15 Things You Might Not Know About Rhinos

iStock.com/johan63
iStock.com/johan63

The rhinoceros is the second largest land mammal on Earth, next to the elephant. It's also one of the most aggressive. But despite its reputation as the bully on the playground, rhinos are vulnerable when it comes to one great danger: humans. Their ranks have drastically dwindled over the past century due to poaching and habitat loss, and conservationists are now trying to save them from extinction. In recognition of Save the Rhinos Day on May 1, here are 15 important facts about nature's knight in armor.

1. They're Greek—at least in name.

Rhinoceros in a field with a pond
iStock.com/davidevison

The word rhinoceros stems from the Greek words rhino (nose) and keras (horn). So when you shorten the word to "rhino," you're really just saying "nose."

2. A group of rhinos is called a "crash."

Three rhinos drinking water
iStock.com/Theo_Theron

Crash of Rhinos also happens to be an emo band from Derby, England.

3. They used to be 16 feet tall.

older rhino walking with two younger rhinos
iStock.com/CoreyFord

The paraceratherium, a hornless species of ancient rhinoceros that roamed the Earth 30 million years ago, stood over 16 feet tall. Modern rhinos are significantly smaller, of course, but scientists don't really know how they evolved. The white rhino, which grows up to 6 feet tall, is the largest of the five species that exist today. Measuring under 5 feet in height, the smallest is the Sumatran rhino, which is the only hairy species as well as the closest living relative of the extinct woolly rhinoceros.

4. White rhinos and black rhinos are actually the same color.

two rhinos standing in grass
iStock.com/fishcat007

They're both essentially grayish-brown. One widely spread rumor suggests that white rhinos were originally called wijd (wide) by Dutch settlers in Africa, referring to the animal's wide mouth, which was then mistranslated into English as "white." However, rhino expert Kees Rookmaaker has stated that there is no linguistic evidence to support that tale. It remains a mystery how the white rhino got its name.

5. Rhinos say mmwonk when they're happy.

Indian rhinos are known to make at least 10 distinct sounds, including honks (used during head-to-head fights), bleats (signaling submission), and moo-grunts (used between mothers and calves). Black rhinos use grunts as a greeting and make a mmwonk sound when they're content.

6. They have a complicated relationship with the oxpecker bird.

Oxpecker bird sits on the head of a rhino
iStock.com/Wolfgang_Steiner

Rhinos are often seen with oxpeckers hitching a ride on their backs, but the benefit of these birds is currently debated. The traditional argument is that they snack on bugs and ticks that crawl on the rhino's skin, but in 2000, research on cattle failed to find a consistent benefit to having oxpeckers, while a 2004 study on captive (and tick-free) rhinos found that rather than being helpful, oxpeckers spent much of their time picking at wounds and feasting on the rhino’s blood [PDF]. Meanwhile, other researchers argue that the birds actually do eat ticks and the like. The birds may give the rhinos one additional benefit though: A 2010 experiment found that without oxpeckers, black rhinos were able to detect a person walking up to a rhino 23 percent of the time. With the oxpeckers present that shot up to 97 percent, perhaps explaining why in Swahili, the oxpecker is referred to as the "rhino's guard."

7. They're long-distance sprayers.

rhino spray urinating
iStock.com/Marti Malet

In a show of dominance, alpha male Indian rhinos can spray urine a distance of over 16 feet. This is typically done in the presence of other males or breeding-age females. Other rhinos also spray urine: For males this is typically for marking territory, while female Sumatran rhinos [PDF] have been observed spray urinating 69 times in a 12 hour period before giving birth, and continued this behavior even after the calf was weaned, likely to mask the scent of the calf.

8. They communicate through poop.

rhino sniffing poop
iStock.com/krichie

White rhino droppings are unique identifiers, meaning that a rhino can take one whiff of a dung heap and instantly know the animal's age, sex, and reproductive status, according to one study. All white rhinos in a particular area head to the same spot to defecate, called a midden, which is essentially a communal dumping ground.

"We think of dung as just a waste product, but it's really a good way for animals to communicate," Courtney Marneweck, the head of the study, told National Geographic. "There's a lot of information there that we haven't taken advantage of."

