5 Questions with Liz Kalaugher, the author of “The Elephant in the Room”
When new diseases spread, news reports often focus on wildlife culprits—monkeys and mpox; bats and COVID-19; or waterfowl and avian flu. But it often works the other way around—humans have caused diseases in other animals countless times, through travel and transport, the changes we impose on our environment, and global warming. In The Elephant in the Room: How to Stop Making Ourselves and Other Animals Sick, Liz Kalaugher introduces readers to the wildlife human beings have harmed and the experts now studying the crosscurrents between humans, other animals, and health. We learn that military conflict likely contributed to the spread of rinderpest, or cattle plague, throughout Africa, devastating pastoral communities. That crowded poultry farms may create virulent new forms of bird flu that spill back into the wild. And that West Nile virus—which affects not only birds and humans, but other animals, including horses, skunks, and squirrels—will spread as global temperatures rise. Expanding today’s discussions of environmental protection to include illness and its impact, Kalaugher both sounds the alarm and explores ways to stop the emergence and spread of wildlife diseases.
How did this book come about?
When COVID-19 broke out in early 2020, I was traveling in Kenya to take part in the Great Grevy’s Rally, a biennial photographic survey of the endangered Grevy’s zebra run by the Grevy’s Zebra Trust. I’ve always been interested in wildlife conservation and I worried there’d be a backlash against bats, the likely source of the SARS-CoV-2 virus. So I decided to investigate the other side of the coin—how humans have been making other animals sick. I was surprised by how long and in how many ways human activities have spread diseases to wildlife. And by how much we can do about wildlife health that we haven’t yet chosen to act on.
What are some of the ways that humans make other animals ill?
In the early days, as we walked out of Africa and around the globe, chances are we took pathogens—disease-causing organisms—with us inside our bodies. Later, we transported animals, their diseases, and disease vectors (such as mosquitoes and fleas) worldwide by ship and plane. That enabled these pathogens to infect other animals in their target destination. The new victims may not have encountered the diseases before, potentially making them highly susceptible.
When we began farming animals and living more closely alongside them, we shared diseases with our new companions. And keeping animals with less genetic diversity than in the wild in crowded, stressful conditions also made them more susceptible to disease. Today, intensive poultry farming has created highly pathogenic forms of bird flu that have infected herds of cattle and their farmers in the US.
Then there’s habitat destruction. By chopping down tropical forests and disturbing other habitats, we’ve caused animals stress and forced them to live more closely together. That may have contributed to the spread of Ebola from fruit bats to apes, monkeys and small forest antelopes known as duikers.
Climate change contributes too, by forcing animals and plants to move to cooler regions, and mixing them up with other species. An encounter with a disease that your body hasn’t evolved immunity to is always dangerous.
Tell us about some of the species that have been impacted by illness in these ways.
By 1978 North America’s black-footed ferret was thought to be extinct, a victim of not one but two diseases. The ferret’s first disease problem arose when plague, which probably originated in China when our stores of grain attracted rodents, reached the West Coast. Most likely in the San Francisco area, a rat hopped off a ship arriving from Hong Kong and its fleas bit other rodents, transmitting the bacteria that cause plague.
The disease spread east through ground squirrels and other rodents. When it reached their territory, plague killed huge numbers of prairie dogs, the main prey of the black-footed ferret. (Prairie dogs were already in trouble in the Great Plains, where farmers poisoned these animals to protect cattle and ploughed their habitat to grow crops.)
Black-footed ferrets also faced the three Ps: ploughing of their habitat, plague, and poisoning of their food source. Soon it looked like they had gone extinct. But in 1981, John and Lucille Hogg’s dog on their farm in Wyoming killed an animal so beautiful that Lucille wanted to have it stuffed and the taxidermist recognised this black-footed ferret. A small colony of the animals had survived nearby but a second disease broke out—canine distemper virus. With only a handful of ferrets left, conservation workers took the remainder into captivity. Today a successful captive breeding program, along with treatment of prairie dogs for plague using peanut butter laced with an oral vaccine, means that around 300 black-footed ferrets are living free in the wild.
