Hippos spark management debate

Nation’s most fearsome invasive species wreaks havoc on Western waterways.

 

On a warm Tuesday in March, Larry Sanders shades his eyes with a leathery hand and surveys the irrigation ditch that slices through his 500-acre farm in Colorado’s North Fork Valley. The ditch is running high and muddy with snowmelt; clumps of hay and the occasional red plastic cup spin lazily on its surface. I move to step onto the exposed clay bank, but Sanders plants his palm against my chest.

“Don’t move,” he hisses. “I’ve got him.”

He unslings the .308 bolt-action Remington and raises the scope to his eye. I strain to see what he’s aiming at, but I can’t discern anything in the murky water. The gun abruptly explodes beside me, Larry stumbling with the recoil, and the ditch erupts with spray and flesh – I catch a quick glimpse of a hulking, reddish-brown monster the size of a pickup truck, its vast red maw gaping and the twin scimitars of its curved lower tusks, each as long as my arm, flashing in the morning sun. The creature roars like a freight train, an unearthly bellow that resonates in the deep pit of my gut, and then it’s gone, vanished again into the opaque depths of the ditch. A cluster of bubbles breaks the surface and Sanders fires off a blind shot into the water, scans for telltale blood, but none rises.

“Missed the son of a bitch,” grumbles the farmer. “Again.”

I step away and lean over in the tall grass, my hands pressed against my wobbly knees. The echoes of the beast’s roar still reverberate in the valley. I glance fearfully at the ditch – already settled and placid, betraying no hint of the improbable creature that lurks within it.

Meet the West’s newest, most terrifying invasive species: Hippopotamus amphibious, the hippo.

***

No one’s quite sure when the hippos began turning up in Western waterways, nor how they arrived on this continent. Some believe the animals to be escapees, perhaps from a Zanesville-like private collection of exotic fauna. Others claim the animals were deliberately introduced as a prospective food source. (Although that plan may sound farfetched, it was nearly implemented by President Theodore Roosevelt in the early 1900’s.) Conspiracy theorists suspect that the 8,000-pound aliens were turned loose by conservationists who feared the loss of African mammals to poachers, and wanted to ensure that hippos would survive somewhere in the wild.

“With most invasions there’s an obvious origin – zebra mussels on hulls or in ballast water, or the shipment of flax seeds that contained tumbleweed,” says Mary Rabineaux, ecologist and invasive species expert at the University of Colorado-Boulder. “The fact that there’s no clear mechanism in this case makes the hippopotamus’ spread all the more remarkable.”

Indeed, the hippo takeover has been swift and thorough. The Yellowstone, Snake, and Columbia Rivers now support breeding populations, and, after a juvenile was sighted in the Gila River last month, scientists believe it’s only a matter of time before the creatures arrive in the main stem of the Colorado. Although hippos are exclusively freshwater dwellers in Africa, an individual captured in Utah’s Salt Lake was found to have incipient salt excretion glands below its eyes, suggesting that the invaders may be capable of rapidly evolving to their environs.

Yet it is within irrigation and drainage ditches — whose stagnant waters resemble conditions in slow, muddy African rivers — where hippos have truly flourished. That’s meant trouble for farmers like Sanders, who says he first spotted hippos in his ditch in May 2013 and has spent the last year trying, without success, to eradicate the immense pests. “Damn critters eat all my hay, tear up the creek banks, and keep me up all night with their ungodly noise,” Sanders complains. “And they shit everywhere.

Sanders’ problems pale in comparison to the damage suffered by Mark Ellis, a rancher in Montana’s Blackfoot Valley whose property was overtaken last summer. Bull hippos are famously aggressive, and Ellis has lost several of his valuable Black Angus cows to the territorial male that has established residence in his pond. “The poor cows must’ve went down to drink,” says Ellis. “I found the carcasses along the shore the next day. It was just… pure carnage.”

Ellis adds that because his state’s livestock compensation program only covers losses inflicted by wolves and grizzlies, he hasn’t been reimbursed for his cattle. Nationwide, hippo damages to crops, livestock and property have been estimated at $500 million.

Although the hippos haven’t yet killed any humans, wildlife experts believe it’s only a matter of time before a fatality occurs. In Africa, the behemoths are notorious for attacking boats, often seemingly unprovoked, and are responsible for nearly 3,000 deaths per year – far more than any other mammal. Although they’re generally more docile on land, they can reach speeds of up to 18 mph on foot, and have been known to pursue humans they perceive as threats.

“We’ve been incredibly fortunate not to have a fatal attack on a human yet,” says Leslie Derschowitz, a wildlife conflict specialist with the New Mexico Department of Game and Fish, who adds that avoiding rivers after dark and staying away from mothers with calves are the surest ways to avoid attacks. “Sometimes, though, you’ll get a bull just feeling grouchy that day, and there’s not much you can do besides get out of the way.”

