Kangaroos can no longer feel smug about their flatulence. Traditionally, it has been thought that the animals produce unusually low amounts of methane when they pass gas. Since livestock farts (I'm looking at you, cows) make up a lot of our global greenhouse gas emissions, that would make kangaroos potential lifesavers in the global warming department. Scientists had hoped that there might be some secret cocktail of microbes in their gut that made their emissions so delicate — perhaps one that could be given to cattle to make their farts less harmful.
But according to a study published Wednesday in the Journal of Experimental Biology, there's nothing magical about a kangaroo fart.
"The idea that kangaroos have unique gut microbes has been floating around for some time and a great deal of research has gone into discovering these apparently unique microbes," study author Adam Munn of the University of Wollongong said in a statement.
How does one measure kangaroo farts? You seal the animals up in individual rooms and feed them alfalfa. Some of the kangaroos were given a set diet, while others enjoyed an all-you-can-eat alfalfa buffet. Meanwhile, the scientists measured the methane accumulating in each kangaroo's room and analyzed their poop.
Kangaroos do produce less methane than cows, when you compare one individual to another. When the researchers looked at methane emissions in relation to food intake, however, they found that kangaroos actually come pretty close to cow methane production. In other words, if a cow had the same digestion microbes as a kangaroo, they'd probably produce the same amount of methane that they do naturally.
They also noted that kangaroos produce more methane when their food takes longer to digest. If cows digested their food as quickly as kangaroos typically do, the researchers suggest, they might emit less methane in the process. It's possible that the key to lowering cow emissions is breeding cattle that digest their food more quickly — not giving them doses of kangaroo microbes.
No kangaroos could be reached for comment, but we imagine they're wildly offended.