How do you fill in the time while you're up there?

Sydney-based arborist Kalias Wild, 34, said he listens to the birds.

"There's such a variety and they literally go all day," he said. "Coming from the city and listening to chainsaws a lot of the time, it's quite a lovely thing to be able to do."

The tree-sit platforms in the Kalang Headwaters are equipped with solar power for charging devices, so Kai also wields a smartphone and an iPad, sending his photos and words to the wider world.

"There's lots of social media and campaigning to do," he said.

First introduced to this area when he came to help tree portrait artist Steve Pearce photograph a huge blackbutt, Kai is taking time away from his business and is living off savings in order to protest Forestry NSW's plans to log Scotchman and Roses Creek state forests.

Kai said NSW Environment Minister Matt Kean has the power to give these forests and the endangered species that inhabit them the protection they need.

"If he has any ethical standing, he will act immediately before Forestry destroys this critical habitat. The recent bushfires in the region have increased the need for this protection substantially," Kai said.

His fellow aerial blockader Ruby Oliver-King, 28, grew up in Bellingen and has a degree in environmental science specialising in wildlife conservation.

From high in the forest she likes trying to identify the various animals she can hear.

"I've been really interested in the wildlife calls," she said. "I've started recording them and I have a few apps on my phone to check what animals are calling in the forest. And I send it to our ecologists [Mark Graham and Jonas Bellchambers] if I can't figure out what it is."

In a novel twist on teleworking, Ruby also puts in hours as a casual research assistant, tapping away on a laptop entering data into a ecosystems services database.

Unlike Kai, who has done some tree-sitting previously in Tasmania's Tarkine Forest, Ruby is new to the process of putting her body on the line for a cause.

"I am fearful," she said, "and I don't want to be breaking the law and I don't want to be arrested. I don't want a criminal record.

"But I just feel so strongly about this. It's our life support systems that are at stake. So I have to get past that [fear] to protect the waterways.

"I've been involved in non-violent protests but I've never put myself in an arrestable position before."

Ruby said we need to move towards sustainable forestry by creating well managed plantations on old pasture land.

"We cannot afford to lose any more native forest, especially functioning ecosystems such as the Kalang Headwaters, which is a refuge for threatened species and is situated on steep ridge lines with catastrophic erosion impacts for sensitive waterways.

"In a time of drought and water shortages it's ridiculous not to prioritise the health of our water catchments."

Ruby and Kai have been doing shifts of tree-sitting along with a few other people from the protest camp, taking time off during the worst of the Bees Nest fire to help protect Mount Hyland forest retreat.

Instagram post - Ruby Oliver-King August 27

"Day 8 that this huge old growth New England Blackbutt has been occupied in Upper Kalang, in the Bellingen Shire. Lachie and are up here today and it's beautiful; sunshine, mountain views and a cacophony of bird chorus. We are here in support of the Friends of Kalang Headwaters, the community of Kalang and of the Bellingen Shire. We represent the youth who are concerned for our future. We are here to protect the threatened species who are still surviving because of forest such as this. We are calling on the Berejiklian Government to show leadership and immediately end logging of native forest ecosystems. We are calling on Gladys Berejiklian to stop industrial logging in the Kalang Valley and provide sustainable job opportunities for workers. We are calling on Minister Kean to create the Great Koala National Park."

Facebook post - Kai Wild September 21

"It's day 33 of the Kalang tree occupation which we've named the Kalang Forest Rescue Station. Since we started the occupation we've seen 100,000 hectares of native forests burn in neighbouring valleys ... With this sudden loss of so much native forest we have even more reason to fight for these ones to be left alone to both support our threatened native species and to act as vital carbon stores that we so desperately need as the effects of our climate emergency begin to be so clearly felt. Please contact our state Environment Minister Matt Kean who has acknowledged the need to preserve native forests in response to our wildlife extinction crisis and urge him to give these forests the protection they deserve. Please ask a friend to do the same and share this post."

Follow Ruby and Kai on Facebook and Instagram @KalangForestRescueStation