Unfussy eating 'helped save cougar'
Unfussy eating habits may have helped the North American cougar survive the mass extinction that wiped out most of its big-cat cousins 12,000 years ago, scientists believe.
New research suggests the sabre-toothed cat and American lion were both more picky about their food, turning their noses up at carrion and the less tasty parts of prey.
As a result both perished along with the woolly mammoth and many other large "megafauna" that went extinct at the end of the Pleistocene era.
"Before the Late Pleistocene extinction six species of large cats roamed the plains and forests of North America," said Dr Larisa DeSantis, from Vanderbilt University in Nashville, US. " Only two - the cougar and jaguar - survived.
"The goal of our study was to examine the possibility that dietary factors can explain the cougar's survival."
The meals a large carnivore consumes during the last few weeks of its life leave tell-tale marks on the animal's teeth.
Chomping on red meat, for example, produces small parallel scratches while crunching on bones adds larger, deeper pits.
The scientists compared the teeth of 50 fossil and modern cougars with those of sabre-toothed cats and American lions excavated from a natural tar pit site in Los Angeles.
A comparison was also made with the teeth of modern African carnivores, including cheetahs, lions and hyenas.
Previous research by the same team had shown that the dental wear patterns of extinct American lions closely resemble those of modern cheetahs - extremely finicky eaters that mostly consume tender meat and rarely gnaw on bones.
Sabre-toothed cats were found to be similar to African lions and chewed on both flesh and bone.
Analysis of the ancient cougar teeth revealed that, unlike the other cats, its individual dietary preferences varied greatly.
While some animals appeared to be fussy eaters, others showed tooth wear patterns closer to those of the modern hyena, which consumes every part of its prey, including the bones.
"This suggests that the Pleistocene cougars had a more generalised dietary behaviour ," said Dr DeSantis. "Specifically, they likely killed and often fully consumed their prey, more so than the large cats that went extinct."
Tellingly, modern cougars - descended from ancestors that survived the mass extinction - are opportunistic predators and scavengers which fully consume the carcasses of both small and medium-sized prey, the scientists point out in the journal Biology Letters.
Their forebears' variable dietary behaviour may have been "a key to their survival", they conclude.