As a senior biodiversity officer with the Department of Environment, Land, Water and Planning (DELWP), his mission is to preserve the unique bird.

"It's been a 21-year project looking at and understanding the cockatoo, how rare it is and what the causes of their decline are," Mr Hill said.

"My aim is to stop it from going extinct.

"This area has a really small population of about 1500 and it's in decline. It's quite endangered in small parts of south-west Victoria and South Australia.

"They're a very unique sub-species only found in this small part of south-west Victoria."

He is part of a larger recovery team for the cockatoo.

"There are lots of people working trying to help the cockatoo. DELWP and what I do is a small part of that," he said.

A major part of his work here is helping with the annual count, organised by Birdlife Australia, where willing and able volunteers head out in fleets of vehicles to track the birds and monitor their population numbers.

"The count involves up to 80 vehicles and is all done by volunteers. I've been doing that for 21 years," he said.

"We try and find where the birds are and how many there are, that produces a ballpark figure - it's not completely accurate because it's very hard to count them in flocks.

"The detailed counts happen as they come into the drinking sites. That involves sitting close by with binoculars and cameras.

"It takes multiple days and evenings to find where they are drinking, it's a bit of a process to set up, liaise with who owns the land and get permission to go on if it is private land.

"That can happen over 20 nights but it's the best information we have."

He said the red-tailed black cockatoos were disappearing at high rates.

"The bird is in decline, and now we're trying to find out why," he said.

"The rate of decline has steepened in the last five years and we really need to work out if there's something new we have missed.

"We understand their food sources are declining and we are planting lots of trees to arrest that decline.

"There might be other things affecting the birds, so we are about to launch new studies into what causes breeding success and how to help them in the wild."

Mr Hill suspects climate change is a large contributing factor to the decline of the species.

"Climate change really is the elephant in the room for this species because it depends on the eucalyptus trees," he said.

"They get seeds of a couple of species of eucalypt and their flowering appears to be linked with rainfall.

"Climate change may be causing them to produce less feed, we have to try and diagnose it because they are critical resources.

"We need to look at the ecology and find out what's going on."

Birds have always been Mr Hill's passion.

"Birds are my thing, I did my masters on owls on Christmas Island and I've been studying birds for most of my working life," he said.

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Mr Hill and his team are looking for volunteers for the next annual count.

"The annual count takes place at the start of May and we're always looking for people to help with that," he said.

"We're also looking for private properties to plant more trees for the birds to feed and nest."

Those interested are asked to contact the Birdlife coordinator on 1800 262 062.

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