Today’s Wonder of the Day was inspired by Katrina. Katrina Wonders, “how many rhinos are left in the world” Thanks for WONDERing with us, Katrina!

Imagine you’re moving slowly 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. Now, though, only a few are 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 to treat illnesses. Some people think it cures many conditions, such as fever and stroke. However, rhino horn is composed of keratin. That’s the same stuff your fingernails and hair are made of. And like your fingernails and hair, rhino horn has no magical healing properties.

Nevertheless, people continue to kill rhinos for their horns. Rhino horn is very valuable. In some places, it can be sold on the black market for three times the price of gold, based on weight! It’s illegal to kill rhinos, but poachers still do so in order to take their horns. This 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. 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. This helps keep them safe from the poachers who might otherwise kill them for their valuable horns. However, this also leaves rhinos vulnerable to attacks from other animals.

Illegal poachers have decimated the rhino populations in Africa and Asia. Indian and black rhinos have been reduced to only a few thousand animals. 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. They say there are probably fewer than 100 Javan rhinos left in the world. Based on these numbers, rhinos are considered 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.

Have you ever seen a rhino at the zoo? If so, you know they’re pretty cute animals! Experts say it will take a lot of work to rebuild rhino populations in the wild. Are you up for the challenge?

Standards: NGSS.LS1.D, NGSS.LS2.A, NGSS.LS2.C, NGSS.LS4.D, CCRA.L.3, CCRA.L.6, CCRA.R.1, CCRA.R.2, CCRA.R.4, CCRA.R.10, CCRA.SL.1

Wonder What's Next?

Tomorrow’s out-of-this-world Wonder of the Day may make you hungry for a candy bar!