Jiritju Fourmile remembers when extreme heat wiped out colonies of bats on his traditional country of Gimuy in Far North Queensland.

During a Queensland Land Court site visit regarding a proposed coal mine in the Galilee Basin, he aired his concern climate change from fossil fuel extraction would lead to the horror being repeated.

The Gimuy Walubara man from the Yidinji Nation took the court to a site in Cairns' southern suburbs where a 2018 heatwave killed an estimated 23,000 spectacled flying foxes, about a third of the endangered species' population.

"When we lose the bats through this area, that's all our pollination gone for our plants," Mr Fourmile said.

"They're our farmers. If we don't do something to protect them, what's going to happen to all our native species?

Youth challenge mine

Mr Fourmile gave evidence on Gimuy in a case between Youth Verdict, a group of young Queenslanders, and Clive Palmer-linked Waratah Coal, which is proposing to develop the coal mine.

The youth coalition is challenging the mine, arguing the resultant greenhouse emissions would violate human rights and Indigenous cultural rights.

Proponents of the case hope the mine will be blocked from going ahead, but they also want First Nations' rights to be considered in future approval processes.

Last week, the case heard evidence on Erub Island and Poruma Island in the Torres Strait, Queensland's first-ever on country testimony in a mining lease objection hearing.

'Can't say we don't know'

In his testimony to the court on Tuesday, Mr Fourmile cited the mass bat deaths as evidence of the devastation climate change was causing and its effect on the Wet Tropics environment.

He noted the spectacled flying fox is a keystone species that helps to pollinate rainforests and is critical to the region's biodiversity.

Murrawah Johnson, a Wangan and Jagalingou woman, said country was inextricably linked with the cultural identities of traditional owners.

The Galilee Basin mine is proposed to be built on her country in central Queensland.

She said First Nations people "have an obligation to be involved in the decision making".

"We're in a time now where we can't say the approval of mega coal mines, whether it was in the Bowen Basin 20 years ago or whether it's in the Galilee Basin today ... don't have impacts on people elsewhere," Ms Johnson said.

"Unfortunately, legislation and practice like native title really limit the ability for First Nations people to make decisions about on country direct developments and mining approvals."