Dung beetles and the stars …did you know?

Dance of the Dung Beetles by Marcus Byrne and Helen Lunn

“Biology and history dance with the scarabs” Description by Jane Carruthers, Emeritus Professor, Department of History, UNISA

There is a lot that is special about this book – firstly it’s ‘an entomological page turner’ .. now that’s a first! Increasingly the meeting of art and science is becoming a hot topic in the academic arena and it is the highly unusual writing partnership which makes this book both so informative and so readable. Marcus Byrne is Professor in the School of Animal, Plant and Environmental Science at the University of the Witwatersrand and Helen Lunn has a PhD in Musicology.  The main protagonist of their story provides the authors with rich subject matter as the dung beetle is a quite extraordinary little animal. Marcus Byrne is well qualified to write about dung beetles as he has studied them for 30 years. But what gives this book its broad sweep is the way the authors trace human attitudes to dung beetles over the last seven thousand years. In doing so they offer an understanding of how humankind has viewed the world through the ages and also map the history of the development of science.   And all through this little creature which spends its life in piles of poop. 

Did you know ….

1. the dung beetle’s significance in creation myths?

The dung beetle features in the cosmogony (origins of the universe) of many ancient peoples in South America, Indonesia and of course the Egyptians. In ancient Egypt the dung beetle was embodied in the god, Khepri, a creature with human body and scarab head. 

It was believed that Khepri rolled the sun across the sky to bury it at sunset, and then dug it back up in the east at dawn, just as the dung beetle rolls his dung which then transforms with new life when young beetles emerge from the pupas.

2. dung beetles might have existed with dinosaurs?

A study at the Cleveland Museum of Natural History indicates that dung beetles evolved in association with dinosaurs (115-130 million years ago) and that, having survived the mass extinction 66 million years ago, they then went onto diversify at their greatest rate in tandem with the diversification of mammals. Fossilized dinosaur poop from 70 to 80 million years ago shows evidence of tunneling attributed to dung beetle feeding. 

Dung beetles categorized. Cleveland Museum of Natural History

3. they can roll their prized balls of poop (backwards and heads down) in a consistently straight line?

Scientists had known for some time that beetles active during the day follow a straight line as they roll there prize away. A quick and direct getaway from the larger dung heap is vital in order to find  a safe spot as quickly as possible to bury the precious ball underground.  And of course not to end up back at the dung heap. Researchers surmised they were orienting themselves  by the sun.  Periodically a beetle will stop rolling, climb on top of its booty, and move around to orient himself before climbing down to carry on pushing. 

4. how scientists tested this?

But how to prove it? It’s tricky to get a dung beetle to stop looking at the sky. So they made little peaked caps for their heads and sure enough when they could not see the sky, the little critters pushed their load round and round in aimless circles.  

The researchers put little cardboard caps on the beetles’ heads, blocking their view of the sky. Those beetles just went round and around in circles until the caps were taken off and then they beetled off on their exact same straight course again … after a little orientation dance

But what about those beetles active at night?  From 2003 Byrne had been meeting annually to study dung beetles with a group of scientists from Sweden, Australia, Germany and South Africa in the South African bush. By 2009 they knew that these animals were able to orientate by the polarized light of the moon. But what when there was no moon? The researchers were convinced they were using the stars to orientate themselves. But now how to find out which bit of the sky they were using?  At that stage it seems that, along with humans, only seals and a few species of birds were known to orientate by the stars.  So off to the Johannesburg planetarium went a group of study beetles and gradually, by systematically removing elements of the simulated night sky, the scientists were able to conclude that the Milky Way is part of their nocturnal compass.  These small creatures orient themselves by the polarized light of the very centre of our galaxy. 

Only 800 of the 2000 species of dung beetles roll their poop
Watch David Attenborogh’s video for live Kung-fu action

5. how many species of dung beetles there are?

There are around 6000 species of dung beetles currently known in the world. Dung beetles are found on every continent except Antarctica. Of the 6000, 2000 are found in Africa. 

6. not all dung beetles roll their poop?

In addition to rollers there are tunellers who tunnel below the poop and make a nest there. Dwellers simply live in the poop and stealers … well they just wait for another critter to do all the hard work and then try and pinch it. 

7. dung beetles are fussy fussy eaters?  

Who would have thought that dung beetles that feast on dry fibrous ‘roo dung wouldn’t immediately see soft wet cow dung as a delicacy? Not so. As the numbers of livestock increased in Australia (the first cattle were introduced in 1788), and the Ozzie beetles refused to clear up after foreigners, the uncleared poop became a huge problem. By the 1950s billions of flies feasted on the dung and it also ruined millions of hectares of grazing land. Byrne and Lunn discuss the Australian Dung Beetle Project at length (pp 92-102) which started in 1968 with the introduction of alien species of dung beetles which clear livestock dung – initially 275,000 dung beetles (4 species).  To date 1.7 million dung beetled have been released across the continent with very impressive results.

8. Victorians wore real dung beetles as jewelery

In looking for a picture for this I googled “dung beetles Victorian jewelry” and was amazed by what came up from Victorian times to the present day.  With the building of the Suez Canal from 1859 to 1869, the interest in and influence of Egypt impacted on much of Victorian design and symbolism. It seems the somewhat bizarre fashion of insect jewelry was driven by the beautiful colours of many of the insects, the interest in nature in an age of increasing industrialization, and, in the case of the scarab, its association with resurrection  and status as a good-luck amulet.

This is a broach using a real dried dung beetle – dates to the 1870s
Real Scarab earrings also 1870s
Vintage dung beetles in glass cabochons on a black bow setting

 

 

 

 

 

 

 

But what seemed most bizzare of all was the practice (albeit not widely fashionable) of sewing real insects into clothing or keeping “live” insects in little gold cages attached to chains and brooches.  Clearly these caged insects did not remain “live” for long.  The Punch cartoons below satirize the bizarre Victorian and Edwardian fashion of both real insect jewelry as well as dead stuffed animals like lizards and minks’ heads as items of adornment!  

Courtesy: Punch Oct 7 1871 p 141; April 9 1969 p 144; Nov 30 1967 p219

9.  dung beetles can roll dung 50 times their own weight.

One specific species can pull a dung ball 1,141 times their body weight. This is equivalent to a human pulling six double-decker buses full of people…

10. dung beetles cool their feet on their dung balls  

Probably because of the water content, dung balls are cooler than the surrounding environment. When the ground gets hot the sensible cool their toes in the poop. Scientists put silicone “shoes” on the dung beetles and found that those with ‘shoes’ took fewer breaks and managed to push their balls for longer. 

A dung beetle wearing silicone boots in an experiment to test the effect of hot sand on its ball rolling and thermoregulatory behaviour. Courtesy: Marcus Byrne

This fascinating book about both dung beetles and their habits and how humans have viewed this animal over the millenia, is highly recommended.  

Liz at Lancaster’s Lapis Lazuli Scarab amulet from a visit to Egypt in 2000

 

 

 

 

 

 

 

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