Dr Tony Friend spots it after days scrolling through images on his computer.
On his screen is a picture showing two small figures, captured in grainy black and white, on an island off the coast of Esperance.
They could be mistaken for any number of Australian bush regulars — rats, mice, or bandicoots.
Dr Friend stares for a moment, then yells excitedly, because the research associate with the Western Australia's Department of Biodiversity, Conservation and Attractions (DBCA) knows exactly what they are.
They are Gilbert's potoroos, a species that has been teetering on the edge of extinction for years.
Yet Dr Friend's state of elation is not due to their identity but their size, with one much smaller than the other.
It seems one of the world's rarest marsupial has been having babies.
Breeding 'going really well'
The Gilbert's potoroo was believed to have died out entirely until it was spotted for the first time in more than a century near Albany during 1994.
Researchers then set up a new population on Bald Island, off Albany, which proved critical when a fire wiped out most of the original population at Two Peoples Bay during 2015.
In 2018, another 10 were brought to Middle Island, off Esperance.
In November and February rangers from the Esperance Tjaltjraak Native Title Aboriginal Corporation (ETNTAC) went to the island to download data from motion sensor cameras, designed to monitor how the animals were faring.
While trawling through tens of thousands of captured images was hard work, Dr Friend said the result was worth it when he spotted a potoroo.
"You just go, 'Yay'," he said.
Dr Friend said the only way to differentiate between photographed individuals was by their sizes, so he could not tell adults apart.
But he said two images showed a trio of potoroos, two adults and a joey, and the joey in the second photo was much smaller than in the first.
"So they were different young potoroos," Dr Friend said.
Potoroos photographed in new location
He said the cameras were stationed at a place likely to have potoroos, a place unlikely to have potoroos, and a place with a medium-level chance of having potoroos.
As expected, the first picked up lots of potoroo images, and the second picked up none.
But, excitingly, the latter also picked up a potoroo image.
"That was a new site for potoroos," Dr Friend said.
"And [it was] outside the home range of the potoroos [photographed by the first camera], so that's definitely a different potoroo.
Dr Friend said trapping operations in the past had located six potoroos, and three of those were young at the time.
"We knew there was breeding happening," he said.
A 'most amazing privilege'
Before the end of the year, Dr Friend hopes to have some even more valuable information.
ETNTAC rangers in February placed 10 cameras all over the island, thanks to funding from the Gilbert's Potoroo Action Group (GPAG).
Ranger Hayleigh Graham said it would allow most of the island to be monitored.
"It was very hard trekking through there [to set the cameras up]," she said.
GPAG communications coordinator Dr Jackie Courtenay said a series of State Natural Resource Management grants, awarded in 2019, had allowed it to launch a slew of projects designed to preserve the species.
Projects include tracking the genetic variability of different populations, monitoring the fungi and vegetation of their habitat, using radios to track them, and using cameras to monitor feral predators.
Dr Courtenay has been passionate about saving the Gilbert's potoroo since 1996, when she was involved in a state government conservation program.
"It's just the most amazing privilege to be involved most of my adult life to try and help save such a beautiful and critically endangered animal," she said.
Despite the dire situation for WA's Gilbert's potoroo, she said its story so far was motivating because it proved people could make a difference in preserving the species.
"The species would have gone extinct in 2015 with that catastrophic fire at Two Peoples Bay," Dr Courtenay said.
"And it was entirely through good planning [that it didn't].
"Having another safe haven population growing at Middle Island is just so important to make sure if the next fire, God forbid, hits Bald Island, just having animals elsewhere is critical."
