Tying a piece of brightly coloured marker tape to a scraggly-looking tree, Kamahl Bangu says something unexpected.

"My dream came true."

It has been days, and most of the conversation up until now has centred around football, how annoying the flies are and what work needs to be done.

But that's the thing with being on country, in the bush. You share a little bit more with your camp mates than you would if you were in town.

"My grandfather was a head ranger before he passed away."

The quiet of the desert between his words gives them weight.

"I used to go out with them when I was more small," Bangu continues.

"And I always wanted to be a ranger, so yeah, here I am out in the field."

He smiles as he walks back towards the 4WD, out here in the Great Sandy Desert of Western Australia.

Bangu is a Karajarri Indigenous ranger, a success story from the school-based trainee program, and is close to receiving his Certificate III and becoming a senior ranger.

Along with all of the other rangers on this trip, Bangu lives in Bidyadanga on the coast about 200 kilometres south of Broome, but the area that they're tasked with looking after is vast.

Traplines like this help rangers study what species live in the area. ( ABC Science: Ann Jones )

Karajarri country is mind-bogglingly huge. It stretches from the turquoise waters and white sands of the Indian Ocean coastline, where sea turtles nest and dugongs glide over seagrass beds, to the Great Sandy Desert, where bilbies nip in and out of burrows, and sand sliders — skink-like lizards with fairly useless legs — dominate the dunes.

The Karajarri Indigenous Protected Area covers some 32,000 square kilometres, but no major river flows through it. In the desert there are a series of soaks and water spots hidden among the dry, which require regular maintenance to keep clear — work often undertaken by the rangers.

Kamahl Bangu sets up a camera trap. ( ABC Science: Ann Jones )

There's a Karajarri saying: "palanapayana tukjana ngurra". It means "everybody looking after country properly".

Watching Bangu work is watching these words come to life.

He's observant, purposeful, respectful and, above all, he has the presence of a young man who is home.

Bangu is preparing to speak at one of the biggest environmental science conferences in Australia: the Ecological Society of Australia conference in Launceston in November.

"I think I'm going to take, like, 10 jumpers and wear them all," he says, brushing flies away from his face.

But don't be fooled by the flippant answer — Aboriginal leaders like Bangu are the future of Australia's conservation, even if acknowledging this in a conference centre in Launceston feels a world away from the work on the ground.

Ranger schemes in the Federal Government's Working on Country program employ more than 830 full-time rangers, and land held under Indigenous tenure makes up half of Australia's terrestrial area.

Karajarri country is vast. ( Threatened Species Recovery Hub: Nicolas Rakatopare )

Here, in a place called Kulgara within the protected area, it's dry and hot. So hot that, over the course of the week in the desert, no less than three pairs of shoes in the group bite the dust, soles detached from uppers in the 45 degree-plus radiant heat.

Gaffer tape is deployed, and the rangers complete their first major task for the week: installing 800 metres of trap lines and digging 80 pit traps for a scientific survey of the small fauna of the desert.

Pit traps capture small fauna for study. ( ABC Science: Ann Jones )

A short fence is partially buried with buckets submerged along its length. Small animals meet the fence as they're going about their daily activities.

They run along the fence and fall into the bucket where they are unable to get out. The traps need to be checked constantly so that the animals don't over-heat or get eaten by another animal at the bottom of the trap, so even after the digging, the graft is relentless.

This work is an act of love for country.

Karajarri Indigenous ranger Marissa Munroe. ( ABC Science: Ann Jones )

Old traditions, new techniques

The rangers don't just want to know what's still there in the desert, but also what sort of impact fire has on the biodiversity.

"The Karajarri are very invested in managing fire," says Sarah Legge, an ecologist from the Threatened Species Recovery Hub who is collaborating with the rangers and helping with the technicalities of setting up scientific monitoring on the IPA.

"As part of that management, they want to be able to see how fire management is changing their Indigenous Protected Area, and they want to be able to demonstrate that to other people," Professor Legge says.

Representatives from the Ngurrara Indigenous rangers work on Karajarri country. ( ABC Science: Ann Jones )

The rangers keep meticulous notes of the species they find. ( ABC Science: Ann Jones )

"The old people, they used to do the old ways of burning, and we get to do the aerial burning," says Jacqueline Shovellor, a senior cultural ranger with the Karajarri rangers.

"And the old people don't understand that — they say 'we don't like that aerial burning'."

The helicopters move quickly over the landscape in the burning season, at lighting pace compared to on foot.

But the fire that drips from the rangers' sticks aims to recreate the millennia-old burns of pre-colonisation Karajarri, who selectively burnt as they walked over their country.

