By: Priscilla Hayes
My friend, Penny Jones, has long been a dung beetle fanatic, so much so, that her husband presented her with a mounted dung beetle in a frame. She even has her own pair of dung earrings! As a recycling professional, she particularly appreciates that dung beetles are the ultimate recyclers, fashioning dung—not even a waste they are responsible for producing—into balls bigger than they are, and then rolling the balls off for their own use. In contrast, we humans are notoriously poor at recycling our own waste, let alone that of some other organism or planetary force. It is clear we could take a lesson from these creatures.
Unlike Penny, I still had a rather rudimentary knowledge of dung beetle activities, when I got a seminar announcement via email, as I sat at my desk at Rutgers University. I invited Penny down to the dung beetle seminar, which was to be given by a National Geographic researcher, Dr. Kevina Vulinec. Once Penny had indicated she and her husband would attend, I realized I would, of course, need to join her.
Dr. Vulinec had been studying the interactions of monkeys, dung beetles and trees in various rain forests across the world, to see if there was proof of co-evolution. I know she described observations of various kinds of monkeys in various different rain settings, but the ones that took my fancy were the howler monkeys.
Howler monkeys are apparently more social than some other monkeys, and more prone to group activities. These monkeys get up in the morning, and gather on a branch to eat fruit—whole, with the seeds inside—and then have a “group poop.” The poop, naturally enough, falls down from the tree into a pile on the ground below, where dung beetles form balls of poop, then roll them away to bury and inject eggs into. By doing so, each beetle assures its hatchlings a ready supply of food, before they must venture out to find their own food (poop) and risk being eaten.
But, remember that the howler monkeys ate the fruit whole! So, when the dung beetles roll away with poop, they also carry the tree’s embryos, its seeds. The tree gets its seeds planted in a location where the offspring won’t directly compete with the parent tree, and the baby trees, as with the baby beetles, have a ready supply of food for their initial development.
Here I must confess that, although I don’t have dung earrings like Penny’s, the seminar started my own love affair with dung beetles. For a while I collected stories: someone had brought a dung beetle home from Florida, and fed it baby poop (it didn’t last too long). Our department chair had observed the extreme level of care—complete with forced detours—taken in Africa to make sure that trucks didn’t drive over the beetles that are so essential to cleaning up cow manure there. My student interns collected dung beetle photos and humor for me. Perhaps the most fun fact I learned was from one of my favorite books, Dirt, the Ecstatic Skin of the Earth by William Bryant Logan, which has an entire chapter on dung beetles. There I learned that dung beetles actually fly up to the branches where the monkeys are busily eating fruit, and hang out waiting to attach to a piece of dung as it leaves a monkey’s butt and begins to descend to the forest floor. Dung is in too hot demand there to take chances that it won’t be scooped up by some other beetle or other organism from the ground. So, the beetles actually takes their lives in their own wings (since there is not only a hot demand for the poop, but for the beetles, which many animals find to be a tasty treat) to gather poop on the fly.
Dung beetles have become a go to lesson for many presentations I do, since they so clearly typify symbiosis, benefitting all the organisms along the chain. They present such a clear challenge and inspiration for us humans to make sure that we at least cycle the natural resources that are the stuff of our everyday life.