I used to think hippopotamuses were like elephants, protected from being slaughtered and pillaged by humans. I used to think the United States didn’t have much to do with hippos. And I used to think it would be fairly difficult to acquire a good pair of hippopotamus-skin boots for under $1,000. 

I was wrong on all three counts.

While China has a big reputation for buying and selling exotic and endangered animals — especially after two years of news about a virus that likely jumped from animals to humans in that country — the United States actually plays a huge role in international animal trade. By one count, we were the number-one importer of endangered-animal products in the world between 1998 and 2018. And hippos are no exception. According to data from the organization that regulates and tracks the legal trade of endangered species, the United States is often the biggest market for hippopotamus parts — yes, as in body parts.

Thousands of bits and pieces of hippo skin, teeth, bones and bodies are imported to this country every year. The situation has gotten so bad that last month the Humane Society of the United States, two of its affiliate organizations and the Center for Biological Diversity submitted a petition to the U.S. Fish and Wildlife Service to add hippopotamuses to the list of species protected under the Endangered Species Act. (USFW has to respond to the petition by June 22.) There are no wild hippos in the U.S., but Americans’ shopping habits affect their fate. 

If this feels like an absolutely bizarre set of facts, you aren’t alone. I was surprised to learn about the U.S.’s role in the hippo-parts trade, and set out to figure out how Americans could be legally importing so much — and why. What I found were not just answers to those questions but also a broader understanding of how we protect endangered species. Even though a hippo’s body parts are less desirable than those of other exotic species, it’s still in demand, killed and sold because it’s less rare.

Hippopotamuses are not wilting flowers, delicately swooning as humans pick them off. If anything, said Rebecca Lewison, director of the Institute for Ecological Management and Monitoring at San Diego State University, direct conflict between humans and hippos is often the other way around — the hippos are the ones who do the killing. “It’s as if the wolves could team up and take revenge,” she said.

That aggression makes hippos different from some of the world’s other charismatic megafauna, and so do human perceptions about the quality of their body parts. Hippos have curved, rough teeth covered in grooves. They have thick, tough skin that carries the scars of past fights. They don’t lend themselves naturally to either the ivory trade or to interior decoration. Instead, their biggest threat is the slow loss of habitat to humans who compete for the same waterways and riverbanks, Lewison said.

That habitat loss has earned hippos endangered status under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (commonly known as CITES), a treaty agreement and the organization that helps to regulate and track legal trade of listed animals. But while the animal’s numbers are trending downward globally, hippos can be plentiful within their current habitats. A nuisance animal, even. “In any one area, if I told people, ‘We’re worried about hippos,’ they’d be like, ‘Lady, you’re insane. Have you looked behind you?'” Lewison said.

This is the strange position of the hippo as an endangered species. It is not beloved at home. Its ivory is seen as unattractive and hard to carve, its skin unfashionably rough, said Crawford Allan, the wildlife crime lead at the World Wildlife Fund. Unlike elephants or tigers, there’s no massive wave of international demand that sends poachers out in search of supply.

And yet, some people still can’t get enough. Under CITES, endangered species can still be bought and sold legally. With a high-risk animal like most elephants, that sale can happen only under very particular circumstances — like an animal for breeding or a specimen for science. But hippos are listed under a different classification for species that are endangered but not endangered endangered. With hippos safe from the immediate threat of extinction, all you need to buy and sell their parts is documentation on one end proving that exporting the animal product won’t be detrimental to the species, and documentation at the other end proving the import arrived legally. And lots of hippo parts are being bought and sold.

The numbers tracked by CITES as part of its regulatory powers show that between 2015 and 2019 — the most recent years we have good data for — hippo-exporting countries reported shipping out 5,169 hippo-leather products,¹ 4,184 hippo skins (plus another 3,675 skin pieces), 2,516 hippo-hunting trophies and more than 11,500 teeth. Those are just the largest categories of legal trade; a lot of other parts are being exported as well.

In most recent years, the bulk of all those parts have been heading for the United States. That's why Tanya Sanerib, the international legal director of the Center for Biological Diversity, is pushing to get the hippo listed under the Endangered Species Act. Doing so would restrict imports of hippo parts to this country, and while that wouldn't eliminate hippo trade, it would drastically reduce demand for legal hippo parts.

In four of the five years of CITES data we looked at, exporting countries reported that the U.S. was the destination of more than 50 percent of their hippo exports.² Listing hippos under the Endangered Species Act would also make it easier for U.S. authorities to identify and seize illegally traded hippo parts. This strategy — restricting trade within the country of highest demand — is essentially the same one that the World Wildlife Fund credits with drastically reducing the global trade in African elephant ivory. Once by far the world's largest importer of ivory, China banned elephant ivory trade at the start of 2018, driving down demand in that country and aiding the global reduction in elephant poaching.

CITES data doesn't reflect illegal trade, Sanerib said. But the legal trade helps to drive demand, which affects illegal markets as well. And what hippo parts are Americans buying in those legal markets? Skin, mostly. Hippo leather, skin and skin pieces accounted for 71 percent of specimens that exporting countries reported sending to us. Allan suspected at least some of that was ending up in the exotic boot business. "Some people like to have a different pair of boots for a different day of the week, and they like a different type of leather," he told me. Hippo boots aren't the prettiest things, he told me. They're dark and scarred — "rugged," is how he described it. But if you get yourself a different pair of exotic boots each Christmas, hippo might go well on a shelf beside boots made of alligator, stingray or sea bass leather.

While researching hippo products before our interview, Allan had inadvertently told his search-engine cookies that he himself was in the market for exotic footwear. As I talked with him, he pulled up the FiveThirtyEight website and was presented with an algorithmic ad … for hippo boots. "El Dorado men's hippo chocolate boots for $760," he said. "And you compare that to a men's stallion alligator boots for $1,460 or sea-bass-leather boots for $280. So, you know, it's sort of a mid-range in value."

Experts also told me that a lot of the hippo skin being used in the U.S. probably isn't even being marketed as anything special. Endangered animals end up in the fashion supply chain by accident, said Monique Sosnowski, a graduate student in criminal justice at the City University of New York who studies endangered-wildlife trade in the fashion industry. That's because of a lack of oversight as products move from one country to another and to a third. Export numbers and import numbers seldom exactly match in CITES data, and even things that are counted properly aren't always being sold to customers under a flashing sign marked "HIPPO." Something could end up mislabeled — accidentally or deliberately — at a lot of different steps in the process from animal's back to human's closet.

Wallets and small leather goods are an example of a place where this can happen. Mexico has an extensive leatherworking industry, Allan told me. That's the country where raw hides of all kinds will often go to get tanned and processed and turned into usable products. In fact, according to Mexico’s export data, 76 percent of its hippo-leather products³ were sent to the U.S. There are a lot of points in the chain where hippo leather might just become "leather" by the time you're buying it as a wallet.

But if hippo parts really are considered so inferior compared with other exotic animals, why do they keep getting sold? Mostly, it's because hippos are there and they're convenient, said Sanerib. It's easier to trade hippos than it is to trade elephants. Hippos aren’t perfect, but they’re available. Even when other things aren’t.

CORRECTION (May 2, 2022, 11:30 a.m.): This article has been updated to correct the misspelling of Crawford Allan’s last name.