Sunday 6 October 2013

The Dung beetles of Nagarhole

They are classified as the strongest insects in the world. They can lift 1,141 times their own body weight. This is equivalent to a normal man pulling six double decker buses, each of them full of people.
They are a modern group as their fossils date back to 30 million years ago and as of now there are more than 7000 species worldwide.
They range in size from less than a millimeter to six centimetres or a little more. And they occur rather extensively in all the continents except Antartica.
They are the Dung beetles and India has hundreds of such species. Nagarhole in  Karnataka alone had nearly a hundred of these Dung beetles.
The Dung beetles found include Catharsius granulatus, Copris indicus, Oniticellus cinctus,  Onitis singhalensis, Onthophagus beesoni, Onthophagus ensifer, Onthophagus ranam, Onthophagus sp.107, Onthophagus tarandus, Picnopanaleus rotundus, Caccobius diminutives, Caccobius ultor, Copris furciceps, Copris sp,  Heliocopris dominus, Pseudonthophagus sp, Sisyphus neglectus, Caccobius inermis, Caccobius meridionalis., Caccobius torticornis, Caccobius sp, Copris sodalist, Onthophagus socialis, Onthophagus sp.301, Onitis phelemon, Onthophagus furcillifer, Caccobius gallinus, Onthophagus rufulgens, Onthophagus sp, Copris repertus, Pseudonthophagus sp.1, Copris davisoni, Onitis falcatus, Onthophagus turbatus, Copris imitans, Onthophagus quadridentatus, Caccobius vulcanus, Liatongus affinis, Oniticellus spinipes, Sisyphus longipus, Onthophagus dama and many others.
The Dung beetles live anywhere from three to five years. A researcher has found that a small 1.5 kilograms pile of Elephant dung on the African Savannah attracted 16 000 Dung beetles, who between them had eaten and or buried that dung completely in just two hours.
Research has also shown that one dung beetle can bury 250 times its own weight in a night. Most of the Dung beetles prefer herbivore dung, though many are not very particular and will use many different forms of dung,
Some species have a definite preference for one type of dung only.
Onthophagus caenobita has only ever been found feeding in human faeces. Similarly, the Zonocopris gibbicolis of South America feeds on the faeces of large snails on whom it rides around.
The female dung beetle lays a single egg into each ball of dung and then covers the nest with more dung and soil. When the eggs hatch, the larvae feed on the fecal matter.
Dung beetles can be divided into three groups: Rollers, Tunnellers and Dwellers. Rollers make a burrow some way away from the dung they are going to use and then collect small to medium sized lumps of dung to roll into their burrows. Typhaeus typhoeus, the Minotaur Beetle, can dig burrows up to a metre deep. Generally the female does most of the digging and the male spends most of his time foraging for dung and collecting it for her.
Rollers dig their front legs into the ground and use their hind legs to push the ball of dung. Tunnellers fly until they find some fecal matter into which they straightaway dive. They then dig a tunnel and then drag as much dung as they like down into it. Again it is mostly the female who stays in the burrow sorting out the dung and the male goes out to get it.
Some dung beetles eat and lay their eggs on dung some other beetle has collected. This thief beetle often eats the legitimate dung-owners eggs apart from taking away or stealing their dung.
The females of many of the larger ‘Rollers’ stay inside their burrows and care for and protect their eggs and young. They can live for up to three years. Some of these larger dung beetles can move balls of dung (on the ground ofcourse) up to 50 times their own weight.
Not many know that Australia imported 45 species of dung beetle from various parts of the world to get rid of cattle dung.
In ancient Egypt the dung beetle was called Scarab and it was an important religious symbol. In some Indian tribes from South America, a dung beetle named Aksak is supposed to have modelled the first man and woman from clay.
Are dung beetles important to evolution. What is likely to happen if they are not there in the world. Without dung beetles, the Earth would be piled high with manure and dung.
The dung beetles  feed on dung and they spend quiet a time in a day eating faeces. They are, therefore, called as Dung beetles.
Since they spend their days eating faeces, their dungrolling led the ancient Egyptians to believe they were responsible for keeping the sun moving.
More than a hundred species of  dung beetles can be found in the Nagarahole (Rajiv Gandhi) National Park, which is ranked among the richest biodiversity spots in the country.
The  Heliocopris Dominus is the biggest dung beetle in the country and it was generally found in the north-eastern region. This species too is found in Nagarhole.
Watching the dung beetle is as fascinating as it can be. Want to check it. Then head for Nagarhole. You are sure to come across them wherever you find dung. And Nagarhole is home to one of the largest elephant herds in India. You can easily spot the Heliocopris dominus which breeds only in elephant dung and Onthophagus pactolus, a very rare species of dung beetle. Of course, you can easily spot Onthophagus dama, the most common dung beetle.    

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