Coyotes today are pint-sized compared to their Ice Age counterparts, finds a new fossil study.
Between 11,500 and 10,000 years ago — a mere blink of an eye in geologic terms — coyotes shrunk to their present size. The sudden shrinkage was most likely a response to dwindling food supply and changing interactions with competitors, rather than warming climate, researchers said.
In a paper appearing this week in Proceedings of the National Academy of Sciences, researchers studied museum collections of coyote skeletons dating from 38,000 years ago to the present day. It turns out that between 11,500 and 10,000 years ago, at the end of a period called the Pleistocene, coyotes in North America suddenly got smaller.
“Pleistocene coyotes probably weighed between 15-25 kilograms (33-55 pounds), overlapped in size with wolves. But today the upper limit of a coyote is only around 10-18 kilograms (22-39 pounds),” said co-author Julie Meachen of the National Evolutionary Synthesis Center in Durham, North Carolina.
“Within just over a thousand years, they evolved into the smaller coyotes that we have today.”