9. Their farts smell like sulfur.

rhino sniffing another rhino's butt
iStock.com/1Photodiva

Rhinos are notorious for passing particularly noxious gas, according to the book Does It Fart? The Definitive Field Guide to Animal Flatulence:

"Rhino farts also smell really bad, so much so that they have even given rise to a piece of brewing terminology; when the yeast used to make alcohol through fermentation produces hydrogen sulfide it gives off a horrible sulfur smell, known as a rhino fart."

10. The males can get aggressive.

two male rhinos fighting with their horns
iStock.com/TonyBaggett

Rhinos aren't afraid to use their horns when it comes to matters of the heart. Male black rhinos are particularly aggressive in their pursuit of a mate, and the rate of "mortal combat" among these horned lovers is higher than any other mammal on the planet. About half of males and 30 percent of females die from injuries sustained while fighting.

11. They're related to zebras.

rhinos gathering with zebras
iStock.com/1001slide

The closest living relatives to rhinos are not elephants or hippos, but rather horses, tapirs, and zebras, all of which are classified as odd-toed ungulates. Rhinos and tapirs walk on three toes, while horses walk on one (which we know as a hoof).

12. They have sensitive feet.

rhino's feet
iStock.com/Kantapatp

Speaking of toes, rhinos do have one weak spot. Rhinos typically put most of their weight on their toenails when they walk to avoid wearing out their sensitive feet. This is easy to do in the wild, where marshes and mushy wetlands abound, but when they're brought to zoos, their toenails tend to wear down on hard surfaces like concrete and asphalt. This can lead to swollen, sore, and cracked feet, making them more susceptible to infection. To tackle this issue, one zoo glued modified horseshoes onto a rhino's toes, which you can read about in the book The Rhino With Glue-On Shoes.

13. They're wallowers.

But not because they're depressed. For a rhino, a nice mud bath is like a day at the spa. It not only helps the animals cool down in hot weather, but it's also great for their skin, helping to ward off pesky insects. Although the animals have a pretty thick dermis, they're surprisingly vulnerable when it comes to bug bites and sunburn.

14. Their horns are made of the same protein found in human fingernails.

close-up on a rhino's horns
iStock.com/alaincouillaud

Rhino horns are made up of nothing but keratin, but that doesn't stop poachers from killing thousands of the animals each year and selling their horns on the black market. The horns are fashioned into jewelry and figurines, and in some parts of Asia they're believed to hold healing properties (they don't).

15. They risk extinction.

man with binoculars in the wild
iStock.com/Peopleimages

Just a century ago, there were more than half a million rhinos around the world. Now, around 30,000 survive in the wild, largely due to poaching. All five species of rhino are in danger, but three are considered critically endangered: Sumatran, Javan, and black rhinos. Today, there are about 60 remaining Javan rhinos, fewer than 100 Sumatran rhinos, and about 5500 black rhinos.

There is some good news, though. Thanks to conservation efforts, black and white rhino numbers have increased in recent years, with the white rhino having been "brought back from the brink of extinction," according to the World Wildlife Fund. The organization Save the Rhinos is taking a multi-pronged approach to the issue, working to deploy more field rangers to protect the animals, reduce demand in Asia, and breed rhinos that are currently in captivity.

This story was republished in 2019.

The Biologists and Activists Fighting to Save Endangered Tapirs in Costa Rica

Stephanie Vermillion
Stephanie Vermillion

Costa Rican biologist Esteban Brenes-Mora was just 5 years old the first time he saw a tapir, and he immediately fell in love with the large, unusual animal. "The tapir was walking on the beach close to Corcovado National Park," he says of the moment that helped impact his future career. "It was a highlight for me; it led me to do what I do now."

Twenty-five years later, Brenes-Mora is a tapir expert and founder of Nai Conservation, a Costa Rican organization that is working to save the endangered species from its worst enemy: humans. Tapirs have been around for some 35 million years, but deforestation, highways through its habitats, and poaching have caused their numbers to drop significantly. It's estimated that the population of the Baird's tapir as decreased by more than 50 percent in just the last three generations. And in turn, what hurts the tapirs hurts the environment.

