The true story of the Louisiana hippos

The hippopotamus is arguably one of the great physical comedians of the animal world. With its roly-poly body, Shrek-like ears and squat nostrils smushed into a giant snout, it's easy to forget that the absurd-looking creatures are actually quite dangerous to humans. According to the BBC in 2016, hippopotamuses killed an average of 500 people each year in Africa — far more than lions, which tend to inspire far more fear. Theodore Roosevelt himself understood this, and as such was understandably pleased when he managed to kill eight hippos during his famous 1909-1910 safari.

This article first appeared in Salon

Yet around the same time that Roosevelt was traipsing through Africa and slaughtering these rotund mammals, other Americans were planning on bringing hippopotamuses to their own country.

Not as zoo exhibits, mind you. The plan was to introduce wild hippopotamuses to the Louisiana bayous, with the idea that they would some day be as common a feature in that region as alligators and pelicans.

If this sounds crazy, you're right, but the two main proponents of the scheme had a method behind their seeming madness. Rep. Robert Broussard, D-La., was concerned about how a plant known as pontederia crassipes, or the common water hyacinth, was choking off waterways and killing the fish (by soaking up oxygen in the water) that lived in the bayous he loved so dearly. At the same time, Broussard was, like many other Americans, concerned about a meat shortage afflicting the country. He came up with a simultaneous solution to both problems that seemed ingenious: Import hippopotamuses to the Louisiana bayous, where they would eat the hyacinths and be hunted for their tasty flesh. (Per Mental Floss, hippopotamus meat tastes "mild, less than lamb and more than beef, slightly more marbled than usual venison.")

"The immediate impact would probably have been fairly minor," at least initially. But over time, it would have "become an environmental catastrophe."

Broussard didn't act alone. When he introduced the so-called "America Hippo Bill" in 1910, he recruited two notable expert witnesses: Frederick Russell Burnham, a frontiersman who enthusiastically participated in African colonialist adventures and served as an inspiration for Indiana Jones, and Fritz Duquesne, a South African Boer who regularly hunted big game like hippopotamuses. In addition to Burnham and Duquesne, Broussard also recruited an apple expert named William Newton "W. N." Irwin, a well-respected veteran of the Department of Agriculture.

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Broussard's proposal, as backed by all three men, was straightforward: Congress should allocate $250,000 to go to Africa and bring hippopotamuses from that continent to the United States. As Irwin put it at the time, "It is a kind of a combination of pork and beef in taste," and as such could help Americans who had run out of meat due to the overgrazing allowed by the meat industry barons on rangeland.

For a while it seemed like this plan might come to fruition. It had the support of both The New York Times and Roosevelt (still influential despite being a former president), and reportedly came just one vote shy of being passed. Though Burnham and Duquesne both hated each other and had even recently been under orders to assassinate each other (they were also spies), they publicly put aside their differences because they felt so strongly about the hippo importation cause. Apparently cooler heads prevailed — not because of the obvious ecological problem that would be caused by introducing another invasive species into the bayous, but because people were generally put off by the idea of the South being potentially overrun by hippopotamuses.

Yet would that have actually happened?

"Despite the assurances of the three colorful 'experts' brought in to testify to congress at the hearing in 1910, it's not at all clear to me that hippos would thrive along the Gulf Coast," Michael Massimi, Invasive Species and Marine Programs Coordinator at the Barataria-Terrebonne National Estuary Program, told Salon by email. Massimi pointed out that, given how Africa is much warmer than Louisiana, "I think winters in coastal Louisiana might be a bit cold for them." In addition, the delta region does not have the hard ground found in the areas of Africa where hippopotamuses flourish, and indeed "much of the area would be like quicksand to a hippo."

At the same time, this doesn't mean that the plan was bound to fail.

"I suppose it would depend in large part on how many individuals would have been brought over as the founder population," Massimi explained. "I'd put the odds around 50/50 that they'd take to this part of the New World." However, even if they avoided being wiped out, Massimi isn't entirely sure they would have totally transformed their environment — at first.

