Which Animals Have the Longest Claws?

We really dug our claws into this Saturday’s Weird Animal Question of the Week, asked by Judy Eastwood: "What animal has the longest and shortest toenails?”

There isn’t much data on the subject, especially for shorter toenails, but we took a closer look at a few long-clawed animals that would not get a good night’s sleep in a waterbed.

Take the 3-foot (0.9-meter) long giant armadillo, whose largest claw measures nearly 8 inches (20 centimeters).

That means their claws are about 22 percent of their body length—probably the longest claw to body ratio of any living animal, Mariella Superina, chair of the International Union for Conservation of Nature's Anteater, Sloth, and Armadillo Specialist Group, says via email. (See "Diggers in the Dark: Discovering Giant Armadillos in Brazil’s Pantanal.")

For the sake of comparison, I’m 5’4,” and if I had the same proportions my nails would be a little over a foot (0.3 meter) long—which is probably why giant armadillos don’t type.

Native to South America, giant armadillos use their huge claws to dig up prey. They're “definitely not aggressive," but if threatened, they “could probably try to defend themselves with their foreclaws,” Superina says.

Digging It

Armadillos, like anteaters and sloths, belong to the superorder Xenarthra, which includes insect-eating, big-clawed animals from the American tropics, says Don Moore, associate director of Smithsonian's National Zoo in Washington, D.C.

The peaceful three-toed sloth hangs from rain forest trees with claws that can reach about 4 inches (10 centimeters). With its 23-inch (58-centimeter) body length, that gives them about a 17 percent claw-to-body ratio.

The bigger two-toed sloth, which is about 27.5 inches (70 centimeters) long, is 14 percent claw. (Also see "Bats and Sloths Don't Get Dizzy Hanging Upside Down—Here's Why.")

The giant anteater's four-inch (ten-centimeter) claws are “so long that they ‘knuckle walk’ on them,” Moore says.

Awkward gait aside, the claws are an excellent defense for the toothless anteater, which sometimes has to go toe-to-toe with powerful jaguars. (Also see "The Jaws That Bite, the Claws That Catch.")

Star-nosed moles aren't part of Xenarthra, but they're particularly noteworthy—or should we say noseworthy. The burrowing mammal is well known for its giant, star-shaped schnoz, but it has another claim to fame: The biggest claw of any mole.

Their claws are about 1/16th of their body length, or 6.5 percent, Moore says.

America's Got Talons 

When it comes to birds, the American harpy eagle, which ranges from Central to South America, is a major contender for longest talons—it has four-inch (ten-centimeter) long talons, says Bryan Bedrosian of the Teton Raptor Center.

And I’d definitely steer clear of the cassowary, the Australian native with a claw nearly 5 inches (about 13 centimeters) long.

On the other end of the spectrum, pygmy owls and elf owls may have the tiniest talons, Bedrosian suggested—not surprising, due to their size.

Oh, and me. I never could grow my nails either.

Weird Animal Question of the Week answers your questions every Saturday. If you have a question about the weird and wild animal world, tweet me, leave me a note or photo in the comments below, or find me on Facebook.