PREFACE

Dung Beetles
and the Girl
on the Airplane

Our single-prop four-seater plane made a low swoop over the short runway, sending the gangly giraffes, monkeys, and impala loping and leaping over the red dirt into the shelter of the trees in the wooded grassland. In the days that followed, from our safari truck, we saw lion cubs and lionesses playing, kitten-like, in the shadow of our vehicle. We were charged by a huge female elephant, her ears fanned out wide to the sides. “She’s bluffing. Sit still,” said the guide. We froze. She stopped suddenly, twenty meters away, turned, and walked slowly back to rejoin her family. We thawed in the slow heat. Over gin and tonic, we watched the hippos lolling in the river; we heard them grunting and crashing past our cabin at night. We glimpsed the hyenas retreating into the darkness as our Maasai guide, lantern and spear in hand, led us back to our cabin after dinner. Bee eaters — bright flashes of green and white and black — darted and swooped into and out of small caves in the earthen cliffs along the river as our boat cruised past. Storks, stilts, spoonbills, and sandpipers trod daintily in the shallows.

Several days into our safari retreat, in the baking late-morning heat, ten of us followed two guides through green-streaked, straw-colored grasses, between ash-gray tree skeletons, flat-topped Terminalia spinosas (those classic African trees that photograph so well against the setting sun), and gnarled, deep green shrubs. It was the dry season in the Selous Game Reserve in Tanzania, the most astounding and exuberantly diverse wildlife park in all of Africa. Almost everyone else in our group was on the lookout for more elephants, lions, Cape buffalo, and warthogs, and nervously excited about the possibility of encountering them without the benefit of an escape vehicle. The effect was enhanced by the fact that Mpato, one of the guides, was carrying a rifle big enough to bring down a large, angry beast, should that be necessary.

To the dismay of the others on our walkabout, I had also corralled the guides into helping me find animal scat. What kind of an idiot comes to Africa to look at shit? Well, I’m a veterinarian, so maybe it fits.

A small white pile of feces, away from a lake-sized widening in the Rufiji River, was probably hyena. The white indicated a carnivore, the crushed bones of its prey bleaching in the hot sun. A similar whitening (and hence carnivore) pile closer to the lake was probably from a crocodile. Small pellets in a heap were male impala marking territory, as well as providing nitrogen and phosphorus for plants. Female impala scat were a more scattered whisper across the landscape, and less a megaphone to announce ownership. Buffalo dung pies were flat, circular pats like domesticated cow dung, but firmer. Zebra feces, as we might have expected, were more horse-like, kidney-shaped, and darker than buffalo dung. Hippo dung on the path was like that of an elephant — a big cylindrical sausage — but wetter and with less fiber. The increased water content is associated with a lower concentration of nutrients, meaning it is less attractive as a food source for other species than elephant dung. The lower fiber concentration also means hippo dung is less useful for making paper than elephant dung. Hippos, who cannot see well, use a tactic that would have saved Hansel and Gretel, with their dainty bread crumbs, considerable grief. They mark the path to and from the river with their dung when they go on nighttime food foraging and pillaging expeditions, so they can use it to find their way back from the riverbank. Hippos are thus moving nutrients from the water to the land and, when they defecate in the water (which they also do), back to aquatic systems.

Each of the scats I saw along the trail in Tanzania told me something about the animals and their ecological places in this landscape, and the ways in which they have physically changed the landscape (eating plants, stomping paths, transferring seeds). Nevertheless, looking at animal scat was still vaguely unsatisfying. What I really wanted to see, much to the dismay of my fellow safari-ists, most of whom were honeymooners, were the queens of the wilderness — dung beetles. I think I was, at first, somewhat amused by the notion that there are animals that literally eat shit. What did they look like? How did they do it?

I was heading back to my tent after the walk when Eduard, one of our two guides, came running after me. He and Mpato had found some dung beetles near the camp, hard at work! Strangely, as Eduard told me about this amazing find, the other tourists disappeared.

“You go,” said my wife. “I have some important reading to do.”

“Their loss,” I thought as I followed Eduard a hundred meters down the path to where Mpato was guarding a large pile of elephant dung with his hunting rifle. I crouched next to him, the sun beating down on my head, the sweat trickling down the middle of my back.

