The insect world is often only considered a nuisance when on safari, the nasty mosquitoes nibbling your ankles or the irritating flies buzzing around your face, but we should look further than these irritations to the other members of this tiny creature world.
One of the most fascinating insects in the bush is the loosely termed Dung Beetle. These creatures belong to the Scarabaeoidea super family which consists of 5000 species, and are found on all continents except Antarctica. These guys will use their excellent sense of smell to find the freshest dung, while some of the smaller species will just hitch a ride on the animal and wait for them to deposit their pile. They will eat and use dung from both herbivores or omnivores, but some species are very particular about eating or using the dung from a certain animal species. Recent research at the University of Nebraska suggests dung beetles may be most attracted to omnivore excrement, since it provides both nutritional value and the right amount of odor to make it easy to find. The attraction in the dung is the semidigested grass and the excreted liquids that they feed on. The beetles have specialized mouth-parts to extract the liquid which contains microorganisms and other nutrients, so finding the freshest dung is very important. Dung beetles can roll up to 10 times their weight. Male Onthophagus taurus beetles can pull 1,141 times their own body weight: the equivalent of an average person pulling six double-decker buses full of people!! This family of invertebrates can vary in colour from iridescent blue to black to copper, depending on the species and can live about 3 years.
In this huge family, there are the 4 general categories of dung beetles, ‘the rollers’, ‘the tunnelers’, ‘the thieves’ and ‘the dwellers’, they sound an interesting lot don’t they? The Rollers, (Telecoprid) are the iconic dung beetles, seen rolling their ball of dung backwards with their hind feet at impressive speeds. The Tunnelers (Paracoprid), will tunnel under a pile of dung, dragging and pushing these fresh provisions down into their tunnels to use in their nest. Tunnels have been found of over a metre long. The Thieves (Kleptocorprid group) will push other dung beetles off their ball of dung and steal them, avoiding the hard work of forming the ball and will lay their eggs in the hosts balls. The final group of dung beetle are the Dwellers (Endocoprids) who don’t go to all the fuss of rolling, digging or tunnelling and will just lay their eggs in the pile of fresh dung.
When the larvae hatch, they eat the still moist dung, pupate into adult beetles and emerge from the nest to fly off in search of a fresh pile of dung. Some species of dung beetle are considered good parents, with the parents not leave after laying the eggs, but remaining to safeguard their offspring.
Not only are these creatures super strong but they are also incredible navigators! A species of dung beetle (the African Scarabaeus zambesianus) navigates by patterns in moonlight, the first animal known to do so. Dung beetles can also navigate when only the Milky Way or clusters of bright stars are visible, making them the only insects known to orient themselves in this way. These creatures are the cleaners of the insect world, clearing the piles of dung away, burying it to regenerate the soil with its nutrients and improving the soil structure with compost. They aid in seed dispersal, helping germination of new plants from the remains in the animal dung, and help keep the breeding grounds of pests like flies down to a minimum dung removal. They are good bioindicator creatures, and are used to examine the impacts from human activities on tropical biodiversity and ecosystem functioning, such as seed dispersal, soil bioturbation and nutrient cycling.
So the next time you are in the bush and hear that loud buzzing sound of the dung beetle flying by, remember his intricate roll in our environment and the interesting family members he has.