Monday, October 18, 2010

Who Flung Dung

Click cartoon for a better image

New Zealand has every reason to be proud in its “Clean Green” reputation abroad. The rural sector has however, not such a good reputation at home when it comes to water quality. There is increasing evidence that animal waste, from the rapidly rising numbers of dairy farms, is putting pressure on the quality of our air and water supplies.

A lot of research effort is being directed to this problem and a recent proposal to try a very “clean green” solution is gaining government support. A grant of $400,000 from the Ministry of Agriculture and Fisheries (MAF) Sustainable Farming Fund is being used to investigate the impact of introducing Dung Beetles to clean up animal wastes.

In many countries, generations of Dung Beetles have been munching their way through cowpats for thousands of years. They are seen to be to be an effective way to remove animal wastes from the countryside and might be able to reduce the 80% loss of nitrogen on New Zealand farms down to 10%. Another useful plus will also be the reduction of drenching required to cope with flies and parasites.

Choosing the right species will be a complex and time consuming process and the MAF grant will last for three years. Performance will not be the only factor to be taken into account. Prospective Dung Beetles will have to satisfy the Environmental Risk Management Authority (ERMA) that there will be minimal detrimental effects on New Zealand’s ecology.

Dung Beetles can be usefully classified into three groups: tunnellers, rollers and dwellers. Tunnellers obviously bury their precious booty underground and lay their eggs there. Rollers make dung balls, move them somewhere else and stay to guard their young from rivals and predators. Dwellers like to stay at home where the food is and some species have been seen to use polarized light to navigate around the pasture.

We could soon be seeing some very interesting beetles in our gardens after they are released into the Rodney District. Some Dung Beetles are very colourful and others, like Rhinoceros Beetles, are particularly horny. Local craftspeople might even be inspired by them to try new designs. The Ancient Egyptians revered Scarab (Dung) Beetles as symbols of resurrection, which is why these beetles appeared on their beautiful jewelry.

Most Dung Beetles go after herbivore waste but a few have got adventurous enough to get a taste for primate and human dung. Who knows, farmers near tourist localities might one day be able to employ some of these Dung Beetles to clean up the stuff that freedom campers leave behind.

Research scientist Hugh Gourlay has been reported to say that Dung Beetles will bring, “One of the biggest changes to our farm management since we first imported cows into this country.” If he is right, then hopefully it will no longer be necessary to ask ‘who flung dung’ into our waterways and we will keep our environmentally friendly reputation that gives farmers a price premium in world markets.

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