If I was disappointed with what I saw, I did not show it, although I had secretly wished for a re-creation of the scene described by two researchers in 1974; they had observed 16,000 dung beetles attack one 1.5-kilogram pile of elephant dung and eat, bury, and roll away the whole pile within two hours. I had to remind myself that seeing even two thumb-sized black beetles scuttling around the dung-pile was more than I should have expected this time of year. In the dry season, most dung beetles in the area were already hunkered underground in front of their television sets, watching reruns of Bushland Idle.

One of the two beetles was industriously pulling down chunks from the heap of dung and tamping them down to form a ball. Nearby, another beetle was busy burying his ball. The sandy earth shifted up and down with his subterranean digging movements. We squatted in the hot sun, watching the manic, obsessive beetles at work. If Mpato and Eduard were puzzled at my interest, they were too polite to show it.

Just when we thought he seemed done, when the walnut-sized sphere of dung — twice his size — looked perfect to me, the beetle would pull down another piece and tap it into some imperceptible imperfection. Finally he started rolling the ball away from the dung pile, uphill, over twigs, his hind end up against the ball, front end down on the ground. He strained and tumbled over a small branch and rolled into a little gully, still clinging to his large ball. Then he clambered up, had a look around at the lay of the land, and started pushing again. Periodically, he dug down into the earth or under the leaf litter, then came back up and resumed pushing. He pushed and tumbled his way some eight meters from the dung pile, uphill almost all the way, until he finally started digging seriously, his ball sinking into the leaf litter, heaving once or twice, and then sinking from view.

The other beetle, nearest to the dung pile, made another, smaller, ball, dug a hole, pushed in the ball, and then came back out and pulled in more dung. Both beetles were probably males, who are stronger than females, and who usually do the rolling. Sometimes, males and females will roll the ball together, bury it, dig a tunnel nearby, have sex, and then insert the fertilized eggs into the ball. If another male comes along that wants sex with the female, the two males lock horns and try to push each other out of the tunnel. According to some researchers, these battles for sex have resulted in some beetles that can pull more than 1,000 times their own weight — a person, say, pulling six double-decker buses full of people. It would not be the first time that a male has gone to the gym to improve his chances of finding a sexual partner.

In the case of the beetles I was watching, I could see no females around. Perhaps they had already bred. Or perhaps they were single males, unlucky in love, tucking away a bit of nourishment for the rest of the dry season, in which case there was some poignancy to the scene I was observing.

Whatever their personal stories, it occurred to me that what I was watching was surely more than a curiosity. A huge amount of energy was being expended by these animals to build and bury these large nutri-balls of manure. While this energy use makes sense for them as individuals in that it enables the survival of their young, it also makes sense in much larger terms. For what nourishes their young also nourishes the landscape, which provides food for the elephants, who provide the shit that allow the dung beetle babies — as well as many other species — to live through the dry season. A 2008 review of the ecological literature on dung beetles by the Dung Beetle Ecology Working Group of ScarabNet summarized contributions of various dung beetles to cycling of nutrients, enhancing plant growth, controlling parasites, and dispersing seeds. The unpaid and unsung work of these beetles in parasite control, pasture improvement, and reduction in greenhouse gases has contributed hundreds of millions of dollars to global agriculture.

There are dung beetles on every continent except Antarctica. Many are adapted to work not just in particular landscapes, but are also fastidious about the kinds of dung they eat. The dung beetles of Australia, for instance, accustomed to marsupial dung, wanted nothing to do with cow pats. For almost 200 years after European settlement, as the geographic extent and number of cattle increased, the problems associated with dung flies and general stinky unpleasantness increased. In the 1970s, in an experiment considerably more successful than the ill-advised importation of cane toads to kill cane pests, some twenty species of African dung beetle were selected and imported. These brought the cattle manure situation under control and helped improve soil and pasture quality. Unfortunately, the widespread use of drugs to treat insect pests on cattle, a process which also kills dung beetles, may now be reversing some of those gains.

Like all of us, dung beetles can be classified by their physical characteristics, their genetics, and their behavior. The ones I observed in Tanzania were rollers: they wrap a ball of feces around their eggs and then bury them. When the larvae hatch, they eat the dung around them, which must mean that the dung itself is rich in energy and nutrients — energy and nutrients that would otherwise leak away into the environment. Not all dung balls are as small and malleable as the ones I saw. The balls created by some Indian scarabs have been mistaken for old stone cannonballs, because the clay with which the beetles covered them had hardened. Tunnelers bury the feces, and dwellers, the laziest of the bunch, just live in it. Some species hang around watching a neighbor roll up a large ball, and then, when he skitters off to get more dung, they steal it!

