For a long time, there’s been debate about just how much methane kangaroo’s produce – and now we know thanks to research led by Dr Adam Munn from the University of Wollongong’s Institute for Sustainable Ecosystem Solutions and Professor Marcus Clauss from the University of Zurich’s Clinic of Zoo Animals, Exotic Pets and Wildlife.
“We knew that the kangaroos would produce little methane, but certainly not zero, and the question remained as to why,” Dr Munn said.
"Methane release into the atmosphere plays a significant role in the production of greenhouse gas emissions which is a critical factor leading to global warming."
“The main hypotheses behind kangaroos producing little methane have focussed on kangaroos having a unique microbiome that produces less methane, mainly from flatulence rather than burping like cows and sheep. But, without wanting to burst the bubble of the microbiologists, our findings suggest otherwise.”
The team measured an absolute methane output in kangaroos comparable to that of horses, when corrected for body weight.
“Kangaroos have a very different stomach from that of ruminants such as sheep and cows,” Professor Clauss said.
“We think that the methane is low because of the way food moves through the kangaroo stomach, and not because of a unique gut fauna.”
These conclusions are based on the finding that that the amount of methane produced per ingested food varies even within kangaroos, depending on how much they eat. When fed restrictively, methane per unit food was nearly as high in some kangaroos as values in domestic ruminants.
The team’s important findings will be used to inform efforts to fight climate change.