Koalas on the outer live life differently
Friday, 13 September 2013
Katie Silver
- ABC
Koalas living in the eastern parts of the range rely on the moisture of their leaves for water(Source: Josh Berglund/Flickr)
Related Stories
Koalas reject rehab field of dreams, Science Online, 20 Feb 2013
Koalas added to threatened species list, Science Online, 03 May 2012
Island koalas too close for comfort, Science Online, 20 Oct 2009
Koalas living on the outskirts of a forest are pickier and greedier when it comes to choosing their real estate.
That’s according to new research published today in the journal Movement Ecology, which finds koalas behave very differently based on where they live, and that a ‘one-size-fits-all’ strategy for conservation won’t cut it.
“The threats change between the different regions – and if their threats aren’t the same then their behaviours are likely to be changing too,” says the study’s lead author Nicole Davies, a PhD candidate in landscape ecology at the University of Queensland.
Davies and her colleagues attached GPS collars to 21 koalas and radio-tracked them for up to five months.
The research area, located in southwest Queensland, covers 200,000 square kilometres and spans three different bio-regions, and is more arid in the west than in the east.
The researchers found that koalas living on the fringe of their natural habitat spend most of their time closer to rivers or drainage lines.
“Further east the koalas tend to rely on the moisture of their leaves, whereas western koalas need to come down to drink the water from the dams and waterholes,” says Davies.
This means the edge populations are more selective about where they set up home and need to travel more each day to find the food and resources they need.
Zigzag travels
The study also found that in semi-arid regions – where annual rainfall was higher and there was more freestanding water – koalas travelled shorter distances each day and did so in a zigzag pattern.
However this changed for the males of the species if there was a lot of rain in the short-term.
If over two months there was a lot of rain, male koalas would travel larger, more linear distances each day, Davies says. “The increased rainfall improves the quality of the habitat and they use this window as an opportunity for breeding.”
With very different ways of living in the environment there can’t be just one approach to conservation, the study finds.
“In the west, conservation requires moisture,” says Davies pointing to rainfall and freestanding water as the major concerns. “Further east habitat loss, dogs and vehicle collisions are the driving threats.”
The researchers add that the ability of these fringe-dwelling koalas to cope in an arid climate suggests they could be better adapted to climate change, which might prove important for the long-term survival of the species.
Tags: conservation, animals, marsupials
Source : http://www.abc.net.au/science/articles/2013/09/13/3847456.htm