A Baird's tapir resting on a beach in Costa Rica's Corcovado National Park.
A Baird's tapir resting on a beach in Costa Rica's Corcovado National Park.
Stephanie Vermillion

"Tapirs are considered gardeners of the forests; they plant seeds and have a big impact on enriching the soil," Brenes-Mora explains. "The tapirs are even saving us from climate change. There's evidence from the Amazon that when tapirs are gone from certain forests, carbon sequestration in those forests decreases."

Experts have warned that tapirs, and specifically the Baird’s tapir that Brenes-Mora saw on that beach as a child, may soon be classified as critically endangered if current trends are not addressed.

Thankfully, Brenes-Mora has a plan.

 

I’m in Costa Rica on assignment to create an awareness-building film about the endangered tapir species. My colleague Alisha and I have just wrapped one week documenting the work of Nai Conservation, the local tapir research and conservation organization Brenes-Mora founded in 2015, and we're putting the final touches on our film in one of the most heavily tapir-populated (and protected) habitats, Corcovado National Park.

Of course, seeing a tapir in the wild would add an important element to our film, but even after a full week with the passionate, driven team behind Nai Conservation, we haven't seen even one.

This isn't surprising, though; few locals ever encounter the elusive tapir. The Baird's tapir—Tapirus bairdii, or known locally as danta in Spanish—is one of four tapir species in the region. It's indigenous to Central America and is a mammalian relative of the rhinoceros and horse, though it looks much more hog-like than either of the two (it has no relation to either boars or pigs). It is largely nocturnal and spends most of its day resting, hidden in the rainforests before foraging for fruits and berries in the afternoon. This makes spotting one in the wild even more rare, but Brenes-Mora and the Nai team want us to see a tapir as badly as we do.

Biologist Esteban Brenes-Mora is the founder of Nia Conservation.
Biologist Esteban Brenes-Mora is the founder of Nai Conservation.
Stephanie Vermillion

Before launching Nai, Brenes-Mora spent six months in Malaysia after getting his biology degree, working with RIMBA, an NGO studying tigers, flying foxes, and other native wildlife. But since seeing that tapir on the beach when he was young, it had been his childhood dream to work with tapirs, and a fellowship with the Zoological Society of London gave him that chance. According to Brenes-Mora, the fellowships are meant to provide early-career conservationists and biologists an opportunity, through funding and mentorship, to get a foothold in their desired field. For him, that meant tracking tapirs through the highlands of Costa Rica's Talamanca Mountains.

One day in 2015, Brenes-Mora and a friend reached Cerro de la Muerte—Costa Rica's "mountain of death," the highest point on the mountain range. They were discussing creating a logo for the fellowship project, but Brenes-Mora’s friend saw longer-term potential.

"He was like 'whoa, you have more than a logo, you have more than a project, you can actually start something here,'" Brenes-Mora remembers.

And start something he did. The idea quickly evolved into the full-scale conservation project, Nai. (In the indigenous Bribri language of Costa Rica, nai means danta, or tapir.) Under Brenes-Mora's leadership, the organization is bringing together people with a variety of skills to raise awareness and preserve the tapir species. Nai's biologists and veterinarians perform critical, in-the-field research that informs tapir conservation action. The organization's teachers educate children on the tapir species as part of its "Salva-Dantas" program, which prepares youth for a lifetime of helping the tapir. And graphic designers and artists like Mauricio Sanabria, an artist who joined the team as a twentysomething in 2017, create eye-catching signs and other content to help spread the word about Nai—and ultimately the tapir—online and across local communities.

Over the past four years, this seed of a project has grown into a grassroots movement. The team's bright yellow "tapir crossing" stickers—the symbol of support for Nai—are popping up in restaurants, homes, and businesses throughout the country. One delicious example is in Costa Rica's capital city of San José, where Lucía Cole and Mauricio Varela, the founders of Tapir Chocolates, donate a portion of all profits to Nai.

