassatt-Johnstone, a recent graduate working as a lab technician at the time, revealed unexpected results. The bones, among the first samples she had analyzed, did not match pumas as anticipated, leading to the discovery that they were actually cheetahs.
Grant Zazula, a Yukon paleontologist, vividly recalls the surprising message he received that the “cougars” were, in fact, cheetahs. The identification of a Yukon Miracinonyx, or the extinct American cheetah, marked a significant milestone for Cassatt-Johnstone, who is now the lead author of a research paper published in Current Biology. This paper explores new insights into the ice-age cat’s dietary habits and habitat range.
The American cheetah, characterized by its long limbs and slender physique akin to present-day cheetahs, was traditionally thought to have evolved to pursue pronghorns across grassy plains. However, the discovery of these creatures in the Arctic tundra puzzled paleontologists, given the absence of pronghorns in the Beringia region, connecting Asia and North America.
To unravel this mystery, researchers, in collaboration with Canadian and U.S. partners, conducted stable isotope analysis on bone fragments from the cheetah’s limbs. This technique, also utilized in forensics, provides insights into ancient diets, climates, and potential travel patterns. Surprisingly, the study revealed that Yukon cheetahs primarily subsisted on fish, a unique behavior among past and present felines.
The revelation that Yukon cheetahs favored salmon was a breakthrough for paleontologists like Julie Meachen, who specializes in Late Pleistocene mammalian carnivores. In a region teeming with formidable predators like Beringian lions and giant bears, the abundance of fish in Yukon rivers likely offered an advantageous food source for the smaller cheetahs.
The genetic analysis further unveiled that Miracinonyx was genetically closer to North American pumas than African cheetahs. Additionally, the study indicated low genetic diversity and population numbers, potentially contributing to their extinction. Grant Zazula proposes renaming this distinctive northern population from ‘American Cheetah’ to ‘Yukon Cheetah,’ emphasizing the ongoing discoveries and revelations in Yukon paleontology.