The Next Weapon In The Battle Against Climate Change: The Dung Beetle

dung-beetles-and-climate-changeWhat comes out of a cow and sounds like a bell? DUNGGGG!

Dung beetles immerse themselves in shit to feed. The Dung Beetle Release Strategy Group (DBRSG), comprising farmers and other interested parties, is seeking permission to release 11 foreign species of dung beetle in New Zealand in order to reduce emissions of that potent greenhouse gas, methane.

Dung beetles bury dung between 12 and 24 inches down and lay eggs in it. This dissemination improves the condition of soil. One reason is aeration: methane springs up in anaerobic – airless – conditions. Another is that such soil also receives better water penetration, reducing the need for fertiliser. The eggs of parasites are taken where they can’t hatch. Andrew Barber, a spokesman for the group, described dung beetles as “basically the ideal farm worker.”

The methane produced by agriculture is a serious issue, as more greenhouse gases are emitted – up to 14 percent of the total – than by the transportation industry, per the United Nations. A paper by Tomas Roslin and colleagues at the University of Helsinki that was published in the journal, PLoS ONE, studied whether dung beetles could reduce the methane emanating from cowpats, finding that 40 percent less methane was thus generated. Said Roslin, “If the beetles can keep those methane emissions down, well, then, we should obviously thank them – and make sure to include them in our calculations of overall climatic effects of dairy and beef farming.”

Anything that lessens the prevalence of dung is a good thing, as cattle have taken the adage, “Don’t shit where you eat,” to heart, and don’t feed near it. Hugh Gourlay, a senior research for Landcare Research, which is involved with the DBRSG’s endeavour, made the startling revelations that five percent of productive land is estimated to go ungrazed because of dung, but dung beetles can remove a patty in as little as 24 hours, converting it to sawdust.

In the past, the introduction of foreign species has caused great upset to New Zealand. Possums were brought to the country by the fur trade in the middle of the 19th century and were protected from all but licensed hunters until 1938, but are now the country’s most serious pest, with over 65 million believed present in the 2000s. Rabbits are cute but the second-greatest pest. Ushered in in the 1930s for sport, they now compete with livestock for pasture and remove vegetation up to and including trees. They cost farmers and landowners millions of dollars.

Ruud Kleinpaste, an entomologist, doubted that dung beetles would cause similar ecological upset as they would have to compete with 17 native species, but felt caution was in order: “ERMA [the Environmental Risk Management Authority] will have some serious thinking to do.”

Dung beetles, alas, are in decline. In Finland, more than half of species are threatened or close to that state. This is due to the lack of diversity of dung and pasture concomitant with more intensively-managed farms. Dung also contains more chemicals, for instance anti-parasite drugs.

If the importation of dung beetles is approved, it would likely take between 15 and 20 years for effects to become evident. One more reason for the coolness of dung beetles is that, known as qiangland in Chinese, they are used in Chinese herbal medicine, where they are recommended as the cure for 10 diseases.

About the Author Timothy Chilman

Timothy Chilman used to work in IT. Once, in Sydney, he was turned down for a job because he was “too flamboyant” (“Someone who wears green tartan suspenders to a job interview probably isn’t going to fit in here”). Timothy then became an English teacher. University students in Bangkok complained that he was “too enthusiastic” and company students in Prague complained that he was “too theatrical.”

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