promoting soil heath and biodiversity
Our British dung beetles are perhaps the unsung heroes of the suite of ecosystem engineers we enjoy having alongside us in our landscape. They are under-researched, despite the wealth of positive impacts they have on our rural areas, and wider environment.
I attended a webinar hosted by Harriet Trueman of the Wilder Ouse project with Sussex Wildlife Trust all about these fascinating insects. I love big beetles, and was interested to hear about the benefits, and the challenges faced by the different types, as most of the 60 species we have in the UK are in decline.
Our native dung beetles have two “lifestyles” – some live in the dung itself; others live in tunnels beneath. We don’t have any of the dung-roller species seen in memes and on Planet Earth which are perhaps more familiar, although the larger beetles have been observed rolling rabbit dung, but that is spherical already so probably more luck than judgement. The tunnellers can dig channels over a metre deep in which to house their offspring accompanied by a tiny foodball of dung, the consequence of which is to both aerate and bring nutrients down into the soil. The dwellers create holes and dry out the dung, and provide food for birds. Corvids love the beetle grubs, and will spread the dried dung around as they forage, thus further distributing the nutrients over wide area.
Dung beetles will utilise dung from all grazing animals as well as carnivores, although they are most beneficial in an agricultural environment where a build up of dung can result in a pasture becoming sour. The beetles’ activity can also reduce fly and parasitic worm burdens by drying out the dung making conditions less favourable, encouraging birds in to feed, and eating the eggs of flies and worms themselves. Sadly intensive agriculture can compromise the very actions they are trying to promote with the use of anthelmintics: it’s been found that 90% of worming preparations are present in the dung, and these negatively affect the dung beetles, meaning they can’t do their good work. Other common practices, such as removing manure from horse paddocks, take away the food for the dung beetles. Of course, animal welfare is key, but actually encouraging a healthy population of dung beetles can dramatically scale down the need for manure management, and can also reduce the worm burden. Bats eat numerous flies and beetles so a healthy population of prey means a healthy population of predators. Owls also consume large invertebrates such as Dor and Minotaur Beetles so manure is a great starting point for increasing wildlife!
It’s the same with most things where we find ourselves working against nature: it’s much better to create a balance and find a way of utilising the natural nutrient-cycling facilities rather than simply trying to eliminate or eradicate problems.
Landowners and livestock managers can help dung beetles by implementing the following actions.
Varied diets for livestock
Dung beetles need a well-formed pat in which to make their tunnels and burrows, and to make the balls on which to lay their eggs in burrows. As they eat the plant material, having a variety of vegetative matter provides greater nutrients for the growing larvae, and will also aid in seed dispersal as many seeds pass through an animal’s gut unharmed, providing food for birds.
Avoid blanket use of wormers
Faecal egg counts can determine the actual worm burden on livestock, and avoid the need for dosing the whole herd with a set amount, regardless of how much is necessary for the individual animals. Quarantining any animals that do require parasite control for a few weeks will also prevent the beetles being in contact with the dung. Rotating the animals to be medicated will mean there is always some “clean” dung available for the nutrient-cyclers (earthworms, dung flies, fungi).
Mosaic of habitats
As mentioned before, this will provide the herbivores with different grazing and browsing opportunities; they will often seek out certain plants for parasite control if given the chance too. On a practical level, some species of dung beetle require shady conditions, so allowing livestock to be among trees can be helpful for beneficial insects, as well as providing protection from the elements for the stock.
Keep the land stocked all year round
Different species of dung beetle are active at different times of the year, so the modern practice of overwintering stock inside means there are many months where no food is available for the beetles. This ties in with broader grassland management techniques for good soil health such as rotational grazing and silvopasture, but it’s good to know that these methodologies also benefit the invertebrates.
Advocacy and citizen science
Championing our native dung beetles, and encouraging conversations with landowners and stock managers increases awareness about how this “waste product” is a hugely valuable resource, and rather than polluting waterways or causing storage and disposal issues, it can be utilised effectively by natural processes.
With all this in mind, I made some illustrated notes of the webinar. I would love to do graphic recording/live illustration for the rewilding/regenerative farming sector so I am getting in some practise with these excellent webinars from the Sussex Wildlife Trust.
