One of Western Australia’s most endangered native birds has had its best breeding season on record thanks to the development of ‘perfect’ artificial nests, say conservationists.
- A record 138 nests have been seen at a conservation site north of Perth
- Breeding success is attributed to artificial nests
- Hollows replicate natural bird breeding habitat
Decades of land clearing in the southwest of the state had put the Carnaby’s black cockatoo in grave danger of extinction, with the disappearance of their traditional breeding ground.
But the researchers found that durable plastic breeding hollows placed high in trees in the area encouraged breeding, and they have the data to prove it.
Rick Dawson studied Carnaby’s in Coomallo Creek Nature Reserve, 200 kilometers north of Perth, for two decades.
There were 41 reported breeding attempts at the outdoor research site in 2009, but last year a record 138 nests were seen.
Mr Dawson said the restoration of nearly 100 decaying natural hollows at Coomallo and the recent addition of 79 new man-made nests were the catalyst for the success.
“They are their worst enemy. When we have wooden cavities, they end up chewing up the sides, chewing up the inside,” he said.
“The purpose of these [artificial nests] is to make them last two Carnaby lifetimes, or about 70 to 75 years.”
“A tree must be at least 150 years old to produce a hollow [naturally] …so the man-made hollows are really a short-term shortcoming until maybe we can keep planting trees.”
Business class comfort for nesting birds
Eva Czislowski, a student at Shenton Park College, has spent the last year leading a school project producing plastic cavities, dubbed “cockatubes”.
The 16-year-old girl and her classmates have made 40 artificial nests which will be distributed throughout the region.
“They are very spacious and they are very attractive to the eyes of birds.
“The goal is to raise a future generation…it’s kind of allowing them a back-up plan.
“If we have young fledglings, it means we are supporting the future…and then nature will do what it wants.
“We just maximize their chances of surviving, living and reproducing.”
Tubes a “short-term” solution
Carnaby’s estimated population ranges between 10,000 and 60,000 over a wide area from Geraldton to Ravensthorpe.
“We found a population that hadn’t been studied before not far from Kalbarri in the Murchison,” Dawson said.
Despite their endangered status, Dawson described them as resilient birds.
“If we can’t save Carnaby’s, we can’t save anything, I believe,” he said.
“They tried so many, many unique food sources. They used to eat bankia on the Swan Coastal Plain, and then we took the bankia out and put in pine trees, and then they immediately adapted to them.
“They are ready to try.”
Last year, Mr Dawson photographed Carnaby’s oldest record, marked with a leg band tied 35 years ago.
“And oddly enough, guess what it was nesting in? A man-made hollow,” he said.
Although Mr Dawson said it was a testament to their ability to survive, helping them reproduce was a nuanced mission.
“The statistics from Perth Zoo are quite clear that the number of injured black cockatoos they receive each year is staggering,” he said.
“We do not want [artificial nests] in the suburbs. Downtown Subiaco wouldn’t be cool.
“We know for a fact that if you don’t put them in a known breeding area, or somewhere there’s enough food, enough water… you can create a hollow and do you good, but that won’t help. nothing. .
Dean Arthurull, who also makes man-made caves and has installed ten at his Bindoon property, said it was a quick fix to a larger problem.
“There is still a huge amount of work to do,” he said.
“We can install artificial tubes in trees and we can do it quite quickly.
“But unless we provide enough natural habitat and foraging habitat for them to breathe every year, then it’s just a stepping stone that doesn’t have a bigger stone after it. You just go land in the water.”