Go Wild With Annette: The Unsung Dung Hero
Introducing ecosystem engineers with a difference
By Annette J Beveridge
Piles of poop may not be fascinating for many but these beetle poop scoopers provide a vital service.
I am talking about our very own dung beetles.
Picture the scene. Farm animals, deer or rabbits leave dung as they roam. Whenever excrement occurs, know that there will be a whole community rushing to the scene, carrying dung away, breaking the dung down, and taking away nutrients. Dung beetles are keystone species because they help to disperse seeds, clean up and recycle nutrients.
There are approximately 6,000 species of dung beetles across the world and the ones that spring to mind are the African beetles recorded on wildlife documentaries.
In Britain, we have 60 species of dung beetle, many of which belong to the Scarabaeidae family. However, there are the earth borers, (Geotrupidae) which includes the minotaur beetle.
This beetle is most commonly seen in autumn as it is when the adults emerge. This is the only ‘dung-roller’ in the UK.
The minotaur beetle (Typhaeus typhoeus) is a large, glossy black beetle. It is named for the male’s distinctive three horns. Females do not have the horns but on the plate-like structure that covers the thorax, there are visible pointed edges on the front corners.
The beetles are often just over an inch in length and they bore deep into the earth beneath piles of dung creating burrows for both breeding and feeding.
Mating
Food is important for dung beetles and they will eat as much as they can prior to mating.
When trying to find a mate, the beetles take to the air. Males will fight for a female and will clash, locking their horns together in the effort to be the victor.
Once mating takes place, the pair will find a spot close to rabbit latrines and will dig into the soil creating a tunnel which can extend for a metre and a half.
Minotaur beetles drag the dung pellets - from deer, sheep or rabbits moving backwards and holding the pellets with their front legs. Males work hard on the surface mostly collecting dung and inserting it into the burrow. The female shapes the dung and takes it into the chambers prepared for her brood.
On mild winter days, the female lays an egg in each chamber - up to 12 eggs usually. As soon as eggs hatch, the larvae start to eat the dung in its chamber.
During this time the male guards the burrow.
Adult minotaur beetles die in the spring or summer once the brood is established. The larvae pupate and the whole cycle of life continues once they emerge in the autumn.
Ecosystem engineers
These beetles are important. They are ecosystem engineers. Because they burrow into the soil, they help to aerate and fertilise it. Minotaur beetles may also reduce parasites in livestock and reduce methane from releasing into the atmosphere.
But the mighty minotaur beetle is not without predators. Bats, hedgehogs, owls, and starlings will feast on them.
Where to find them
Dung beetles are declining in the UK due to a loss of habitat, field ploughing, and the use of wormers for farm animals. This treatment can kill dung beetles.
Minotaur beetles can be found in England and Wales - but less so in the north of England. The beetles are very rare in Scotland.
If you want to see minotaur beetles, find a field with suitable amounts of dung and shine a torch as the beetles are attracted to light.