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  • Somewhere near you, an animal is defecating.

  • In fact, each day, the animal kingdom produces roughly enough dung to match the volume of water pouring over the Victoria Falls.

  • So why isn't the planet covered in the stuff?

  • You can thank the humble dung beetle for eating up the excess.

  • Capable of burying 250 times their body weight in a single night, these valiant insects make quick work of an endless stream of feces.

  • Over 7,000 known species of dung beetle run clean-up duty across six continentseverywhere except Antarctica.

  • A dung beetle's first task is to locate dung.

  • Some live on the anal regions of larger animals, ready to leap off when they defecate.

  • Others sniff out feces that animals leave behind.

  • A pile of elephant dung can attract 4,000 beetles in 15 minutes.

  • So once a beetle finds dung, it must work quickly to secure some of the bounty for itself.

  • Most dung beetle species fall into one of three main groups: rollers, tunnelers, and dwellers.

  • Dung rollers sculpt a ball of dung, and using their back legs, quickly roll it away from competitors.

  • Potential partners jump on the ball, and once the ball-maker has selected their mate, the pair dig their dung ball into the soil.

  • Once it's been buried, the female lays a single egg within the dung ball.

  • Tunnelers have a different approach.

  • Digging underneath a pat, some drag dung down into the soil and pack it into clumps known as brood balls, dung balls, or dungsausages,”depending on their shape and size.

  • Male tunnelers sport a spectacular array of horns to fight each other for control of these tunnels, which they then defend until the females laid her egg.

  • Some male tunnelers avoid the fray by masquerading as hornless females and sneaking into tunnels to mate while the guardians' heads are turned.

  • The third group of dung beetles: dwellers, take the most straightforward approach, laying their eggs directly into a dung pat.

  • This makes their offspring more vulnerable to predation than those of the tunnelers and rollers.

  • As the larvae feed, they riddle the dung pat with tunnels, leaving remains that are quickly colonized by bacteria and fungi and weathered away.

  • Inside a tunnel, ball, or pat, once the larvae hatch, they consume the dung before metamorphosing into a pupa and then an adult beetle.

  • Besides clearing dung, the actions of these beetles have considerable ecological importance.

  • For one, they serve as secondary seed dispersers.

  • Dung from monkeys, wild pigs, and other animals is riddled with seeds from the fruits they eat.

  • When beetles bury their dung balls, they inadvertently protect these seeds from predators and increase the likelihood they'll germinate.

  • The advantage is so great that one South African plant has evolved to produce seeds that look and smell like dung to trick beetles into burying them.

  • Dung beetles also play important roles in agricultural systems.

  • Livestock, like cows and sheep, produce huge amounts of dung, which contains nutrients that can benefit plants.

  • The beetles break up the dung and tunnel it deep into the soil, bringing the nutrients into close contact with plant roots.

  • Their services to farmers have been valued at $380 million a year in the US and £367 million a year in the UK.

  • Dung beetles can even help us battle global warming by reducing greenhouse gas emissions associated with farming.

  • Microbes living in oxygen-poor livestock dung produce methane, a potent greenhouse gas.

  • But beetles oxygenate pats when they tunnel into them, preventing the microbes from producing methane.

  • The dung beetle spreads seeds, helps farmers and fights climate changeand accomplishes it all simply by doing its business.

  • Maybe next time you come across some dung in the forest or a field, you'll be tempted to take a closer look.

  • If you want to learn more about nature's pooper-scoopers, we highly recommend "Animal Weapons" by Douglas J. Emlen.

  • This book includes more wildly fascinating facts about dung beetles and digs deep into the survival strategy of animal's around the world.

  • Read our full recommendation and snag a copy by visiting ed.ted.com/books. Check out the comment section to learn more.

Somewhere near you, an animal is defecating.

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B2 H-INT US TED-Ed dung beetle pat ball tunnel

Why isn't the world covered in poop? - Eleanor Slade and Paul Manning

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    April Lu   posted on 2018/04/01
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