American Burying Beetle
(Nicrophorus americanus)
The American burying beetle is but one of the millions of insects and other invertebrates that play such a major, though seldom acknowledged, role in the maintenance of habitats and ecosystems. Most people simply lump them all into the category “creepy-crawlies” or “bugs.” Some, such as butterflies, are admired and loved for their beauty (though people tend to be less interested in or even repelled by their caterpillars). Others, such as spiders, are the inadvertent cause of fear—even terror. Cockroaches are loathed. Hundreds of species are persecuted for the role they play in damaging our food—such as the desert locust, which ravages crops across huge areas. And there are countless species such as mosquitoes, tsetse flies, fleas, and ticks that carry diseases that can devastate other creatures, including ourselves.
It is for these reasons that they have been attacked by farmers, gardeners, and governments. Unfortunately the weapons of choice have been chemical pesticides—and this has led to horrific damage of all too many ecosystems, either through directly killing countless life-forms in addition to the intended targets, or when poisoned insects are eaten by creatures higher up the food chain.
Yet for every species that harms us or our food, there are countless others that work away, sometimes unseen, for the good of the environment where they live. I first became aware of this when I was a small child, picking up every earthworm I found stranded on the road (as did Dr. Albert Schweitzer, by the way), and then learning about the valuable contribution they make to soil health. Millions of invertebrates provide food for species—including our own—higher up the food chain. In many places people feast on termites, locusts, and beetle larvae—even I have tasted these things! Bees pollinate the vast majority of our food crops, and the current devastation of hives in North America and Europe is causing real anxiety.
Lou Perrotti, coordinator for the American burying beetle for the Association of Zoos and Aquariums, is a passionate advocate for these beetles. Here he is checking a brood on Nantucket Island, Massachusetts. “Somebody needs to be out there saving these critters,” he told me (note the tattoo on his forearm). (Roger Williams Park Zoo)
And what about the American burying beetle? What role, if any, does it play in our environment? This is what I learned about when, on March 18, 2007, I met with Lou Perrotti and Jack Mulvena of the Roger Williams Park Zoo in Providence, Rhode Island. Back in 1989, they told me, biologists had realized that the American burying beetle was fast declining, and it became one of just a few insect species to be listed under the Endangered Species Act. Then in 1993, the Roger Williams Park Zoo started a breeding program for the US Fish and Wildlife Service; in 2006, this beetle became the first insect species to be assigned a Species Survival Plan. Lou is currently the coordinator for the American burying beetle for the Association of Zoos and Aquariums.
As he began talking about the beetles, it was immediately apparent that they had the perfect spokesman! He is a man passionately interested in insects and, he told me, has “loved all things creepy-crawly” since he was a child. Like so many of the other people I have talked to while gathering information for this book, Lou had parents who were understanding and supportive of his fascination with invertebrates. (And other creatures, too—they allowed him to breed boa constrictors when he was nine years old!)
While we talked, Lou became increasingly animated. “Somebody needs to be out there saving these critters [the burying beetles],” he said. And that is just what he is doing. Let me share some of what I learned from him about these remarkable beetles. Most people have no idea how fascinating they are. Certainly I hadn’t.
The American burying beetle is the largest member of its genus in North America—it is sometimes called the “giant carrion beetle.” Once these beetles lived in forest and scrub grassland habitats—anyplace where there was carrion of a suitable size and soil suitable for burying it—in thirty-five states throughout temperate eastern North America. But by 1920, populations in the East had largely disappeared. By 1970 populations had also disappeared from Ontario, Kentucky, Ohio, and Missouri. And during the 1980s, the beetle declined rapidly throughout the American Midwest.
Today there are only seven places where they are known to exist—Block Island (Rhode Island), a single county in eastern Oklahoma, scattered populations in Arkansas, Nebraska, South Dakota, Kansas, and a recently discovered population on a military installation in Texas. One reason for the species’ precipitous decline across its historical range, in addition to habitat loss and fragmentation, is possibly connected with the extinction of the passenger pigeon and the greatly reduced number of black-footed ferrets and prairie chickens, all of which provided carrion of ideal size.
