No, mountain lions are not lions. Mountain lions are pumas, if you want to use the proper name. The scientific name is Puma concolor. In North America the name “puma” is commonly used among the scientific community but cougar and mountain now appear to be more common with the general public. However, the mountain lion is an entirely different species of cat to the African or Asiatic lion. Although, that said, we know that cats within the family of cats are very similar despite their substantial size difference.
It is believed that Columbus was the first person to call this cat a “lion”. This is because of its tawny coat which resembles that of the African lion. And as the puma lives in the high mountains as well as a wide range of habitats including tropical rainforests, seasonally flooded savannas and semi-arid scrub, the word “mountain” was added to the word “lion”. And that is about it on this topic except to say that the puma is famous for having more names than any other mammal in the United States. It can be a bit confusing.
You may remember that Theodore Roosevelt remarked on this and summed up the situation well in 1901 when he wrote:
“No American beast has been the subject of so much loose writing or of such wild fables as the cougar. Even its name is unsettled. In the Eastern States it is called panther or painter; in the Western States, mountain lion, or towards the south, Mexican lion. The Spanish-speaking people call it simply lion. It is, however, sometimes called cougar in the West and Southwest of the United States and in South America, puma.”
I have a page on the names given to the puma which expands on what I’ve stated above – click here to read it. Interestingly, the puma has a large body the size of a big cat but the “cranial proportions of small cats”. Pumas do not roar like lions and leopards but they purr like your cat companion sitting on your lap. Behaviorally, they are a sort of hybrid between the domestic cat and the big cats and can be quite shy. They are not classified within that big cat category because only the big cats roar although there is some discussion about that as well.
One last point: the French naturalist Georges Buffon was the man who coined the name “cougar” which is a contraction of the word “cuguacuarana” which may be an error as it may have been incorrectly transcribed from a Tupi Indian word for false deer, “sassúarána”. The word “cougar” has been adopted to mean a predatory middle-aged female to confuse matters even more.