While there are ongoing debates among coleopterists (people who study beetles and their habits) over details of beetle evolution, what is not in doubt is that excrement-eating beetles have been around for a long, long time. Early scarab beetles (Scarabaeoidea), from which modern dung beetles evolved, appear to have been around for more than 150 million years, and “true” dung beetles (the ones that actually eat dung), about 40 million years. Evidence from fossilized dung pieces, called coprolites, suggests that dung beetles developed commensal relationships with dinosaurs in the Mesozoic period, that is, more than 65 million years ago, when the continents were slowly creaking and groaning on their rebellious, separate ways, budding off from mother-father Pangaea and carrying with them a variety of species to start new lives elsewhere on the globe. If we are serious about staying around on the planet for a long time and maintaining a meaningful, if challenging, lifestyle, we could do worse than to consult the dung beetles.

Many scientists love to get close, really close, to nature, to focus on a few small things to the exclusion of all else. So, if you search the literature on dung beetles, you will find references to anywhere from 5,000 to more than 7,000 species, divided into twelve tribes, with a couple hundred new species being described every year. There are about 100 species of dung beetle devoted to elephant dung alone. Part of the problem of keeping count is that the nomenclature has been unclear, with some writers slipping back and forth between “dung beetles” and “scarabs.”

Although all scarabs are great recyclers, not all scarabs are dung beetles. The Scarabaeoidea are a superfamily, including within it families whose names include such luminaries as sand-loving, enigmatic, earth-boring, rain, and bumblebee beetles. They include fungivores (which eat fungi), herbivores (eat plants), necrophages (eat dead things), carnivores (eat other animals), saprophages (eat any kind of decaying organic matter), and — the ones that interest us in this book — the coprophages (eat shit). Species in the subfamily Scarabaeinae are sometimes referred to as the “true” dung beetles, since most of them feed almost exclusively on feces. The taxonomic boundaries of their families, subfamilies, and tribes may be unclear, but all can claim royal heritage. Scarabs were revered, and rightly so, by the ancient Egyptians — another case, and there are many, where traditional religious practices helped preserve important ecological functions.

To the ancient Egyptians, rather than representing filth and feces, the scarab suggested death and rebirth, renewal and resurrection. Like the god Khepri, who created himself from nothing, rolled the sun through the darkness, and, voilà, presented it new each morning, the scarab rolled its sphere to the underworld and, fifteen to eighteen weeks later, was reborn. Hence, the name and picture used to depict the scarab was “to come into existence,” and hence the celebration of the scarab in precious metals and stones, bones and ivory, in funeral rites of the region and in “mummy” adventure B-movies.

While most tourists in Africa pay attention to the so-called charismatic megafauna such as impala and elephants, few are attentive to the much smaller creatures that help create the landscapes in which those larger animals live, and which enable them to survive. Early in human evolution, it made sense to pay attention to animals you could eat, or that might be a threat to you. In the twenty-first century, it is the loss of the animals we don’t see, and for which we don’t see an immediate use — dung beetles for instance — that may pose the biggest threat to us. Dung beetle safaris should be the next great opportunity for ecotourism.

As I watched the two East African beetles at work, I reflected that these animals were more than a curiosity. They embodied, in many ways, a question that had been eating away inside me, like dung beetle larvae in a dung ball, over decades of teaching epidemiology of foodborne and waterborne diseases. How and why has excrement — which is absolutely necessary for the resilient functioning of our planet, and which has, in fact, been a solution to a myriad of biological problems thrown up by the long haul of evolution — become, in the past mere few thousands of years, a problem to be solved? When was the challenge of dancing through this amazing web of life-giving-life reduced to an issue of sustainable manure management?

Every day, all around the world, by eating or burying what others consider waste, dung beetles turn water into wine, contaminated refuse into livable landscapes. They are the Rumpelstiltskins of the animal world, weaving gold from dung-straw. They close the feedback loops of nutrients and energy that are essential for the resilience and health of the ecosystems that are our home. Can we learn from them? Is it important that we learn from them? Should we give, as they say, a shit?

Over the past few years, variations of this story circulated on the internet:

A man in a dark blue suit makes his way down the aisle of the airplane and is delighted to find that there is a pretty woman in the seat next to his. He takes off his suit jacket, carefully folds it, and places it in the overhead bin. Then he sits down, loosens his tie, puts his computer under the seat in front of him, and looks over at her. She is reading a book and does not look up. He clears his throat. “I always find that the flight goes faster if you strike up a conversation with your fellow passengers.”

