Courtesy Whitney Cranshaw/ Colorado State University Dung beetles are funny creatures to watch. Here, the larger female beetle pushes the dung ball while the male rides it. |
The other day, Uzzi and I were lying in the shade chewing cud when we glanced down and our eyes bugged out—there was a shiny black beetle pushing a big ball of manure with his back feet. We got up and followed him, and he went straight as an arrow across our paddock. Twice he stopped, climbed up on his manure ball and danced a jig!
That night we crept into the house, booted up the computer and surfed to an insect identification site. The strange bug was a dung beetle, the roller kind. And we discovered that dung beetles are cool!
There are more than 5,000 kinds of dung beetles in the world and each falls into one of three types: rollers (some people call them tumble bugs), tunnelers and dwellers. Rollers roll manure (that’s dung, in case you don’t know) into round balls and push them. (They can push up to 10 times their weight.) They use their manure balls as food storage or brooding chambers. Tunnelers bury manure wherever they find it, and dwellers simply live in manure.
All dung beetles eat manure, and that makes them important in our ecosystem. By burying manure, dung beetles loosen and improve soil structure while clearing an area of excess dung. Did you know that a single cowpat can generate 60 to 80 adult horn flies if protected from competitors, like dung beetles? However, as dung beetles feed, they compete with horn-fly larvae for food and physically damage the horn flies’ eggs. Our friends Aiah and Ludo make lots of cow flop, and horn flies bite! Good thing we have dung beetles on our farm.
There are big and little dung beetles, ranging in size from 1/5 to 2½ inches long. They can be black, brown or reddish, usually with a cool metallic sheen. Their front legs have serrated edges used for digging, and males of some species have horns. They’re drawn to manure by odor. Once they find manure they like, they dine on its liquid contents. Dr. Patricia Richardson at the University of Texas calls this a “dung slurpie”.
W. Wyatt Hoback and Sean D. Whipple of University of Nebraska spent two years capturing more than 9,000 dung beetles of 15 species in pitfall traps baited with native and exotic manure to discover what kind they like best. They found that dung beetles prefer manure from omnivores—species that eat both meat and plants—and that their favorites are human and chimpanzee manure.
A lot of people are passionate about dung beetles, like Emily Baird, of Lund University in Sweden, who studies dung beetles to figure out why rollers stop and dance on their dung balls from time to time. She thinks it’s to get their bearings. She came to this conclusion after placing tiny hats on dung beetles to block their view of the sky. The hat-wearing beetles became disoriented and couldn’t push their dung balls in straight lines.
Uzzi and I looked at each other when we read that. Dung beetles wearing tiny hats! Next time we’ll look closer when a dung beetle rolls by. We don’t think our beetle was wearing one.
