Can Snow Leopards Roar? Which Big Cats Roar or Purr

The big cat that does not roar

The genus Panthera has five living species: the lion, tiger, leopard, jaguar and snow leopard. Four of them can roar. The snow leopard is the exception, even though DNA studies show that its closest relative is the tiger, one of the loudest roarers of all.

This makes the snow leopard a useful test case for scientists. Whatever lets lions and tigers roar must be something the snow leopard lacks, and that has helped to overturn an old explanation of how roaring works.

How do big cats roar?

A roar is produced in the larynx, or voice box. In roaring cats, the vocal folds (often called vocal cords) are large and have a flat, square-shaped edge with a thick pad of fat and connective tissue inside. Laboratory studies of lion and tiger larynxes showed that these heavy folds can vibrate at very low frequencies with relatively little air pressure from the lungs, producing a deep, powerful sound.

Roaring cats also have a long, stretchy ligament in the chain of small bones and ligaments that supports the larynx, called the hyoid apparatus. This lets the larynx sit low in the throat, lengthening the vocal tract and making the call deeper and more resonant, rather like a longer organ pipe.

The snow leopard does not have these specialized vocal folds. Its vocal folds are only about 9 mm (0.35 in) long and offer little resistance to the air flowing past, so the cat simply cannot produce the low-pitched roar of its relatives.

The hyoid bone myth

For much of the 20th century, textbooks explained roaring by the hyoid bone. Small cats have a fully bony hyoid apparatus, while big cats have one link that stays partly flexible, and this was thought to be what allowed big cats to roar but stopped them from purring.

The snow leopard does not fit that rule. It has the same partly flexible hyoid as the roaring cats, yet it cannot roar. Anatomical work published in 2002 concluded that roaring depends mainly on the shape of the vocal folds and the long, elastic ligament supporting the larynx, not on whether the hyoid is bony. The old rule is still repeated online, but researchers no longer accept it as the full explanation.

Which cats roar, purr or chuff?

A lion’s roar can be heard up to about 8 km (5 mi) away on a still night; our article Why do lions roar? explains what the call means.

Which cats purr?

True purring is a steady, rumbling sound made both while breathing in and while breathing out, so it can go on without a break. It is typical of the small and medium-sized cats, from house cats and lynxes to ocelots, cougars and the cheetah.

The roaring big cats are generally not thought to purr in this continuous way. Lions, tigers and leopards make soft, purr-like rumbles when relaxed, but these sounds usually happen only on the out-breath. The snow leopard sits in between: it makes purr-like sounds and is reported to purr while exhaling, but researchers disagree on whether this counts as true purring.

The old idea that a cat can either roar or purr, but never both, is a useful rule of thumb rather than a strict law. The exact anatomy of purring is still being studied.

What sounds do snow leopards make?

Snow leopards are fairly quiet animals, but they have a varied repertoire:

• Chuffing (prusten): a soft, puffing snort through the nose, used as a friendly greeting between mates or between a mother and her cubs.
• Mews: short, cat-like calls, often used by cubs and by mothers calling them.
• Yowls and moans: long, wailing calls made mainly in late winter during the breeding season, when females and males search for each other across the mountains.
• Growls, hisses and snarls: warning sounds when a snow leopard feels threatened.

Snow leopards also communicate silently. They spray urine on rocks, scrape the ground and rub their cheeks on boulders, leaving scent messages for other cats along ridgelines and trails.

Why do snow leopards not need a roar?

Lions live in prides and roar to defend shared territory and keep in touch over long distances on open savanna. A snow leopard lives alone at very low density on steep mountainsides, where echoes and wind would distort a roar. Scent marks left along ridges let neighbors know who is about without meeting face to face, and the loud breeding-season yowls carry far enough to bring mates together.