The question of whether a mountain lion is a “big cat” highlights a common confusion between popular terminology and scientific classification. While the term “big cat” is often used informally to describe any large member of the cat family, Felidae, the strict biological definition is far more restrictive. The mountain lion, known scientifically as Puma concolor, is a large feline native to the Americas. Its official place in the animal kingdom is determined by specific anatomical and genetic markers, not just size.
The Defining Feature of True Big Cats
The scientific classification of a “big cat” is primarily reserved for members of the genus Panthera, which includes the lion, tiger, leopard, jaguar, and snow leopard. This grouping is not based on physical size alone, but on a unique biological mechanism related to vocalization. The ability to produce a true, deep roar is the traditional defining feature of this genus.
Roaring centers on the hyoid bone apparatus in the throat. In Panthera species, the hyoid is only partially ossified, connected by a flexible, elastic ligament. This structure allows the larynx to be depressed, permitting the vocal cords to stretch and vibrate intensely, which produces the deep, resonating sound we recognize as a roar.
This specialized hyoid structure restricts the cats’ ability to purr continuously. The taxonomic distinction of the Panthera genus is rooted in this physical characteristic, uniting these five species under the scientific definition of “big cat.” This classification places the emphasis on anatomical lineage.
The Mountain Lion’s Place in the Felidae Family
Despite its impressive size, the mountain lion, also referred to as a cougar, puma, or panther, belongs to the genus Puma. This genus is part of the subfamily Felinae, which is the same scientific grouping as smaller species like the domestic cat. The mountain lion’s classification in the Felinae subfamily places it outside the Panthera lineage, which defines the true “big cats.”
The mountain lion is the fourth-largest cat species in the world, yet taxonomically, it is classified among the “small cats.” This is because the scientific system prioritizes evolutionary lineage over simple body size. Its closest relatives are actually the cheetah and the jaguarundi, reflecting a distinct evolutionary path from the roaring cats. These regional variations in common names are a result of the animal having the largest distribution of any wild terrestrial mammal in the Western Hemisphere, spanning from Canada to the southern Andes.
Comparing Size, Structure, and Sound
The difference in vocal anatomy provides the most distinct evidence supporting the mountain lion’s classification outside the true big cat group. Unlike the roaring cats, the mountain lion possesses a fully ossified, or bony, hyoid apparatus. This rigid structure prevents the laryngeal descent necessary for roaring, but it enables the cat to purr continuously, both when inhaling and exhaling.
Vocalizations of the mountain lion include purrs, chirps, whistles, and a distinct scream or caterwaul. This wide range of sounds, excluding a true roar, is a direct result of its fully ossified hyoid bone.
While the mountain lion is large, its average size is generally smaller than most Panthera members. Male mountain lions in North America typically average around 136 pounds, though some large individuals can exceed 200 pounds. In contrast, male lions and tigers frequently exceed 400 pounds. The mountain lion also has a distinctive uniform, tawny coloration, which is different from the patterned coats of leopards and jaguars.