UNITED NATIONS -- Almost a quarter of the world's mammals face extinction within 30 years, a United Nations study on the state of the global environment will announce tomorrow.
Scientists who contributed to the report have identified 11,046 species of plants and animals that are endangered. These include 1,130 mammals -- 24 per cent of the total -- and 12 per cent, or 1,183 species of birds.
The list of the critically endangered ranges from the well-publicised, such as the black rhino and Siberian tiger, to the less well known, such as the Amur leopard of Asia, the short-tailed chinchilla of South America and the Philippine eagle.
Human activities, notably the destruction of habitats and the introduction of alien species from one part of the world into another, are identified as the main cause of this loss in "biodiversity."
The researchers who helped to prepare the Global Environment Outlook-3 (Geo-3) report of the United Nations Environment Programme (Unep) also identify 5,611 species of plants that are facing extinction.
They point out that the true figure is likely to be far higher given that only 4 per cent of the known plant species have been properly evaluated.
The report, which reviews the past 30 years of environmental degradation as well as looking forward to the next 30 years, is understood to say that all the factors that have led to the extinction of species in recent decades continue to operate with "ever- increasing" intensity.
Threats to life on Earth include exploitation of natural resources, pollution, habitat destruction, the introduction of alien species and global climate change, the scientists who advised Unep said.
They believe that the loss of habitats by human encroachment is largely responsible for the predicament facing 89 per cent of threatened birds, 83 per cent of threatened mammals and 91 per cent of endangered plants.