What's the difference between a wallaby and a kangaroo?

Kangaroos and wallabies differ in several ways. See more pictures of marsupials.
Geoff Dann/Dave King/Getty Images

If you're like most people, when you think of kangaroos and wallabies, you think of Australia -- pouched animals with prominent hind legs, bouncing around the countryside like kids on pogo sticks. Or perhaps you flash to your favorite marsupial characters -- Rocko from "Rocko's Modern Life" or Kanga, friend to Christopher Robin and Winnie the Pooh. Or do you think of Captain Kangaroo?

Marsupial Image Gallery

Regardless of your associations, you've probably wondered what distinguishes one animal from the other. After all, they look so much alike. They're both marsupials, meaning mothers carry their young around in built-in pouches. And scientists have even grouped them into the same order, family and subfamily.

Don't let the name fool you: Captain Kangaroo is in fact a human being. Don't let the name fool you: Captain Kangaroo is in fact a human being.
Don't let the name fool you: Captain Kangaroo is in fact a human being.
Lisa Larson/Time & Life Pictures/ Getty Images

So what's the difference? Is Rocko a wallaby or a kangaroo?

The most obvious difference between the wallaby and the kangaroo is size. As a rule, the kangaroo is generally much larger than the wallaby. The kangaroo has more height between its ankles and knees, which makes its legs seem out of proportion to its body. The kangaroo's legs are built for speed on open terrain. The wallaby's more compact legs are built for agility in forested areas. Although there are many different species of both wallabies and kangaroos that span a wide range of sizes, wallabies only tend to weigh between four pounds and 53 pounds (2 kg to 24 kg) and grow a mere 12 inches to 24 inches (30 cm to 104 cm) tall, not including their tails [source: "Wallaby"]. Kangaroos, on the other hand, can grow to heights of 8 feet (2.1 meters) and weigh as much as 200 pounds (91 kg) [source: Microsoft Encarta].

Another simple way to tell a wallaby and a kangaroo apart is by their coloring. A wallaby's coat is usually brighter with two to three different colors. For example, the unfortunately-named "red-necked" wallaby's grayish body is distinguished by reddish markings around its shoulders. The kangaroo's coat is usually less splashy and more uniform, with muted colors like brown or gray.

For a more scientific way to tell the two animals apart, you'll have to get these guys to open their mouths and say "Aaaah." On the next page, learn how a quick look at the kangaroo's and wallaby's teeth could help you identify them.