What is happening to the parrot population is most vividly portrayed by Spix's macaw which is as sad a wildlife story as the world has seen in many a day.
Until late last year it was the world's rarest wild bird, with a solitary example of the species struggling on in its native river valley in north-east Brazil.
The blue parrot with the distinctive grey head had been believed extinct until July 1990, when a British ornithologist, Tony Juniper, and a Brazilian colleague found the last individual near the small town of Curaca in the state of Bahia.
All through the 1990s, the wild bird survived by itself while a committee set up by the Brazilian government tried, ultimately without success, to put together a reintroduction programme. About 60 captive birds are kept by private collectors and zoos, in Switzerland, Tenerife, the Philippines and Brazil itself, but persuading them to part with their birds for reintroduction into the wild proved very difficult.
The wild bird was the key, because it alone would be able to teach captive-bred birds essential survival skills where water could be found, which nuts were ripe and how to hide from predators. A major attempt at reintroduction with about half a dozen birds was scheduled for last winter.
But on 5 October last year the wild bird was seen by the scientists monitoring it for the last time. Then it disappeared, and is almost certainly dead perhaps taken by a predator such as a hawk.
"This bird had clung on grimly despite all the odds for a whole decade, and its death is an absolute tragedy," said Mr Juniper, who is writing a book on the Spix's macaw that will be published next year. "The conservationists had 10 years to try to secure this species in the wild, and it certainly raises the question of whether or not more could have been done."Reuse content