Evolving over millions of years on the once-uninhabited Indian Ocean island best known as the site of the dodo's demise, the green-feathered Echo Parakeet was hit hard by rats, monkeys and the loss of forest that came with the arrival of humans.

But careful breeding, supplementary feeding and the protection of nests have boosted numbers in the wild to more than 320 birds.

It is one of the only good news stories in Wednesday's IUCN Red List -- a list of threatened species compiled by the International Union for the Conservation of Nature and Natural Resources -- which downgraded the species to "Endangered" from "Critically Endangered" in its last report.

"The Echo programme has just been evolving and evolving," said Jason Malham, a New Zealander who has coordinated parakeet work for the Mauritian Wildlife Foundation for seven years.

The non-profit organisation weighs chicks daily for 10 days after hatching and swaps eggs or chicks between mother birds.

"We were looking at maximising the survival chances of every fertile egg," Malham told Reuters.

Dotted about the green, craggy slopes of the Black River Gorges National Park, plastic wrapped around tree trunks protects nest locations and artificial nests from climbing rats.

Workers also help make holes in the trunks deeper to guard against monkeys, which also enjoy parakeet eggs.

The Mauritian project began in the late 1980s and now, with at least 80 percent of the birds tagged, the emphasis is shifting to research and supplementary feeding.

Echo Parakeets savour their favourite food pellets, which come in different colours, shapes, and tastes, Malham said, and throw the others to the forest floor.

While observing their behaviour, conservationists are also keeping a close eye out for a beak and feather disease, which turns plumage yellow and has been fatal for parrots elsewhere.

Deforestation, predators and competition from other birds are likely to remain key threats, experts say, but the Mauritian Wildlife Foundation remains determined to succeed -- pushed by the loss of other local parrots like the broad-billed and grey.