Domesticated housecats share an amazing amount of DNA with tigers – 95.6% actually. In evolutionary history, our furry feline pets became domesticated not that long ago, around 5,000 to 12,000 years. There are many similarities between domesticated cats and wild cats, but why can big cats roar and domesticated cats can’t? It all comes down to a small bone. Cats that roar can’t purr, and cats that purr can never roar.
The cat family (Felidae) is split with the big four cats who roar – lions, tigers, jaguars and leopards – in the sub-family Panthera, and cats who can only purr in the sub-family Felinae, which includes the domesticated cat as well as the bobcat, cheetah, mountain lion and other small wild cats. The mountain lion is the largest of the small cat species, and the tiger is the largest of the big four cats that roar.
What’s interesting about the cat family is their shared instinctive behavior. A head-butt is an appropriate greeting; a wiggle of their behind signals a readiness to pounce; they knead, paw at their food and have an exceptional sense of smell. Around half of all domesticated cats love catnip, which is the same in big cats. All cats, regardless of size, hiss, yowl, snarl, spit and growl. They all love to play, and even wild cats are obsessed with boxes. But when it comes to the ability to roar, not all cats can because of a small bone called the hyoid, which is a U-shaped bone in the throat that sits above the larynx.
The hyoid bone in the roaring cats is flexible and, along with a specialized ligament that stretches, allows these cats to produce a wider range of pitch. As air passes across the vocal cords the ligament is stretched, and the more it’s stretched a deeper and more intimidating pitch is produced.
The shape of the vocal cords also matters. The vocal cords of most animals are in the shape of a triangle. Cats that roar have square vocal cords that are fleshy, unbroken and large. The square shape helps tissue around the cords withstand stretching. This gives roaring cats a much deeper sound while using less lung pressure to produce the sound, which can be as loud as 114 decibels. That’s the same level of sound a jet airplane makes during takeoff, which would be in the painful range for us if standing close by. An adult lion’s roar can be heard five miles away.
In domesticated cats and other wild cats that can’t roar, the hyoid bone is completely ossified. Because it’s non-flexible and hardened, these cats produce a less intimidating and comforting purr. Their vocal cords have specialized folds that are divided and vibrate during inhaling and exhaling. But it limits their range of pitch and prevents the ability to roar.
Our domesticated felines purr at around 25 decibels. Scientists believe one reason cats purr is a sort of self-healing mechanism. A purr can help promote tissue regeneration and aid in bone healing, and your cat’s purrs can also do the same for you. Large cats like bobcats, mountain lions and cheetahs have much larger voice boxes than domesticated cats, but their anatomy is the same as your friendly fluffy kitty and that’s why they can’t roar.
There is one big cat, however, that is an exception to the rule. The snow leopard is a member of the same sub-family as the big four roaring cats and has a flexible hyoid bone, but this cat can’t really roar or purr. The sound a snow leopard makes is called chuffing – a sound that is described as a cross between a meow and a roar. Because of this, many biologists think the snow leopard should be in their own separate sub-family called Uncia.
All cats are obligate carnivores, and they must eat a high protein diet to stay healthy. That’s one good reason to provide your kitty with a premium quality cat food like CANIDAE. Big cats are apex predators and play an important role in maintaining a healthy ecosystem. Without them, farmers sharing land with these predators would find their crops overrun with plant eating animals. Domesticated cats are efficient hunters in their own right and are considered to be semi-domesticated. It’s probably a good thing your kitty can’t roar, though. Being awakened by a roaring hungry cat sitting on your chest at sunrise wouldn’t be a good start to your morning.
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