Bull headed dung beetle (Onthophagus taurus), courtesy Baylor College of Medicine

One of the most powerful tools a rancher has to improve pastures is this little creature called a dung beetle. They are magnificent creatures that are increasingly being eliminated by chemicals used to treat cattle in the United States. I’ve been studying these beauties all summer and want to share a few facts about them and discuss the promise they have to combat global warming and be the answer to navigation. Additionally a healthy population of dung beetles sequester carbon in soil, the degree of this is unknown but may have huge benefits that we dont fully yet understand.

So contrary to the current debate on methane emitted from cows the dung beetle actually captures part of the carbon emitted in the first place. In other words in a healthy pasture or range that is populated with dung beetles the reported carbon emmission numbers ( 22.3 kg of carbon dioxide-equivalent GHG emissions per kilogram of beef) would be inaccurate as it does not measure a net number based on forgage systems that include dung beetles.

The basics to how this works are a dung beetle flies around pastures at night and digs into fresh manure piles. Their are different types of beetles, burrowers who as you can imagine dig into the excrement (cow patty) and then tunnel beneath it up to a foot or more deep depositing eggs. The tunnels ( think nurseries) are filled with excrement which is partially eaten as the new hatched larvae soon to become beetles come out. Once hatched and they fly away leaving behind small holes punched into the topsoil lined with manure that fill with water when it rains. The effect this can have on a pasture over time is profound. This is apart from the fact they eat fly larvae reducing fly and parasite populations. Below is a diagram I created to illustrate the process.

Life cycle of a dung beetle and how they increase my pasture's ability to hold moisture

Even stranger I learned is dung beetles have a biologically unique navigation system. These beetles are primarily nocturnal , I've observed some flying at dusk and they have an exceptionally keen sense of smell. Their brains use light to navigate as illustrated below.

Neuroanatomy of dung beetle brain

These beetles use a combination of polarized light and celestial navigation to know exactly where they are. When doing this they track the moon over its lunar cycle and use it for night-time navigation (which is when they are most active). A lot of homing insects, like bees and ants, it is believed employ a long-term memory of visual landmarks to find their way home, but dung beetles are radically different and use stars and the lunar position for a type of celestial navigation that is complex and not understood. Ironically the ancient Egyptians thought these insects (known to them as scarabs) were gods. These are the only known biological entity other than humans that use stars to navigate. This god analogy - and I belive that is exactly what it was due to the knowledge they have is far more powerful and accurate than the GPS system we currently use diagrammed below.

Forest

I am hopeful with advances in a.i. and minaturization of technology we can study and learn to fully understand how this system works as it could be of great value to how humans ultimately navigate space. The knowledge to identify one’s location from the light transmitted by stars would be a remarkable achievement. I believe in time we will be able to develop a system of navigation based on how these beetle navigate according to an analysis of light. Contrast that to the incredibly complex technology and infrastructure we now use to navigate - a system of satellites (currently 32 ) requiring line-of-sight with expensive optics and a hand-held recievers depending on at least the ability to connect to four satellites orbiting overhead. A dung beetle has sub-centimeter accuracy with the biological surface area smaller than a pin tip.

Measurements of the active neural area of a dung beetle brain used for navigation as compared to other insects
All the holes are where dung beetles burrowed in
36 hours elapsed
48 and 72 hours elapsed

Earlier this summer I went to central Florida to visit Sandra Marvel at Marvel Farms - she and her husband have brangus cattle operation and I purchased a hundred beetles to re-establish them in my pastures in south Alabama. I've learned several things kill beetles. Most common is how we treat cattle, a commonly used medicine Ivomectin for example can eliminate beetle populations for years as can roadside right-of-way herbicides. There are options as to how this can be avoided which I will document this spring.

If you have made it this far you can see this is a favorite topic of mine that I feel provides us the opportuniy to learn so much more about ecology and livestock. This is a subject I will come back to many times. One thing I want to do is try to develop a way photograph the beetles flying at night and get airborne counts. Let me think through this and what I need. Dung beetles people, they are fascinating and valuable to our landscapes value them!

These are the different types I've been able to identify so far