As it turns out, cats and dogs fighting like, well, cats and dogs was once of evolutionary importance.
By studying more than 2,000 fossils, scientists learned felids that traveled from Asia to North America outhunted the dog family population of wolves, foxes, and other animals, leading to the extinction of about 40 species of canids.
With the big cats getting first dibs on all the prey, the canid population started decreasing substantially—at a rate usually associated with climate change. “We usually expect climate changes to play an overwhelming role in the evolution of biodiversity. Instead, competition among different carnivore species proved to be even more important for canids," explained lead author Daniele Silvestro.
Scientists believe that the cats were simply better hunters than the canids. “The cats have retractable claws which they only pull out when they catch their prey. This means they don’t wear them out and they can keep them sharp. But the dogs can’t do this, so they are at a disadvantage to the cats in an ambush situation,” Silvestro says.
Around 22 million years ago there were more than 30 species of wild canids in North America; today, there are only nine.
The scientists’ findings were published in Proceedings of the National Academy of Science USA.