Contractors had been due to chop down the tree this morning but left saying they did not have the power to remove protesters.
One protester, Michael Tavares, climbed 25m up the tree and told Radio New Zealand he was "prepared to spend some time up here".
He said he heard about the issue on Twitter, and contacted the campaign organisers to find out more. When he learned the trees were to be felled this morning, he came to lend a hand. "I'm up here and I'm safe, I'm securely on," he said. "I'm safe up here so long as work isn't attempted to fell this or other trees near it."
"I'm under no illusions that the tree is saved, or that me up here is going to solve all the problems, but it does mean the tree stays another day so the conversation can keep happening. I'm prepared to spend some time up here, but I can't reveal too much about my strategy."
Tree experts estimate the kauri has been alive since the 1500s. Another tree estimated to be about 300 years old has also been targeted for felling.
Community spokeswoman Aprilanne Bonar helped to launch a "Save Our Kauri" Facebook page in a bid to raise awareness.
The page has more than 800 supporters and has attracted hundreds of comments from unhappy members of the public.
"We're trying to be the gatekeepers," Ms Bonar said yesterday. "If we can save this tree, it really sends a strong message that there needs to be a balance in any type of development."
She said locals were shocked when it was revealed Auckland Council had granted the developers of the site resource consent to build on the land.
The council's west resources consents manager, David Oakhill, said two separate consents had been granted for two houses to be built on the site - which meant the removal of some trees.
A number of trees were removed on Friday.
As part of assessing the resource application, the council said it considered the effects of the tree removal, the ecological value of the sites and the effects of the development itself.
As a result, they were satisfied that all appropriate measures had been taken to minimise those effects.
"In fact, the developers have elected to build the houses close to the road which minimises the number of trees that need to be removed because there will be no long driveways," Mr Oakhill said.
"Auckland Council understands people's desire to protect our natural environment, however the zoning on these two sites recognises the right to build while taking the environment into consideration."
The owner and developer of the site, John Lenihan, declined to comment last night.
Mr Lenihan is listed on LinkedIn as the company director of the Retail Construction Group Ltd, based in Parnell.
Ms Bonar said the protesters were not against developers building in the area, but wanted them to consider designs that might save historic aspects of the region.
"It scares me. In 10 years' time, we'll be looking at another Remuera ... there's nobody out there protecting the environment."