Science Alert 20 Apr 09;
University of Sydney "Researcher shows it makes ecological sense to eat roo"
A comparative study of the energy requirements of kangaroos and sheep has given new weight to calls for the increased use of roos for everything from eco-tourism to human and pet food consumption.
Dr Adam Munn from the University's School of Veterinary Science spent weeks tracking kangaroos and recording their energy requirements, concluding that kangaroos have far less of an impact on the environment than once thought.
"We found that the kangaroos were consuming only around 13 per cent as much water per day as sheep," said Dr Munn. "A sheep's diet consists mainly of saltbush. Sheep feeding on saltbush will drink around 12 litres of water a day, as opposed to kangaroos, which drink around 1.5 litres per day," said Dr Munn.
The study also shows that kangaroos consume around one-third of the energy of sheep and therefore have much less of an impact on the environment.
The researchers used isotopes to compare the animal's energy requirements which were introduced into the animals, with a blood sample taken after 10 days. The animal's energy levels were then calculated by comparing the quantity of remaining.
"This showed that the kangaroo will turn over around 5000 kilojoules per day, with sheep turning over around 15,000," said Dr Munn.
As kangaroos have significantly lower energy requirements than sheep, this indicates that they need less food than sheep, thus their environmental impact is lower.
"With climate change, most rangelands are going to need to look at diverse options for land management for sustainability," said Dr Munn. "It is conceivable that we could drought proof the environment more efficiently by using kangaroos for eco-tourism without the environmental impact once thought, or increase the use of kangaroo human or pet food consumption."