Life on  Earth is disappearing fast, with one in four mammals and one third of all amphibians in jeopardy, according to an annual survey published on Wednesday.
Conservation measures have  had only a limited impact, according to the results of the World Conservation Union (IUCN).
The Red List of Threatened Species compiled by the IUCN now includes 41,415 species. Of them,  16,306 are threatened with extinction, an increase of 88 from the previous year.
One in eight bird species and 70 per cent of the world’s assessed plants are also at risk.
“The rate of biodiversity loss is increasing. We need to act now to significantly reduce it and stave off this global extinction crisis,” IUCN Director General Julia Marton-Lefevre said.
The great ape, one of man's closest relatives, has shifted from endangered to critically endangered status.
This came about with the discovery that two thirds of the Western lowland gorilla had been wiped out by the commercial bush meat trade in the past 20-25 years and by the ebola virus.
More species on list
The Yangtze river dolphin has been listed as critically endangered (possibly extinct), though further surveys are needed before it could be reclassified as extinct.
The Sumatran orangutan remains in the critically endangered category, while the Bornean orangutan is in the endangered category, due to loss of habitat through illegal and legal logging. The Gharial crocodile found in India and Nepal has also moved from endangered to critically endangered list.
The population declined  by 58 per cent-from 436 breeding adults in 1997 to 182 in 2006, due to damaging irrigation projects.
Nearly 10,000 birds appear on the list, with 1,217 listed as threatened. Vultures in Africa and Asia have declined with five species reclassified.
More than 12,000 plants are included, with 8,447 listed as threatened.
According to the survey, only one species has moved to a lower category of threat.
The Mauritius echo parakeet has shifted from critically endangered to endangered as a result of conservation action.
“This one achievement was a disappointing tally for conservationists,” said Jean-Christopher Vié of IUCN’s species programme.
“This is really worrying in light of government commitments around the world, such as the 2010 target to slow down biodiversity loss,” he said.
Precise status
Jane Smart, Head of IUCN's Species Programme, said: “We need to know the precise status of species in order to take the appropriate action. The Red List does this by measuring the overall status of biodiversity, the rate at which it is being lost and the causes of decline”.
“Our lives are inextricably linked with biodiversity and ultimately its protection is essential for our very survival. As the world begins to respond to the current crisis of biodiversity loss, the information from the Red List is needed to design and implement effective conservation strategies - for the benefit of people and nature.”