Claws Out: Things You Didn’t Know About Claws
There are plenty of good reasons to avoid Africa’s best-known predators, many of them sticking out of the ends of their paws. Claws are like nature’s Swiss army knife; from climbing, to gripping, to digging, to slicing, these adaptable appendages help animals survive in the wild, whether they’re playing defense, offense, or just playing around!
Fact: Claws are different than nails
Though they’re made of the same substance, keratin, biologists distinguish between claws and nails. Both grow from the ends of digits (fingers and toes), but claws are curved and pointed, where nails are flat and dull.
Fact: Hundreds of mammal species have claws
Many of us associate the idea of claws with big cats (or, for those of us who’ve seen Jurassic Park, velociraptors), but species ranging from bears to dogs to weasels are equipped with these useful tools. They often appear in unexpected places; in fact, the largest clawed carnivore isn’t a big cat, or even a land mammal: it’s a species of elephant seal!
They may not look as scary as a lion, tiger, or bear, but elephant seals have claws, too!
“Mike” Michael L. Baird [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons
Fact: All cats have retractable claws
Big or small, terrifying or just cuddly, all cats’ claws have a special feature: they’re retractable. Cats only have their claws out when they mean to, for hunting, gaining traction against the ground, or climbing trees (to name just a few claw functions). This helps protect the claws against wear and tear.
Cheetahs are an exception to this rule…almost. These sprinters’ claws need to be at the ready at all times, so that they can take off at a moment’s notice (the claws help to keep them from slipping at high speeds). However, they’re still semi-retractable; even cheetahs need to rest up between heats.
Cats share this unique feature with a handful of viverrids (a family of animals often mistakenly identified as cats), including the African civet and the genet.
Unlike most big cats, a cheetah’s claws only partially retract.
By marko8904 () [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons, http://commons.wikimedia.org/wiki/File%3ACheetah_paws.jpg
Fact: Some hooves are really claws
A hoof is technically a nail that’s grown large enough to support an animal’s weight, but in even-toed ungulates—a group of animals that includes giraffes, antelopes, pigs (including warthogs), and even hippopotamuses—one half of the cloven hooves that define the group can be accurately referred to as a “claw.”
Fact: There are claws, and there are claws…
A standard claw will help a mammal, reptile, or bird (on which it’s called a “talon”) hunt, climb, dig, or defend itself. But there are specialized claws that serve only one purpose…or none at all! Protosimians, such as galagos (a.k.a. bushbabies) have what are known as toilet claws. Flattened, and duller than typical claws, toilet claws are used specifically (and exclusively) for grooming.
Dew claws are another type of claw, attached to vestigial digits. These claws aren’t in line with the others, and no longer touch the ground. Cats may use dew claws while attacking prey, but dog species, and many hooved animals, don’t use them for anything.
Bush Babies, like the one pictured here, use toilet claws for grooming.
Photo: Thomson Safaris guest, William Wolff