Dr Denis Saunders returns to Coomallo Creek

Dr Denis Daunders holds a female Carnaby's black cockatoo chick. Picture: Katherine Howard.

On a baking hot November day WWF-Australia President Dr Denis Saunders returned to Coomallo Creek, Western Australia, where more than 30 years ago he first started investigating the dramatic decline of Carnaby’s black cockatoos.
Coomallo Creek is a known Important Bird Area for Carnaby’s black cockatoos. It is about three hours north of Perth in the global biodiversity hotspot of Southwest Australia. Katherine Howard accompanied the team which included senior DEC staff member Rick Dawson and sent back this report.

The air conditioner barely had time to kick in and provide some blissful relief from the baking heat outside when the 4WD in front of us braked and both vehicles came to a sudden stop. Rick and Denis quickly piled out.

They had spotted an adult Carnaby’s black cockatoo emerging from a tree – which meant they’d found a previously unrecorded nest hollow, not three metres from the well-travelled farm track and less than five minutes drive from the homestead.

Carnaby’s black cockatoos have been nesting in Coomallo Creek for at least the past four decades, and probably hundreds of years before that.

Dr Denis Saunders AM, President of WWF-Australia, member of the Wentworth Group of Concerned Scientists and former Chief Scientist of CSIRO, knows (almost!) every hollow tree on this property. It’s possible he knows the bush even better than the owners – after all, he started studying the population of Carnaby’s cockatoos that nest here back in 1969, when the current farmer was just a babe in arms.

In those days, white-tailed black cockatoos were considered pests by the fruit growing and pine industries and there was even a bounty on their beaks.

This deliberate persecution, along with extensive removal of habitat, competition from feral bees, invasive galahs and corellas, road strikes and a certain amount of illegal smuggling, have all contributed to the total population of Carnaby’s black cockatoos crashing by more than 50% in just 45 years.

There have been many regional extinctions and the species has disappeared from over a third of its former range. However, the main reason for this dramatic decline is land clearing. Most vegetation in their spring breeding habitat of the wheatbelt has already gone. Thanks to the urban sprawl of Perth and other coastal settlements, now they are rapidly losing the coastal feeding and roosting trees they rely on during the non-breeding season as well.

Denis monitored the Carnaby’s cockatoos nesting at Coomallo Creek at various intervals from the late sixties to 1996. This year, the WA Department of Environment and Conservation (DEC) generously supported two trips to the site, using the same monitoring protocols used in previous years, to check on the number of nesting hollows available today and more importantly, the number of Carnaby’s cockatoos using them.

Thanks to a combination of modern technology and Denis’ hand-marked maps, they were able to locate every hollow tree that Denis had recorded decades ago.

The Carnaby's black cockatoo team band a chick and take its vital statistics. Photo: Katherine Howard.

Sadly, many of the hollow trees had been cleared, collapsed or burnt in the intervening years.

The concern is that in many parts of the wheatbelt there are almost no young trees coming up to replace those that are lost. This landholder has given his patch of bush the best chance of regeneration by fencing it off from his sheep, but it takes anywhere from 120 to 250 years for a tree to form hollows large enough for Carnaby’s cockatoos. For that reason it is important to ensure that there is regeneration of young trees to supply the nest hollows of the future.

But it wasn’t all bad news at this site. The team found 41 active nest hollows, up from only 32 in 1994, but still nowhere near the top known figure of 88 active hollows recorded in 1975.

Denis and the researchers from DEC were cautiously optimistic about this increase.

“This site is an ideal situation for Carnaby’s black cockatoos – you’ve got water here, you’ve got food close by and you’ve got plenty of available nest hollows,” explained Denis.

“But what we’re perceiving as a slight increase in nesting birds here does not necessarily translate across the whole population. These birds, for example, we know are not the ones that we see in Perth; these individuals move between Beermullah and the Arrowsmith River in the non-breeding season. So these are not the individuals who are currently coming under most pressure from urban development as we speak.”

Assisting Denis in the field were Peter Mawson and Rick Dawson, senior staff from DEC; Mark Blythman, also of DEC, working on feral bee control; and Raana Scott, Project Manager for the Carnaby’s Black Cockatoo Recovery Project

The Carnaby cockatoo project is a partnership between Birds Australia, WWF-Australia and other groups and is funded by multiple Natural Resource Management bodies and the Australian Government’s Caring for our Country program.

The team took weight and wing measurements, which can be used to calculate the age of the chicks. Most chicks appeared to be in good health. DNA samples were taken and all chicks were ‘banded’ – that is, a metal ring was fastened around their legs for future identification.

Thanks to the band technique, which has been in use for centuries, Denis was able to identify some of the mother birds as those that he had banded up to 25 years ago. This gives us an idea of the likely life span for this species – we know that some birds are still breeding at 25 years old.

The plight of Carnaby’s cockatoos has been attracting considerable media interest in recent years so we invited the new Environment Reporter for the West Australian newspaper, Michael Bennett and his photographer, John Mokrzycki, out to the site.

We also invited Rob Carroll, former Chief Financial Officer of Woodside Petroleum, member of numerous Boards, keen eco-traveller, wildlife enthusiast and long-term valued supporter of WWF, to come along and see WWF and partners in action in the field.

Acclaimed filmmaker Leighton de Barros was out with the team most of the week, collecting footage for his next documentary which focuses on black cockatoos in Southwest WA.

Despite the heat and hordes of very persistent flies, I think Rob and the journos enjoyed meeting the research team and finding some healthy young Carnaby’s cockatoo chicks – well I know I certainly did! Rob dropped us a lovely email afterwards to show his appreciation.

Rob Caroll gained some hands on experience of Carnaby's conservation on his trip to Coomallo Creek. Photo: Katherine Howard.

“Dear Katherine,

Thank you so much for hosting me for a great day’s experience which gave me an insight into the Carnaby’s Cockatoo recovery project. It was exciting and gratifying to see that there were numerous healthy chicks at the Coomallo Creek breeding site north of Badgingarra in the wheatbelt. This new generation provides hope for the future of the species.

I was impressed with the professionalism and dedication of the team undertaking the mapping and recording of the nest sites and banding of the Carnaby chicks. The enthusiasm shown for this project by your President, Denis Saunders was apparent, particularly since he first kicked off the research in 1969! It was also good to see the strong support you received from the WA Department of Environment and Conservation through the contributions of experienced senior staff such as Peter Mawson and Rick Dawson.

Please send my thanks to Raana Scott and her team.

Regards,

Robert Carroll”

For more information on Carnaby’s black cockatoos, including a copy of Dr Denis Saunders’ PhD thesis “The Biology of the Short-Billed Form of the White-Tailed Black Cockatoo, Calyptorhynchus funereus latirostris Carnaby, 1967” click here.