How Big Do Mountain Lions Get? Cougar Size and Weight

Mountain lion size at a glance

The cougar is the fourth-heaviest cat species in the world, after the tiger, lion and jaguar, and the largest cat in North America north of Mexico. It is long and slim rather than heavy, with powerful hind legs and a long, rope-like tail.

On average, North American males weigh about 62 kg (137 lb) and females about 42 kg (93 lb). Males are typically 40–50 percent heavier than females and have broader heads and thicker necks.

Why males and females differ

Male cougars keep growing for longer than females and need to be big to defend large territories against other males. Fights between males can be fatal, so size and strength matter. Females, by contrast, spend much of their adult lives pregnant or raising kittens and stay lighter.

The difference often shows in the tracks as well. Large males leave noticeably wider paw prints, which trackers use as a clue, although young males and big females can overlap.

Size changes with latitude

Cougars show a clear pattern: they get bigger the farther they live from the equator. This trend, known as Bergmann’s rule, is common in warm-blooded animals, because a larger body loses heat more slowly in cold climates.

• Canada and the northern Rockies: the largest cougars. Several males in British Columbia have weighed 86–95 kg (190–211 lb).
• Florida: Florida panthers are medium-sized. Males weigh about 45–75 kg (100–165 lb) and females 29–45 kg (64–100 lb).
• Central America and the northern tropics: the smallest cougars, with many adults weighing well under 50 kg (110 lb).
• Patagonia: cougars in the far south of South America are again large, matching their northern relatives.

Prey also matters. Where cougars hunt large deer and elk, they tend to be bigger than where they feed mainly on smaller animals.

The largest mountain lions on record

The heaviest reliably recorded cougar, shot in 1901, weighed about 105 kg (232 lb). Heavier figures of 118 kg (260 lb) and 125 kg (276 lb) have been reported, but they were probably exaggerated or weighed with the stomach full of food.

Such giants are exceptional. A male of 70 kg (155 lb) is already a large cougar, and many wildlife officers handle adults well under that weight. Reports of 135 kg (300 lb) “monster” cougars in news stories or online usually come from estimates made by eye, which tend to exaggerate size.

How a mountain lion compares to other cats

A large male mountain lion can be more than ten times as heavy as a house cat and four to six times as heavy as a bobcat, which is only about twice the size of a house cat; see how big is a bobcat? for more detail.

Compared with the jaguar, the cougar is slimmer, longer-tailed and longer-legged. In northern Mexico, jaguars and cougars can be similar in weight, but in South America, especially in the Pantanal, jaguars are much heavier and more powerfully built. For a ranking of all the largest species, see biggest wild cats.

Small cat, big prey

For its size, the cougar tackles remarkably large animals. Its usual prey, mule deer and white-tailed deer, often weigh about as much as the cat or more, and cougars in the Rockies regularly kill elk that can weigh three to five times as much as they do.

They manage this with strength rather than bulk. Long, muscular hind legs, heavy forequarters, large front paws with sharp retractable claws and a short, powerful jaw let a cougar leap onto the back of its prey and hold on. Its slim build also makes it agile enough to climb trees and leap about 5.5 m (18 ft) straight up.

How fast do mountain lion kittens grow?

Kittens are born weighing only about 400–500 g (around 1 lb). They are born blind, open their eyes within about the first two weeks and start eating meat at around two months. By about six months they are beginning to catch small prey on their own.

Young cougars leave their mothers at 12–24 months, when they are close to adult size but still lighter and less muscular than mature adults. Males keep filling out for another year or more after independence.