The iconic Australian marsupials are being crowded out of their native forests by human populations; and with this comes stress.
The stress is bringing out a latent disease that infects 50 to 90 percent of the animals.Read the full story: Stress-related disease killing off Australia's koalas
The problem came to national attention in August, when the well-known Sam the Koala (picture above) died during surgery to treat the disease, called chlamydia. Sam captured the world's attention during major wildfires in February, when she was photographed drinking from the water bottle of a firefighter in a smoldering forest.
Chlamydiosis is a virus that breaks out in koalas in times of stress - like cold sores in humans - and leads to infections in the eyes and urinary, reproductive and respiratory tracts. It can cause blindness, infertility and death.
Photo by Mark Pardew / AP