In the Bluefish Caves and a mine site in northern Yukon, bones initially believed to be from an ice-age puma or cougar were later identified through DNA analysis from the University of California as actually belonging to cheetahs. Molly Cassatt-Johnstone, a lab technician at the time, conducted the test on the Yukon bones, marking one of her first sample analyses. The surprising revelation led Yukon paleontologist Grant Zazula to realize that the presumed cougars were, in fact, cheetahs.
Decades ago, the concept of examining ancient DNA seemed like science fiction, but now genetic analysis on permafrost-preserved bones has become a routine practice. Cassatt-Johnstone’s discovery of the Yukon Miracinonyx, also known as the extinct American cheetah, led to her becoming the lead author of a research paper in Current Biology, providing fresh insights into the ice-age cat’s diet and habitat range.
Researchers were puzzled by the presence of American cheetahs in the Arctic tundra, as they were traditionally thought to be specialized predators of pronghorn antelope in the lower 48 states, where pronghorns were abundant. Beringia, the land bridge connecting Asia and North America, including parts of Russia, Alaska, and the Yukon, presented a unique environment where the cheetahs thrived. Stable isotope analysis was employed by the study team to investigate the dietary habits of the cheetahs, revealing their exclusive reliance on fish, a behavior uncommon among past and present-day felines.
The study findings indicated that Yukon cheetahs adapted to their environment by capitalizing on the abundant salmon runs, possibly to avoid competition with larger predators like Beringian lions and short-faced bears. Despite genetic similarities to North American pumas, the low genetic diversity of the cheetahs and subsequent lack of adaptive potential might have contributed to their extinction. Zazula suggested renaming this unique northern population from ‘American Cheetah’ to ‘Yukon Cheetah’ to reflect their distinct habitat and behavior. The discovery underscores the ongoing surprises and revelations that paleontologists continue to uncover in the Yukon region.
