In the early morning hours when the forest is cool, something strange glows on thermal drone footage — the warm bodies of koalas tucked away in the trees of the Brisbane Koala Bushlands at Burbank. What used to take researchers days of trudging through thick bush with torches has been reduced to a simple flyover.

"We get up early in the morning when there's really good differential between the cool forest and the koalas' heat, and the thermal camera on the drone just glows if you happen to fly over a koala," said University of Queensland researcher Dr. Sean FitzGibbon. "This is way more efficient and means we can get a lot more done."

Eight years ago, finding koalas meant spending days walking in a line through the bush, shining flashlights upward hoping to spot the reflective shine of their eyes. Now, researchers can detect multiple koalas in a single morning.

The real breakthrough, though, comes from tiny solar-powered tracking collars weighing just 20 grams. These lightweight devices send a koala's location to a researcher's phone about four times every day. When a signal shows an animal has stopped moving or seems off, the team can rush out to help.

"A few times it's saved koalas' lives where we found a sick koala that might've died in a few days if we hadn't responded to the GPS signal," Dr. FitzGibbon said. "It's an important advancement in animal welfare."

The technology is part of a larger effort to rescue a koala population that has been crashing for decades. The program, running for 18 months, brings together the Brisbane City Council, Queensland government, wildlife rescue groups, and animal hospitals. At Burbank, researchers are fighting chlamydia — the biggest threat to koalas in the area — and working to strengthen the population by treating sick animals and introducing healthy young koalas as new breeding stock.

Dr. Amber Gillett, a veterinarian and research fellow, runs health checks on every koala found, right there in a retrofitted caravan that serves as a mobile vet clinic. She can draw blood, use a microscope, and run tests without stressing the animal by transporting it to a hospital.

"I have a really good handle on what's going on with the koala," Dr. Gillett said. "That reduces stress on the koala and reduces the impact on the wildlife hospitals that are always really busy."

One of the relocated koalas, a young female named Deliah, came from Whites Hill Reserve after being rescued from dangers like busy roads, backyards with dogs, and swimming pools. She and others like her are now wearing those solar-powered collars, their every move tracked as they settle into their new home.

So far, the 18-month effort has already seen two joeys born — tiny babies emerging from their mothers' pouches — a sign that the population might finally be turning around.

"We bring in the right animals and we give them the environment and they can do it themselves," Dr. Gillett said. "They will bolster their own population."