Early on he noticed that growers used a gel to add hormones to their kiwifruit vines. With help he adapted a herbicide gel that's applied to the cut stems and trunks of weed species.
Previously DoC workers cut the stems of weeds like old man's beard, and returned later to spray regrowth. Cutting and gelling killed the plant down to its roots, doing both jobs at once.
Herbicide gels, usually with glyphosate as the active ingredient, are now in common use.
Since the early 1990s Whanganui's inland forest has had aerial 1080 applications to kill possums. People noticed that stoat numbers reduced after each operation, and Fleury promoted the three-yearly treatment regime that now protects kiwi in those forests by killing stoats as well.
The operations allow enough young kiwi to survive to replace those who die. If their habitat is maintained and dogs are controlled the operations could ensure the survival of our national bird.
The technique has been adapted to control outbreaks of rats and stoats in South Island beech forests, in DoC's Tiakina Ngā Manu/Battle for Our Birds initiative.
"The learnings from Whanganui have been taken forward into big operations in the South Island and parts of the North Island. Now, it's a very professional operation," he said.
By 1996 the protected wild horse herd in the Kaimanawa area had built up to the point that horses were nearly starving. Fleury had to put a plan in place that was acceptable to both conservationists and animal lovers.
The first big horse muster was in 1996, and for three years it sparked more letters to the Conservation Minister than any other issue.
It was " touch and go" at times, but the annual musters continued.
They have become a routine event, supported by all parties.
"It's become a real success story, keeping a population at a low density that's sustainable for the landscape and the other uses of the area," Fleury said.
Most recently, with climate change gaining prominence and native forests collapsing under pressure from possums, goats and deer, he asked whether conservation land could be better managed to store carbon.
That gained a lot of interest, especially from Forest & Bird, and is now being consulted on by Government. If it gains some traction and is paired with Predator Free New Zealand, It could make a big difference to the country's carbon budget.
"Then we get two outcomes for the price of one."
Fleury studied analytical chemistry at university and fell into conservation work by chance. He took two summer jobs with the Forest Service because he liked tramping and they felt like "being paid to go tramping".
After DoC's Whanganui office became a district one in 2012, he commuted to work in the Palmerston North office. Since retirement he's remained active on the Bushy Park advisory group and in the blue duck protection programme, and with the Friends of Gordon Park.