Marissa Munroe (right) with fellow Karajarri ranger Jacka. ( ABC Science: Ann Jones )

"It's good for old people to learn, to see what the rangers do on country with burning. Maybe they'll get a better idea of how it's done [now]," Shovellor says.

The intention is to create a patchwork quilt of different vegetation types, created over the course of decades, providing different habitat types for plants and animals to flourish. Exactly which species, where and when is what this scientific program is trying to quantify.

Leopard Ctenotus are still found on Karajarri country, but many other species are missing. ( ABC Science: Ann Jones )

Learning from each other

Other ranger groups are looking to the monitoring program that the Karajarri rangers have set up to learn from and potentially apply in their own jurisdictions.

The visitors, which include Elton Smiler, a senior ranger with the Ngurrara Indigenous rangers, provide extra hands on deck for the busy field weeks when the data gathering is underway.

Senior ranger Elton Smiler and his fellow Ngurrara rangers visit Karajarri to help with fieldwork and share knowledge. ( ABC Science: Ann Jones )

The land the Ngurrara rangers look after is further inland into the Great Sandy Desert and encompasses some of the Canning stock route in its almost 78,000 square kilometres of exclusive possession native title.

"I like to work with different ranger groups and share different knowledge and I like to go out country, go out bush — it builds my confidence up and my strength," Smiler says.

"I learn something new every time we go out into the field and work with researchers, it's a different experience for me."

Chantelle Murray leans forward to examine a specimen. ( ABC Science: Ann Jones )

Pride is something that dominates Raylene Lenmardi's experience as a Ngurrara ranger.

"I really enjoy working and waking up every morning. Putting on the uniform makes me proud of who I'm working for," Lenmardi says.

"I would like to see more young women join in the ranger program for future generations, so they won't lose their culture and knowledge and also, so they won't lose their connection to country."

Later, the rangers spread out, searching for plants that might be used as food or medicine, under Shovellor's instruction.

Senior ranger Jacqueline Shovellor says she's alive today because of bush medicine. ( ABC Science: Ann Jones )

"When we were small we used to go out on country with our old people, coming out in the school holidays and they taught us about plants, because some bush tucker has a story," she says, pointing to a tree with a thick crown of greyish leaves.

"My grandmother had a bad whooping cough, and she was small then, and her mother and father couldn't get anyone to fix it [in town].

"So they took her to the desert, way up in the desert to look for the bush doctor man and they helped her.

A hand holds a gardenia fruit. ( Threatened Species Recovery Hub: Nicolas Rakatopare )

"On the way she had some of the supplejack tree — they boiled that up and she drank that and she got better from it.

"I think about that story all the time. Because if she would have got really sick... I wouldn't be here telling the story, you know?

"So, when we go out for bush medicine, we talk about the plant and tell stories for it before we collect it."

But, as we walk in a line across the landscape, there's not much in flower. Shovellor's worried — there doesn't seem to be much food around.

"On our seasonal calendar, we look at the months when we are supposed to be collecting our fruits," she says.

"The climate change has really changed it — sometimes you don't find [the food] at the right season.

"Sometimes, you don't find it at all."

The delicate mouse is a small native rodent. ( ABC Science: Ann Jones )

A large scorpion. ( ABC Science: Ann Jones )

The monitoring program marries traditional knowledge and observations like Shovellor's with western scientific approaches and will be used by the rangers to inform their management of their country in the future.

Even preliminary results from the two rounds of scientific monitoring the rangers have completed so far tell a very stark story.

A gecko captured on Karajarri country. ( ABC Science: Ann Jones )

Mammals that used to live on Karajarri country have been rendered regionally or even globally extinct, like the spectacled hare-wallaby, the woylie or the red-tailed phascogale, and the animals found in the traps so far have nowhere near the diversity that might be expected.

"If conservation is your game, then this is your future," Professor Legge says.

"A key reason for a scientist to work with Aboriginal people in Australia is to try to see the country through their eyes — makes you a better ecologist as well as a richer person."

Close to half of the National Reserve System is within Indigenous Protected Areas. Of all of Australia's current known threatened species, three-quarters of those species occur in Indigenous tenures.

When it comes to the extinction crisis, Aboriginal leaders like these rangers bear a weight of decision making on a scale that well outstrips their responsibility for it.

Karajarri ranger Vanessa Kitty enjoys a moment of reflection at sunset. ( ABC Science: Ann Jones )

On the flip side, the power that they have — to so profoundly impact the future of Australia's natural assets — is also a step towards reconciliation.

"When I'm out on country I just feel free," Shovellor says.

"You got no worries out here and [when you're] doing things out on country, your mind takes the all the stress away."