SYDNEY, March 29 (Xinhua) -- A team of biologists have assembled the genetic sequences of one of Australia's most iconic native birds, the helmeted honeyeater, in a bid to restore their numbers.
The findings, published in the GigaScience journal on Tuesday, have for the first time created a high-quality mapping of the honeyeater's genomic sequence which will allow conservationists to increase the "genetic health" of the endangered bird.
"The genome sequence and the genetic map will be used to get the right balance between rescuing the helmeted honeyeater from extinction through inbreeding, while retaining its unique features," said lead author Dr. Diana Robledo-Ruiz of Monash University.
Populations of the helmeted honeyeater, which appear on the emblem of the state of Victoria, as that region's only endemic bird, have vastly declined in the 200 years since Australia was colonized by Europeans.
By the 1980s only 50 of the birds were known to remain in the wild, all in Yellingbo Nature Conservation Reserve in Victoria.
Now the populations have been restored to around 250, however, due to high levels of inbreeding, they lack genetic variation to sustain a healthy population.
Professor Paul Sunnucks, head of Monash's Persistence and Adaptation Research Group, told Xinhua that this inbreeding could drastically reduce their ability to reproduce.
"It makes it difficult (to conserve the species), it means that you're really pushing uphill all the time," he said.
The gene rescue project, which has been heavily informed by the genomic sequence, will seek to diversify the bird population by interbreeding them with closely related yellow-tufted honeyeaters.
"The only way to get any sort of fresh blood as it were, any new genes, was to cross them with the most appropriate other population," said Sunnucks.
This process of "genetic rescue" has garnered some controversy in the scientific community as it can be difficult to predict the outcomes.
Sunnucks said this risk, however, was far outweighed by the "very great risk of not doing something."
"We demonstrated that they were extremely likely to go extinct relatively soon, through inbreeding problems and other genetic problems... that should really change your perception of risk."
Sunnucks said the ultimate goal was to establish five habitats of about 100 helmeted honeyeaters within the next five to 10 years.
"It wasn't all that long ago that Yellingbo Nature Conservation Reserve, which at the time was the only place with helmeted honeyeater in the entire world, was threatened by fire. And if the wind had been a bit different... we could have lost a lot in one day." ■