The red boundary on the map scoops up the city’s jawline from Kurnell, travelling along the throat of the Georges River, before turning south with the river down the back of the green neck that is the Heathcote National Park.
The park holds part of the Woronora Dam and is flanked either side by Holsworthy Army Base and the Lucas Heights reactor.
Tucked away among the roll of hills, it is also prime koala real estate, discovered by two bushwalkers.
“The very first tree we looked in had a koala in it,” says Steve Anyon-Smith, lockdown bushwalker turned citizen scientist.
“We started finding two or three, and then four or five, and we didn’t realise at the time ‘how are we going to keep track of whether we’ve seen the same animal?'”
So Steve and fellow koala spotter Tim Kristensen began taking photos of each new koala discovered, advised to capture each nose as a koala ID.
Steve references his computer file of photos, each animal lovingly named on a screen full of folders. He opens one specifically.
“We can see that the pink on the inner nostril, where it meets the darker part of the nose of the koala, is not a straight line,” he says.
“And that differs from koala to koala?” I hypothesise.
“Absolutely,” Steve says.
The citizen scientists have also captured rare bush moments in moving vision, such as mum Patsy feeding her joey Mel.
There was the big milk-drunk yawn by another baby at meal’s end, and the moment a brown-headed honeyeater was pecking at the fur of a koala named Anita, snatching it in clumps to build her nest.
Their research has revealed nearly 80 previously undiscovered individuals, reaching as close to suburbia as Woronora and Menai.
It’s believed the crown land of the Holsworthy Army base and the Woronora Dam catchment have acted as a koala nursery.
“I think if you keep away dogs and cars, and you don’t set fire to them, koalas are quite capable of living nearby,” Steve adds, as he scrolls through the shots of koalas lolling in the forks and stretched across the limbs of grey gums.