WILTING leaves and auburn foliage is lining the once green North and Middle Brother Mountains, in a disconcerting display of the bush's struggle against the dry.
But the definitive cause behind the changing Camden Haven forest landscape remains unknown.
Long-time residents have been baffled by the phenomena, which has, in as little as four weeks, instilled an almost eerie feel to the familiar backdrop.
Among them, is Lake Cathie photographer and blogger Brett Dolsen.
Mr Dolsen has been documenting the distinct browning and dieback of the once flourishing canopy for the past few weeks.
The foreign foliage colour on North Brother, Middle Brother and South Brother mountains, he believes, is cause for concern.
"While some of this change can be expected from the prolific flowering of Eucalyptus trees this year, closer inspection reveals that many trees are dying or suffering extreme browning and loss of foliage," Mr Dolsen said.
In many parts of the mountains, a once vibrant sea of green has been replaced by suffering plants, stony surfaces and dying scrub.
He said the current situation, again puts into question the impact climate change could be having on local ecosystems.
"It concerns me, because it's basically starting to look like a bare mountain top," said Mr Dolsen, who has never seen anything like the prolific drying on Middle Brother mountain in more than three decades of living in the Hastings. "It would be fair to say the mountain has dried up."
Area manager for the Manning Hastings National Parks and Wildlife Service Steve Atkins said at this stage, there was no definite explanation for the situation.
He did point to studies, however, exploring the relationship between dry weather and heat-induced forest dieback and mortality.
"A relatively shallow soil profile and extreme heat conditions is thought to predispose water shedding sites such as mountains and sloping hillsides - to drought triggered canopy dieback during extended periods of dryness," Mr Atkins said.
Other than visual observations, he said there had been no research into the situation on the local forest landscape.
Conditions in the nearby Werrikimbee National Park have been found to be the driest in 60 years, Mr Atkins said.
These dry conditions have been causing bushfires to burn through areas that would previously have been wet enough to halt its progress.
Mr Atkins said he would expect significant rainfall to result in a recovery for the forests on the Brother Mountains.
How long this process would take, however, could be anyone's guess.
"I would also expect that with the canopy dieback that there may also be an impact on native wildlife in the area at least for the short term," Mr Atkins said.
Among other possible causes for the browning, NSW National Parks staff have suggested the following:
* Bell Miner Associated Dieback.
* Localised fires with canopy die off as a result.
* Severe dry conditions, especially given that these areas are on very shallow, rocky soils.