Why We Need the Burying Beetle
Let me return to the question I asked earlier—would the loss of the American burying beetle matter? The answer, stressed by Lou and Jack, is an emphatic yes. They feed on carrion—the flesh of dead animals. Lou calls them “nature’s most efficient recyclers” because they are responsible for recycling decaying animals back into the ecosystem. This returns nutrients to the earth, which stimulates the growth of plants. And by burying carcasses underground, this industrious beetle helps keep flies and ants from reaching epidemic proportions.
Lou explained how these beetles find their meals. They can “smell” carrion from as far away as two miles, by means of sensors on their antennae. Flying noisily through the dusk, a male usually reaches the carcass he has located soon after dark. Then he—and any other males who have also discovered the feast—emits pheromones that are irresistible to females of the species. Thus, you’ll likely find a number of beetles gathered around any one corpse. It seems they form pairs, and there may be a good deal of fighting until one couple claims the prize. They then cooperate to bury it. This can be hard work: A carcass the size of a blue jay will take about twelve hours to bury.
Beetle Co-Parenting
Once the carcass is safely underground, the beetles strip it of feathers or hair and then coat it with anal and oral secretions, which help to preserve the flesh that will serve as food for their young. Next, the couple consummates their pairing, and within a day the female lays the fertilized eggs in a small chamber that they have dug out close to the carcass. Here both parents wait for their eggs to hatch, which will be in two or three days. Both mother and father carry the larvae to their “larder.” And then—and this really blew my mind away—the young beetles will stroke the mandibles of their parents to entice feeding, and the adults will regurgitate food for their young. How absolutely amazing—an insect species in which mother and father care for their young together!
Usually, by the time the carcass is safely underground, flies have already laid their eggs on it. These hatch quickly into hungry competitors for the young beetles. But help is close by: Riding on the bodies of the adult beetles are tiny orange mites that quickly climb onto the carcass, where they feed on fly eggs and maggots. In about two weeks, the sated beetle larvae burrow into the soil to pupate, and the parents move on. As they do so, the orange mites hop back on board. The young beetles will emerge about forty-five days later.
Lou and his team have been very successful with their captive breeding program—by the end of 2006, more than three thousand beetles had been reared and released into the wild on Nantucket Island. The captive-bred females (each paired with a genetically suitable mate) are transported to the release site in plastic containers. These are placed in an Igloo cooler, since the beetles cannot survive undue heat. A second cooler is used to transport dead quail, which the beetles will use as the carrion for their young. With a chuckle, Lou told us, “I can be traveling on a ferry during the height of tourist season and will still have room around me due to the terrible smell coming from the coolers.”
At the release site, holes have been pre-dug for the beetles. The dead quail are placed into the holes with floss tied to their feet and attached to a small orange flag to assist the recovery team with finding the buried carcasses at a later date. The beetles are then released into the hole, where ideally they will realize that they have a jump start on the reproduction process! Lou said that Nantucket was chosen as a release site because, as with Block Island, there are no mammalian competitors present. After a while, though, birds such as crows and seagulls began to recognize that an orange flag represented a food source, and began to dig up the beetles’ carrion, so the recovery team is now also placing a mesh screen over each brood to protect it.
Lou told me that he really enjoys teaching children about insects. We agreed that it does not take much to trigger their interest—children are naturally curious. And “creepy-crawlies,” although they may elicit fear and horror, hold a real fascination for them. I told Lou I had spent hours as a child watching spiders, dragonflies, bumblebees, and the like. My son was fascinated as a little boy to watch ants as they set out in an orderly column to raid a termite nest, and returned each bearing an unfortunate victim in its mandibles. And my sister’s three-year-old grandson, after watching a snail crawling over the ground, suddenly placed it on the windowpane and rushed indoors to look through the glass, clearly fascinated and curious about the mechanism that enabled the creature to glide forward, as if by magic.
Unfortunately, Lou finds it much harder to interest adults in the efforts being made to save the American burying beetle. “So often the first question,” he told me, “is ‘Will it eat my garden?’” If only people would take the time to listen, retain the curiosity and wonder of childhood, how much richer their lives would be. Certainly during my short early-morning meeting with Lou and Jack, I had been transported to a different and utterly fascinating world, where giant insects nurture their young and tiny mites, in exchange for a free meal and a ride to the restaurant, rid their benefactors of their competitors.
After our visit, Lou sent me a beautiful print of an American burying beetle, its orange and black colors vivid and glowing. It is propped against the wall as I write, reminding me of all the magic of the natural world.