And all the way down in the southwestern-most Osa Peninsula some 200 miles away, two of Nai's biggest supporters, Steven Masis and Deyanira Hernández, plan to guide us through the jungle in search of a tapir.

The founders of Tapir Chocolates donate a portion of their profits to Nai to aid in the conservation of Costa Rica's Baird's tapirs.
The founders of Tapir Chocolates donate a portion of their profits to Nai to aid in the conservation of Costa Rica's Baird's tapirs.
Stephanie Vermillion

Masis and Hernández lead wildlife tours across the tropical Osa Peninsula, including through the country's popular, secluded Corcovado National Park. Both in their early thirties and with backgrounds in biology, Masis and Hernández join Nai and its partners on virtually all research trips through the remote, 160-square-mile park. Of all the places to spot tapirs in Costa Rica, Corcovado's dense, foggy rainforests—accessible only by boat or tiny plane—are the best bet. But even with their exceptional tapir-sighting success rate, these two activists don't take those sightings for granted.

Any encounter with the endangered tapir is rare and special. Due to threats like poaching (its hide is highly valuable on the black market), habitat loss, road kills, and trafficking, populations are plummeting throughout its Central American habitat. At this point, Brenes-Mora estimates only 1500 tapirs remain in Costa Rica, and research suggests that the total population of Baird’s tapirs in the entire region is only around 3000.

The possibility of losing the tapir species is problematic for planet Earth. The tapir holds a unique ecological "superpower" that’s becoming more important by the second: the ability to help combat climate change. They can eat over 200 pounds of fruit, plants, and seeds a day, and in the process, they essentially clear the forest floor, till the ground with their rummaging, and spread the seeds that they eat through transference and droppings. And they've been doing this for millions of years.

 

Despite the challenges, the tapir movement is not all doom and gloom. Earlier that week, I joined Nai for an afternoon installing "tapir crossing" road signs in central Costa Rica's Cerro de la Muerte mountains, and saw several indicators of success throughout the day.

For one, even erecting these street signs is progress. The team used trap-photo data and subsequent tapir and road traffic models to project exactly where traffic accidents occur most frequently, and they have used that data to convince the transportation department and local communities to allow tapir-crossing signs at high-risk sections along the busy Inter-American Highway, which runs right through tapir habitat.

The Nai Conservation team installs tapir crossing road signs in Costa Rica.
The Nai Conservation team installs tapir crossing road signs in Costa Rica.
Stephanie Vermillion

"All of our decisions are based on actual data," Brenes-Mora says. "Based on that data, we start making decisions and lobby to include our ideas into policy.”

Brenes-Mora, a pragmatic biologist who has formed strong working relationships with key government leaders and NGOs, is hesitant to claim the decrease in road kills as a success just yet. A couple of years is not enough time to impact the population of a large mammal, he says (especially one with a 400-day gestation period for a single calf—repopulating the species will take a very long time).

But four years is enough time to create a widespread, engaging movement among locals. From Brenes-Mora's perspective, this unity surrounding the tapir is the ultimate success.

"Without people, it doesn't matter if we have protected areas, it doesn't matter if we're protecting the populations," he says. "Without engaging people, we won't be able to secure the species in the long term."

While Nai is his brainchild and tapirs are his lifeblood, Brenes-Mora doesn't want the future of Nai—or, more importantly, the tapir species—to depend solely on him.

"I'm always asking myself 'what will happen when I die?'" he muses. "I don't want tapirs to be unattended if something happens to me. I don't want to be the tapir guy, I want Nai to be the tapir group. I want all the members of the team to be the tapir people. It's hard to do that, but we're on the right track."

With the future in mind, Brenes-Mora is priming people like Nai research lead and team veterinarian Jorge Rojas, artist Mauricio Sanabria, and dozens of other dedicated team members to help carry the tapir mission forward. They tour and give talks, like at a recent weeklong event they hosted at the University of Costa Rica with the Costa Rica Wildlife Foundation, where Brenes-Mora and Rojas spoke at a symposium for students, professors, and activists about threats to tapirs, their importance to the environment, and how to best help and protect them.