The destruction of property and the threat to human life have the government scrambling for a solution. A pilot sterilization program in the Missouri River was stymied when tranquilizer darts proved incapable of penetrating the hippos’ thick hides, and the use of poisons has been prohibited for fear of impacts to other aquatic life. For now, scientists are still gathering information about the creatures’ habits: a team of U.S. Fish and Wildlife Service biologists recently fitted a so-called “Judas hippo” with a radio collar in hopes that it will lead them to larger population centers.

High Country News Classifieds
  • OPERATIONS DIRECTOR
    We are a Santa Fe-based nonprofit that builds resilience on arid working lands. We foster ecological, economic, and social health through education, innovation, and collaboration....
  • COMMUNITY ORGANIZER
    Come work alongside everyday Montanans to project our clean air, water, and build thriving communities! Competitive salary, health insurance, pension, generous vacation time and sabbatical....
  • CAMPAIGN MANAGER
    Oregon Natural Desert Association (ONDA), a nonprofit conservation organization dedicated to protecting, defending and restoring Oregon's high desert, seeks a Campaign Manager to works as...
  • HECHO DEPUTY DIRECTOR
    Hispanics Enjoying Camping, Hunting, and the Outdoors (HECHO) was created in 2013 to help fulfill our duty to conserve and protect our public lands for...
  • REGIONAL REPRESENTATIVE, COLUMBIA CASCADES
    The Regional Representative serves as PCTA's primary staff on the ground along the trail working closely with staff, volunteers, and nonprofit and agency partners. This...
  • FINANCE AND OPERATIONS DIRECTOR
    The Montana Land Reliance (MLR) seeks a full-time Finance and Operations Director to manage the internal functions of MLR and its nonprofit affiliates. Key areas...
  • DIRECTOR OF CONSERVATION
    The Nature Conservancy is recruiting for a Director of Conservation. Provides strategic leadership and support for all of the Conservancy's conservation work in Arizona. The...
  • EXECUTIVE DIRECTOR
    The Amargosa Conservancy (AC), a conservation nonprofit dedicated to standing up for water and biodiversity in the Death Valley region, seeks an executive director to...
  • BIG BASIN SENIOR PROJECT PLANNER - CLIMATE ADAPTATION & RESILIENCE
    Parks California Big Basin Senior Project Planner - Climate Adaptation & Resilience ORGANIZATION BACKGROUND Parks California is a new organization working to ensure that our...
  • CUSTOMER SERVICE ASSISTANT - (PART-TIME)
    High Country News, an award-winning media organization covering the communities and environment of the Western United States, seeks a part-time Customer Service Assistant, based at...
  • SCIENCE PROJECT MANAGER
    About Long Live the Kings (LLTK) Our mission is to restore wild salmon and steelhead and support sustainable fishing in the Pacific Northwest. Since 1986,...
  • HUMAN RESOURCES GENERALIST
    Honor the Earth is an affirmative action/equal opportunity employer and does not discriminate based on identity. Indigenous people, people of color, Two-Spirit or LGBTQA+ people,...
  • DEVELOPMENT DIRECTOR
    Colorado Trout Unlimited seeks an individual with successful development experience, strong interpersonal skills, and a deep commitment to coldwater conservation to serve as the organization's...
  • NEW BOOK BY AWARD-WINNING WILDLIFE BIOLOGIST, BRUCE SMITH
    In a perilous place at the roof of the world, an orphaned mountain goat is rescued from certain death by a mysterious raven.This middle-grade novel,...
  • DESCHUTES LAND TRUST VOLUNTEER PROGRAM MANAGER
    The Deschutes Land Trust is seeking an experienced Volunteer Program Manager to join its dedicated team! Deschutes Land Trust conserves and cares for the lands...
  • PROGRAM DIRECTOR
    Now hiring a full-time, remote Program Director for the Society for Wilderness Stewardship! Come help us promote excellence in the professional practice of wilderness stewardship,...
  • WYOMING COMMUNITY PARTNERSHIPS COORDINATOR
    The Theodore Roosevelt Conservation Partnership is seeking Coordinator to implement public education and advocacy campaigns in the Cowboy State to unite and amplify hunter, angler,...
  • ASSISTANT TOWN ATTORNEY
    Town of Jackson, Wyoming, $66,700 - $88,000 DOQ, full benefits. Law Degree Required. Rental housing options available. For a complete job description and to apply,...
  • MOUNTAIN LOTS FOR SALE
    Multiple lots in gated community only 5 miles from Great Sand Dunes National Park. Seasonal flowing streams. Year round road maintenance.
  • RURAL ACREAGE OUTSIDE SILVER CITY, NM
    Country living just minutes from town! 20 acres with great views makes a perfect spot for your custom home. Nice oaks and juniper. Cassie Carver,...