Every organism has its role in nature but
perhaps none are more important than
the much loved dung beetle. Its role as
the bush sanitation engineer has raised its lowly profile to gargantuan
proportions and every safari goer gleans as much pleasure from watching their
ball rolling antics as they do from seeing the mighty elephant. Dung beetles are split into 4 main groups
dependent upon their egg laying strategy.
The telecoprid dung beetles are the most famous and are often seen rolling
their disproportionately large trophies across the bushveld.
There are many different species but the
most common behaviour seems to involve the male making a ‘food ball’, hoping
that his architectural prowess will attract a potential mate. Once a female has approved the construction
of the dung ball the male rolls it to a suitable site (whilst the female
hitches a free ride!) and sinks it into the ground where the pair then consume
the ball and mate for the first time – not everybody’s idea of a romantic
dinner-for-2 but the animal kingdom is full of variety!
Whilst the female gestates her eggs, the male
locates another deposit of fresh dung and fashions a ‘brood ball’ that he dutifully
rolls back to his pregnant bride. Such
are this diminutive creature’s navigation skills, it can relocate the nest from
over a mile away! One can often see them
scaling their mighty cargo to orientate themselves with the Sun, their
specially adapted eyes even able to do so on cloudy days.
Once more he sinks the ball into an underground
chamber and here the female lays an egg inside his mobile larder. She then meticulously smoothes the outer
surface, much like a plasterer would finish a wall, in order to harden the outer
shell and cocoon her offspring. It also prevents
the dung within from drying out and thus ensures a good supply of food for the
larva. The egg will hatch shortly and the young larva will spend the next few
weeks systematically consuming the contents of the ball until it has absorbed
enough nutrients to begin the process of pupation and ultimately emerge as an
dung beetle.
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Remains of "brood balls" |
These grubs are however a great source of
protein and are relished by all sorts of predators and even humans. The biggest threat to a dung beetle larva is
the honey badger and it is common to find the hollowed out remains of these
brood balls littering the bushveld. Many
larvae reach adulthood however and their role in nature abounds. Not only do they recirculate the nutrient
rich dung, but play a huge role in seed dispersal, literally planting the many
seeds that emerge undigested from the digestive tracts of many herbivores. They also contribute massively in controlling
parasite numbers as countless fly eggs are sunk into the ground along with
these balls and thus never see the light of day. Such is their ecological importance that
Australia as imported dung beetles from Africa in an attempt to control the fly
population in the country due to an excess of cattle dung – not a bad CV for
one of the unsung heroes of the African bush!
Wildlife fact and photos by: Ben Coley
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