The Alaotra grebe, Tachybaptus rufolavatus, also called the rusty grebe, had been highly vulnerable as it was found only in Lake Alaotra, eastern Madagascar, said the Swiss-based International Union for Conservation of Nature, which compiles the famous Red List of endangered species.

The grebe was wiped out by habitat destruction, by the introduction of a carnivorous fish called the snakehead murrel and by nylon gill-nets which accidentally caught and drowned many birds.

"No hope now remains for this species. It is another example of how human actions can have unforeseen consequences," said Leon Bennun, director of science at BirdLife International.

BirdLife contributes data to the IUCN's Red List on the world's 10,027 recognised bird species.

Of these, 132 species are now extinct; four are extinct in the wild; 190 are critically endangered; 372 endangered and 838 near-threatened.

Of the remainder, 7,751 species are categorised as being of "least concern" while data is insufficient to judge the status of 62. The IUCN sounded the alarm for wetland birds, imperilled by the draining of marshlands and by alien species that are introduced for food.

"Invasive alien species have caused extinctions around the globe and remain one of the major threats to birds and other biodiversity," Mr Bennun said.