The woman slowly closes her book, brushes her dark, wavy hair away from her eyes, and asks, “Okay, what would you like to discuss?”

The guy says, “Oh, I don’t know. Anything. How about nuclear power?”

The woman sighs. “That could make for a pretty interesting conversation. But let me ask you a question first, okay?”

“Sure,” he says. “Why not?”

“A horse, a cow, and a sheep all eat grass, but the sheep excretes pellets, the cow plops out patties, and the horse puts out something that looks like rye buns. Why is that?”

The guy shrugs his shoulders and grins at her. “I don’t know.”

She stares at him. “So, do you really think you’re qualified to discuss nuclear power when you don’t know shit?”

She opens her book and resumes reading as the plane takes off.

It is always risky to deconstruct a joke, and even more risky if the joke involves some slightly impolite topic. But I will do so, because the story I am about to tell in this book is woven around the pun in the airplane joke. The unhappy male traveler is caught in the snare of not knowing much about excrement and is therefore accused of not knowing much about anything. In fact, the woman’s use of the “s” word is a triple threat. She is not only being sarcastic about his knowledge of biology, and his lack of knowledge about life in general, but she is using a word that is generally reserved for the drunken carelessness of bars or hormone-driven bravado of locker rooms. Hence she is at once implying that the topic is profoundly important and maligning it. As a beautiful young woman well versed in the techniques of deflecting unwanted male interest, she can get away with this contradictory put-down, to which there can be no winning response.

I empathize with the man, in no small part because he is a man on an airplane trying to make diverting conversation, which is a situation in which I have often found myself. I also empathize with the hapless fellow because, as a veterinarian, I have found myself on occasion with my arm up a cow’s butt, or examining feces from a dog, or lying in a gutter full of animal excrement, or even, more recently, seriously studying all manner of human and animal diseases transmitted by what is called the fecal-oral route (which you won’t find on Google Maps or MapQuest). Nevertheless, I realized, somewhat late in my professional life, that I actually knew very little about the stuff.

Staring at those dung beetles, a mad white man under the blazing midday sun, I realized that before we can understand why they are so important, not just in themselves, but as an exemplar of the kinds of solutions we might devise to face the complex challenges of surviving through the twenty-first century, we must understand the larger context, the universe in which we are all indigenous peoples.

Through decades of work on human foodborne and waterborne diseases, I have discovered that excrement, and how we think about it, is profoundly linked to everything I care deeply about — culture, food, health, ecological sustainability. Especially ecological sustainability, without which nothing else exists. The lovely young lady on the plane is absolutely right. Really, if you don’t know road apples from cow pies, shit from fertilizer, you probably shouldn’t be talking about nuclear power; the fact that most people in the power business (political, economic, energy) cannot speak intelligently on the subject indicates a profound ignorance, rooted in a deep alienation from our most essential biological selves.

The way we treat excrement is a choice that feeds certain species and steals from others, destroys certain ecosystems and builds up others. Why has shit become such a public health and environmental problem, when it would seem to be such a smorgasbord of ecological opportunities? Unless we change how we think about shit, we are doomed to forever live in it. Or perhaps, more accurately, we already do live in it, and always will, and unless we change how we think about it, we will continue to create very unfortunate problems for ourselves.

This book is about rectifying (no pun intended) our ignorance, and achieving that wisdom of discernment. But more than that, this book is about moving through discernment to the unified reality that underlies everything, the nameless ground of all being, to what the ancient Chinese called the Tao and the tribes of the Middle East, the “I Am.” If this seems to you too ambitious a task for a small book about feces, if this seems too large a burden to place on such a small beast as a dung beetle, then, dear reader, you are exactly the person for whom this book is written.

Despite our journey from the inchoate soups of the early universe to the highest achievements of modern civilization, we are still, deep inside, animals. Whatever our station in life, rich or poor, powerful or downtrodden, priest or anarchist, man-god or ape-man, we still have to urge the passage of materials through our bowels. If we can understand this substance that emerges from us, from all animals, as an ecological unifying principle, which goes back to our evolutionary origins and the roots of our belonging, then we can, with serenity and happiness, deal with all the visible shit that surrounds us.

Read on. Know shit.