"Let's say they survived their first few winters and were able to reproduce in coastal Louisiana to a point where a naturalized population was maintaining itself," Massimi told Salon. "The immediate impact would probably have been fairly minor. Louisiana's coastal wetlands were unimaginably vast in 1910, and the hippo reproduces slowly. A few small herds here and there might have resulted in some damage to marshes and attacks on unlucky fishermen, but probably no large-scale impacts, at least initially."

Yet over time, he says, the hippos' presence would "become an environmental catastrophe."

It isn't difficult to imagine why. After infamous drug lord Pablo Escobar was gunned down by authorities at his palatial estate in Colombia, authorities decided that it would be too logistically difficult to move his pet hippopotamuses to nearby zoos (which they did for the rest of his menagerie of exotic animals). Instead they simply allowed them to stay — and, as animals are wont to do when left unsupervised, they began to breed. By 2020, there were roughly 50 wild hippopotamuses in Colombia, and some experts believe that number will rise to anywhere from 400 to 800 hippopotamuses by 2050.

There have been adverse consequences to this development. Because hippopotamuses produce roughly 13 pounds of fecal waste every day, their excrement has clogged up rivers and choked off nutrients needed by other wildlife. (Even in their native Africa, hippopotamus excrement is causing water issues due to climate change.) Local Colombians also grew attached to the hippopotamuses, which made population control difficult; after a popular male hippopotamus known by locals as "Pepe" was culled, animal rights activists successfully took the hunters to court and made it illegal to kill the animals as a means of population control.

Yet there are some scholars who argue that introducing large-bodied mammals to these types of ecosystems could have positive effects. In a 2020 study led by researchers from the University of Technology Sydney on the impact of introducing large herbivores to new ecosystems, the scientists wrote that "while the ecological effects of hippos in South America remain unknown, their trait combinations suggest that their effects may overlap with extinct species in certain ecosystem components (e.g., grazing and disturbance in riparian zones) and diverge elsewhere (e.g., direction and rate of nutrient transport)."

"Hippos probably would not have put a dent in the water hyacinth problem... The water hyacinth is an invasive pest plant in Africa too, and the hippos only occasionally munch on it. So the other half of the very premise of bringing them here in the first place was faulty."

Massimi, for his part, is pessimistic about the theoretical impact of hippopotamuses in Louisiana.

"Judging by the scorched earth effects of two other invasive species in coastal Louisiana, I'd say we could have ended up with a huge problem on our hands," Massimi argued. "Effects from the nutria, introduced in the 1930s to bolster the fur trade, show what herbivory can do to coastal marshes." Massimi also noted how "feral hogs, having arrived in coastal Louisiana more recently, show what trampling, wallowing, and rooting can do." If there were hippopotamuses in Louisiana, they would likely "insult the wetlands much more severely in both these ways, and probably in additional ways that we can't even guess, such as nutrient loading, or transforming coastal forests to marshes and marshes to mudflats. And back then, there were no environmental regulations to protect coastal habitats. There were no control programs. Hippos might have destroyed the coastal wetlands, which, by the way, is the primary hurricane protection system for everyone who lives in coastal Louisiana, before humans even developed the wherewithal to realize what was happening. Much less to respond effectively."

After adding the caveat that hippopotamuses might have been easier to control because of their size and slow reproduction rate, he pointed out that they likely would not have even succeeded in eating the hyacinths that so troubled Broussard.

"Hippos probably would not have put a dent in the water hyacinth problem," Massimi told Salon. "Their habit is to spend the sunlight hours in the water, but come out of the water at night to graze on land. The bulk of their diet is terrestrial grasses. The water hyacinth is an invasive pest plant in Africa too, and the hippos only occasionally munch on it. So the other half of the very premise of bringing them here in the first place was faulty."