Mary Anne Forster was attacked by a koala while walking her dogs. Photo: 7News. 
 
 A woman has been left bloodied and required a four-day stay in hospital after being attacked by a koala north of Adelaide. 
 
 But despite her injuries, she says she doesn’t blame the animal for the brutal attack. 
 
 Williamstown woman Mary Anne Forster said she was walking her two dogs a fortnight ago when they pulled her towards a koala at the base of a tree. 
 
 “Obviously the koala felt very threatened because it attached itself with its mouth, jaws, to my leg and bit very hard, bit very deeply,” she said. 
 
 After a struggle, she managed to break free. 
 
 “Because it wouldn’t let go, I put my fingers in its mouth and pried its jaws open to release my leg,” Ms Forster said. 
 
 The assistant principal hobbled more than two kilometres home and was then taken to hospital. 
 
 Ms Forster was taken to hospital after the koala bite. Photo: Supplied. 
 
 She needed 12 stitches. 
 
 “All wild animals have dirty bites and so it was a matter of covering with the antibiotics because it became very infected, it was very swollen and painful,” she said. 
 
 Environmental experts have warned people to keep their distance if they spot a koala out in the wild. 
 
 “Just leave them alone, certainly don’t let dogs go near them because they will fight back, they’ve got big claws and big teeth,” Dr Deb Kelly from the Environment Department said. ||||| A koala attack in South Australia left one woman, who was walking her dogs at the time, bitten and bloodied. 
 
 Mary Anne Forster took her two dogs for a walk two weeks ago and when they pulled her toward a koala at the base of a tree, 7News Adelaide reported Wednesday. The koala launched into an attack on the dogs, but Forster got caught in the middle. 
 
 “Obviously the koala felt very threatened because it attached itself with its mouth, jaws, to my leg and bit very hard, bit very deeply,” she told 7News. 
 
 The koala latched on to Forster's leg and would not let go, causing a bite that required 12 stitches. In a desperate attempt to get the animal off her leg, she put her fingers in its mouth to get it to release its jaw. It finally released its grip and she stumbled 2km home before being admitted to hospital. 
 
 The wound on Forster's leg. Image: 7News Adelaide 
 
 Although koalas and dogs have a history of fighting, with 110 koalas killed each year by dog attacks, it is rare for a humans to be involved. 
 
 "It should also be remembered that koalas are capable of defending themselves. They have sharp teeth and claws capable of causing deep wounds and any dog that attacks a koala may risk serious injury," the Department of Environment and Heritage Protection states on its website. ||||| The mention of a koala bear often conjures up an image of an adorable spoon-nosed creature cocking its head to one side while clinging to a tree. 
 
 Now, scientists have figured out why the iconic Australian marsupials hug trees: The trunks help the koala bears keep cool, according to a new study. 
 
 "It can be a really useful way of getting rid of heat on a hot day," said study co-author Michael Kearney, an ecologist at the University of Melbourne in Australia. 
 
 Tree huggers 
 
 Given that koalas spend so much time in trees — the marsupials live in Australia's woodlands where they munch on leaves and sleep — nobody wondered why they hugged the trunks. People just thought they were taking a break on a more stable spot after eating leaves in the branches, Kearney said. [Marsupial Gallery: A Pouchful of Cute] 
 
 As such, the discovery came as a surprise. Kearney and his student, doctoral candidate Natalie Briscoe, were trying to predict how the woodland creatures on French Island, near Melbourne, would regulate their body temperatures as the continent heats up due to climate change. The region is cool most of the year, but during the summer, the temperature routinely spikes above 104 degrees Fahrenheit (40 degrees Celsius), Kearney said. 
 
 Briscoe measured wind and shade levels using a portable weather station, but didn't find any striking trends. Then she pointed to an infrared thermometer, which measures temperature based on thermal radiation, at the tree trunks the koalas were hugging. The trunks were considerably cooler than the ambient air temperature — sometimes by as much as 9 degrees F (5 degrees C), Kearney said. 
 
 She also noticed the koalas clinging to acacia trees, even though they normally eat eucalyptus leaves. [See Images of the Tree-Hugging Koalas] 
 
 "As it got hotter the koalas went farther down the trees and started to really hug onto the tree trunks," Kearney told Live Science. "That seemed strange to us until we figured out that the trees are a bit cooler." 
 
 Stay cool 
 
 Koala bears pant to keep cool, letting evaporated moisture from their mouths carry heat away from their bodies. 
 
 When the team modeled koala bear heat transfer, they found the tree-dwellers save half the water they would have used panting if they hug trees instead. 
 
 Koalas get most of their water from their diet, but because eucalyptus leaves are laced with a toxin, the koalas can eat only a limited amount before the toxin harms the animals, Kearney said. 
 
 So tree-hugging could be critical to their survival on hot days, by allowing them to cool off without wasting precious water through panting, Kearney said. 
 
 It's not clear exactly why their preferred tree trunks are cool, but one possibility is that they pull in a lot of groundwater, which stays closer to the annual average air temperature, rather than the current air temperature, he said. 
 
 Climate change planning 
 
 Koalas' food (and hugging) trees will change their range with the hotter and drier weather brought by climate change, Bill Ellis, a wildlife researcher at the University of Queensland in Australia, who was not involved in the study, wrote in an email to Live Science. 
 
 But the new study suggests that food may be a smaller consideration in preserving koala habitat than previously thought, he said. 
 
 "As long as we plant trees koalas will eat, perhaps the other trees we plant just need to provide the right mix of shelter and heat sink characteristics," Ellis said. "It's quite an interesting concept, but non-native trees might be the future for koalas — as long as they also have the right fodder." 
 
 Farther north in the koala's range, the air is muggy and it feels hotter, so scientists should see how tree-hugging plays out in in different locations in the koala's habitat, Ellis said. 
 
 "Humidity means that the power of evaporation for cooling is reduced," Kearney said. So tree-hugging may be even more important up north, where evaporative cooling doesn't work as well, he said. 
 
 The study was published today (June 3) in the journal Biology Letters. 
 
 Follow Tia Ghose on Twitter and Google+. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science.
– It wasn't the koala's fault, says an Australian woman who was savaged by one of the planet's cutest and most cuddly-appearing creatures. According to 7News Adelaide, Mary Anne Forster was walking her two dogs a couple of weeks ago when they dragged her toward a koala at the bottom of a tree; she got caught in the middle when the koala attacked the dogs. "Obviously the koala felt very threatened because it attached itself with its mouth, jaws, to my leg and bit very hard, bit very deeply," she says. Forster, who had to put her fingers in the koala's mouth to make it let go, needed 12 stitches and spent four days in the hospital after the attack. The bite "became very infected, it was very swollen and painful," she says. The koala had good reason to feel threatened, Mashable reports: Australian authorities estimate that 110 koalas are killed in dog attacks every year, and an environmental department spokesperson warns that people who see them in the wild should "just leave them alone—certainly don't let dogs go near them because they will fight back, they've got big claws and big teeth." (Scientists using thermal cameras have discovered why koalas hug trees.)