That's why our trip down to Corcovado National Park is a milestone for the movement—the plight of the tapir is generally less known than that of the whale or tiger or rhino. Raising awareness about the tapir is one of its best chances at survival.

 

Alisha and I had originally planned to take the two-day Corcovado trek on our own, but after some consideration (and likely Brenes-Mores's urging, given the rough terrain we'd be facing—i.e. jungle off-roading), Sanabria joined us for a chance to see the animal he's been working so hard to save. For all the work he has done as a researcher and activist and the time he's spent in the field, he has yet to see a tapir in the wild.

Suddenly, our naturalist guide bursts from the forest yelling, "Un tapir! Un tapir!," and Sanabria takes off running. Despite the fact that Masis and Hernández see tapirs more regularly than most, they're leading our 100-yard blitz down the beach with him—smiling their "Christmas morning grins" every step of the way.

Finally, after much huffing and puffing, we've made it. We've caught up with our guides and are now face to face with the remarkable tapir we drove hundreds of miles to see.

Nai Conservation researcher and activist Mauricio Sanabria with a tapir on the beach in Costa Rica's Corcorvado National Park.
Nai Conservation researcher and activist Mauricio Sanabria with a tapir on the beach in Costa Rica's Corcorvado National Park.
Stephanie Vermillion

We're awestruck and on adrenaline highs, but the tapir couldn't be less interested in the five of us. He offers a polite nod between super-sized mouthfuls of vegetation, but he has business to attend to—like strolling along the shoreline, urinating in the ocean, and then passing out in the sun.

Sanabria locks eyes with the now-sleepy tapir, and in a moment of near-solitude with the elusive creature, Sanabria can feel the magnitude of the work he's been doing.

"It's touching to finally see what you're working for," he says. "It's a little sign of hope."

A Baird's tapir on a beach in Costa Rica's Corcovado National Park.
A Baird's tapir on a beach in Costa Rica's Corcovado National Park.
Stephanie Vermillion

Is There An International Standard Governing Scientific Naming Conventions?

iStock/Grafissimo
iStock/Grafissimo

Jelle Zijlstra:

There are lots of different systems of scientific names with different conventions or rules governing them: chemicals, genes, stars, archeological cultures, and so on. But the one I'm familiar with is the naming system for animals.

The modern naming system for animals derives from the works of the 18th-century Swedish naturalist Carl von Linné (Latinized to Carolus Linnaeus). Linnaeus introduced the system of binominal nomenclature, where animals have names composed of two parts, like Homo sapiens. Linnaeus wrote in Latin and most his names were of Latin origin, although a few were derived from Greek, like Rhinoceros for rhinos, or from other languages, like Sus babyrussa for the babirusa (from Malay).

Other people also started using Linnaeus's system, and a system of rules was developed and eventually codified into what is now called the International Code of Zoological Nomenclature (ICZN). In this case, therefore, there is indeed an international standard governing naming conventions. However, it does not put very strict requirements on the derivation of names: they are merely required to be in the Latin alphabet.

In practice a lot of well-known scientific names are derived from Greek. This is especially true for genus names: Tyrannosaurus, Macropus (kangaroos), Drosophila (fruit flies), Caenorhabditis (nematode worms), Peromyscus (deermice), and so on. Species names are more likely to be derived from Latin (e.g., T. rex, C. elegans, P. maniculatus, but Drosophila melanogaster is Greek again).

One interesting pattern I've noticed in mammals is that even when Linnaeus named the first genus in a group by a Latin name, usually most later names for related genera use Greek roots instead. For example, Linnaeus gave the name Mus to mice, and that is still the genus name for the house mouse, but most related genera use compounds of the Greek-derived root -mys (from μῦς), which also means "mouse." Similarly, bats for Linnaeus were Vespertilio, but there are many more compounds of the Greek root -nycteris (νυκτερίς); pigs are Sus, but compounds usually use Greek -choerus (χοῖρος) or -hys/-hyus (ὗς); weasels are Mustela but compounds usually use -gale or -galea (γαλέη); horses are Equus but compounds use -hippus (ἵππος).

This post originally appeared on Quora. Click here to view.

SECTIONS

arrow
LIVE SMARTER