After observing a kangaroo limping in a creek bed with paws burnt by bushfires, wildlife volunteer Janine Green takes the decision that she never wants to make.
The loud crack of a rifle rings out across the barren, fire-blackened farmland in southeast Australia. The kangaroo slumps to the ground.
"Sometimes, it's inhumane to keep them alive," said Green, 55, a veterinary nurse for 25 years and now an animal rescue volunteer in New South Wales, which has borne the brunt of fierce fires in recent months.
"If we hadn't been here today he would have slowly lost weight, he's not in a position to be able to move."
Green was responding to a call from a farmer whose land was decimated by blazes that ran out of control last week.
The kangaroo had no fresh grass to eat and no water, and its wounds would most likely have turned septic.
"He would have had a slow, painful death," she added.
The bushfires that have torn through vast swathes of southeast Australia have left 26 people dead and killed or injured an estimated one billion animals.
The infernos were compounded by last year's highest temperatures on record, and tinder-dry conditions from three years of drought.
Wildlife groups have been scrambling to rescue animals suffering burns or starving.
On the farm just outside Cobargo, a town decimated by the fires, Green navigates a hill of scorched soil and charred trees to observe a sitting kangaroo that has made no attempt to move.
As she approaches, she sees a Joey inside its pouch. The female kangaroo, a burnt paw on one of its hind legs, quickly jumps away.
"She's able to hop away and get away from predators, which is what we worry about," Green said. "We'll leave her alone."
Australia's vast bushland is home to indigenous fauna like kangaroos, koalas, wallabies, possums, wombats and echidnas, but experts warn their days are numbered if climate change is not taken seriously.
"While Australian animals have evolved to survive fires, they haven't evolved to survive this scale and intensity and frequency of fires that we are going to see," said Ross Crates, an ecologist at the Australian National University in Canberra.
"If all of the foliage is burnt then basically they have no food. So in those instances it's most humane to put animals to sleep rather than have them suffer either through terrific burns or starvation."
Green runs a motel as well as volunteering for the country's Wildlife Information, Rescue and Education Services (WIRES).
She takes pride in the threatened creatures that she has managed to save, including marine turtles, gliders and even penguins. On Thursday, she took in a possum and a wombat, both of them suffering from burns.
The kangaroos she has previously mechanized have been overwhelmingly from traffic accidents, she said, typically three each week. Since the fires, she has had to put down one or two kangaroos each day.
"How do I cope? I know they're not suffering no more," she said. "I do what I have to do and just remember what I saved."