Brian Magnier | Dreamstime.com
WILD THING
Dirty Job
Dung beetles roll away all that animal ... stuff.
We don’t like to talk about what happens to our waste. Whether household garbage, sewer content or old vehicles, waste is removed from our thoughts as soon as it’s out of our sight.
As we search for better ways to recycle, we’re reminded that nature has been helping us repurpose our waste (and that of other animals) for thousands of years.
Some beetles fill a nasty niche of processing animal waste, our dung. Without creatures like dung beetles and flies (and even bacteria), we would be surrounded by it.
Dung beetles utilize excrement as a part of their life cycle and make those nutrients available to plants and other organisms. Bison and other grazers once roamed the prairies and savannas of Texas, foraging on grasses, but how were the nutrients from the waste they left behind reintroduced back to the vegetation?
Quite a few nutrients remain in animal dung, due to digestive inefficiencies. Creatures like dung beetles utilize and process that material to provide nourishment to their growing young. Dung beetles will lay their eggs in this nutrient-rich excrement; their larvae will feed on it until they emerge as full-grown adult beetles.
Believe it or not, there can be a lot of competition for dung, and these beetles have adapted behaviors to keep some for themselves.
Meet the rollers, tunnelers and dwellers.
• Rollers move it away from the pile and others who might steal it. They are entertaining to watch and have a very good sense of direction, despite their aimless behavior.
• Tunnelers move dung underground directly below where it was deposited. Flip some dung over and see if there are small holes in the ground. That’s tunneling.
• Dwellers live and reproduce in the dung itself. They’re often quite small but visible if you break open the dung.
In addition to being productive nutrient recyclers, these beetles can also be quite beautiful. The most charismatic of our Texas species is the rainbow scarab, multicolored and sculptured. The males also possess a very distinctive horn.
Texas has 58 dung beetle species and hundreds more beetle species that utilize dung. All have close relationships with many species of mammals and sometimes birds. Keep your eyes open when you are outside — you may be lucky enough to see these beneficial insects doing a job that many of us wouldn’t touch.
courtesy Denver Museum of Nature & Science
Phanaeus difformis
courtesy Denver Museum of Nature & Science
Corpus frictator
courtesy Denver Museum of Nature & Science
Phanaeus vindex
courtesy Denver Museum of Nature & Science
Onthophagus hecate
courtesy Denver Museum of Nature & Science
Onthophagus orpheus pseudopheus