In New York City in the summer of 1999, American crows started to drop dead, followed by a bald eagle, snowy owl, flamingos, and cormorants at the Bronx Zoo. Humans also grew sick. It took a while to work out the cause as medical test kits diagnosed St. Louis encephalitis. Instead, the disease was West Nile virus, a related virus most likely transported to North America in an infected bird imported from Israel. As our climate changes, the virus will likely hold more territory.
And in 2013, endangered San Joaquin kit foxes living in Bakersfield, California succumbed to mange. Caused by a small mite, this disease has been spreading to new species and new locations and nobody’s quite sure why. Fortunately, treatments are readily available, though applying them to wild animals can be tricky; in Australia, researchers have come up with methods ranging from the simple “pole and scoop” technique—a cup filled with a parasite-killing liquid on the end of a pole so the person pouring the chemical on to the wombat’s back can stay some distance away—to an ingenious door flap over wombat burrows that applies parasiticide when the animals enter or leave.
Your book also introduces readers to conservationists working to mitigate disease. Who are some of these figures and what kind of work do they do?
It was a pleasure to talk to so many dedicated conservation workers and researchers as I wrote The Elephant in the Room. I wish I had space to include everyone in this answer but here’s a selection of those working with amphibians, mammals and birds.
In the late 1990s, Andrew Cunningham of the Zoological Society of London worked out that the chytrid fungus Batrachochytrium dendrobatidis (Bd for short) was devastating amphibian populations. So far, this fungus has wiped out the most species of any infectious disease—around 90 and counting. When Bd reached Montserrat in 2009, it spread across the Caribbean island in a wave. Cunningham took 50 mountain chicken frogs into a captive breeding program before the disease reached them, quite a feat considering that the frogs can leap eight feet high. He and his colleagues also bathed infected frogs with antifungal drugs, helping them survive. Today, the only mountain chickens on Montserrat are reintroduced and semicaptive, protected by drugs and heat treatments that kill the fungus, such as rocks to bask on, solar heating mats and corrugated steel sheets in their ponds.
In Brazil, Karen Strier of the University of Wisconsin-Madison is working to conserve the critically endangered northern muriqui or woolly spider monkey. Already threatened by habitat loss, the muriquis faced an outbreak of yellow fever in 2016. Since the outbreak, Strier has become an advocate of more hands-on conservation measures such as captive breeding or translocating animals. The professor aims to create a corridor that will connect two populations of northern muriquis in small patches of remaining forest.
In Hawaii, Dennis LaPointe of the US Geological Survey and his colleagues in the Birds, Not Mosquitoes consortium are looking to eradicate mosquitoes. The insects arrived as larvae in water casks on a whaling ship—when sailors drained the dregs into a stream, the insects gained a new home. Not long after that, thanks to the accidental introduction of bird diseases avian pox and avian malaria in the bodies of imported birds, much of Hawaii’s native birdlife disappeared. Today most of the islands’ original birds have either gone extinct or retreated to ground higher than 1500 meters, where it’s too cold for the mosquitoes that help spread these diseases. As climate changes, the mosquitoes will be able to survive at higher elevations. And that’s where Birds, Not Mosquitoes comes in. The team is releasing male southern house mosquitoes bred on the US mainland that carry a different strain of Wolbachia bacteria in their reproductive organs to the mosquitoes on Hawaii. When one of these new males mates with a local female, she’ll produce eggs that don’t hatch. This “incompatible insect technique” may one day enable the release of the ‘akikiki held in a captive breeding program, so that they can rejoin the five birds remaining in the wild.
What can we do—at either the individual or the policy level—to improve the health of wildlife and, inevitably, ourselves?
There is plenty we can do. As individuals, we can eat a more plant-based diet, take the train not the plane, and buy secondhand to reduce the pressure we put on Earth’s habitats and climate. Perhaps even more importantly, we can tell others about the different ways we’re harming wildlife health and ask our government representatives to enact policy measures to stem climate change, to regulate farming and the trade in wildlife and other animals, to protect the world’s forests, to stop subsidizing environmentally-damaging industries, and to make ecocide a crime in peacetime as well as war. These measures will make us all, human and non-human animals alike, safer. Prevention is always better than cure.
Liz Kalaugher is a science journalist and the coauthor of Furry Logic: The Physics of Animal Life. Her writing has appeared in BBC Focus magazine, the Guardian, New Scientist, and Physics World, among other outlets. She lives in Bristol, UK.
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