As you cross through the dense forests of tropical Africa, you search high and low for a large, rare mammal. Thousands of these animals used to inhabit these parts, but now there are only a few left. What are we talking about? The rhinoceros, of course!

The rhinoceros — often called the rhino — gets its name from its defining feature: its horn (or horns). The word rhinoceros comes from the Greek words for nose (rhino) and horn (ceros).

For hundreds of years, rhino horn has been used by people around the world, especially in Asia, to treat illnesses, such as fever and stroke. However, rhino horn is composed of keratin. That's the same stuff your fingernails and hair is made of. And like your fingernails and hair, rhino horn has no magical healing properties.

Nevertheless, rhinos continue to be killed for their horns. Rhino horn is so valuable that in some areas of the world it can be sold on the black market for three times the price of gold! Illegal poaching is one of the primary reasons that rhinos are so rare today.

There are five types of rhinos. White and black rhinos are native to eastern and southern Africa. Greater one-horned rhinos can be found in northern India and southern Nepal. Sumatran and Javan rhinos can be found only in small areas of Vietnam, Malaysia, and Indonesia.

Javan and greater one-horned rhinos have only one horn, while the other types have two horns. In some areas, rhinos are being dehorned to prevent illegal poachers from killing them. Their horns are removed, leaving them alive and healthy and free from the poachers who might otherwise kill them for their valuable horns.

Illegal poachers have decimated the rhino populations in Africa and Asia. Indian and black rhinos have been reduced to only a few thousand animals, while white rhinos may exist in numbers in excess of 7,500.

Sumatran and Javan rhinos are the rarest. Scientists believe there are 400 or fewer Sumatran rhinos and probably less than 100 Javan rhinos left in the world. Based upon these numbers, rhinos are considered to be critically endangered today.

Rhinos have a reputation for having a bad temper. Some believe they can be mean and vicious. Given their dwindling numbers and constant attacks by poachers, it's no wonder they might be angry!

However, this view of rhinos is a bit of a misunderstanding. Rhinos have poor eyesight. Because they are very nearsighted, they can be startled easily. When startled, they will often charge, fearing an attack.

Rhinos do not attack other animals or humans for food. These large mammals are herbivores that mainly eat grasses or leaves. Rhinos that live in zoos feed on hay and fruits and vegetables, such as carrots and apples.

Think you can distinguish between a black rhino and a white rhino? Sounds easy, right? Not so fast! They're both the same color: a dull brownish gray. You can tell them apart by looking at their mouths.

White rhinos have wide mouths (some scientists think the name “white" came from their “wide" mouths!) that help them graze on grasses. Black rhinos have narrow mouths with lips that help them pull leaves and shrubs into their mouth.

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