New research on endangered species shows that many more bird species than previously thought face extinction.
The findings, published early November in the journal Advanced Science, show that close to 210 forest bird species face an immediate risk of extinction. The study calls for a reclassification of the birds from previous ratings by the International Union for Conservation of Nature (IUCN).
IUCN had classified them as non-threatened in its Red List.
The new study examined 586 bird species, placing the 210 in a higher-threat category. It also found that 189 species should be classified as vulnerable, endangered or critically endangered in the IUCN Red List, that are currently deemed as non-threatened.
The 25-year-old IUCN Red List is the world’s most widely used database of endangered species. It uses various criteria to assess the extinction risk of a species. Species are then classified as threatened, vulnerable, endangered or critically endangered.
“The Red List employs rigorously objective criteria, is transparent and democratic in soliciting comments on species decisions,” study co-author Stuart Pimm and professor of conservation ecology at the US-based Duke University’s Nicholas School of the Environment, Doris Duke said in a statement. “That said, its methods are seriously outdated.”
Part of the criteria the scientists are using to calculate the threat level to a given species is the rate at which its habitat is depleting.
The November 2016 study refined the original ranges for species using geospatial data on the range preferences of the birds, and then added data on the forest cover remaining for the birds, in order to calculate the amount of suitable habitat remaining within their distributions. It was conducted in six of the world’s most biodiverse places — the Atlantic Forest of Brazil, Central America and Western Andes of Colombia, Madagascar, Sumatra and South East Asia.
“Habitat loss and degradation are the biggest threat to most of the species in the world’s most biodiverse places,” says the study report.
The grey-winged cotinga (Tijuca condita), for example, is a bird found in Brazil that is currently listed as vulnerable in the Red List. But its refined range size, according to the study, is smaller than 100 square kilometres, which should shift its threat category to critically endangered. Other species are Marvelous Spatuletatail, Cerulean Paradise Fly-Catcher, Madagascar Fish Eagle and Spix Macaw.
Although the study did not focus on Africa, human activities similar to those in the study areas are common on the continent. They include clearing of wetlands for agriculture and other land uses, deforestation and destruction of habitats.
In 2013, BirdLife International, IUCN’s Red List Authority for birds, added white-winged fluff tail and yellow-breasted bunting to the list of critically endangered species from Africa. Other listed species are the Crested Crane and Shoe Bill, as well as the African Grey Parot.
In May, IUCN and Toyota Motor Corporation (Toyota) announced a five-year partnership to provide funding to broaden the scope of the Red List of Threatened Species.
It is expected that this will significantly increase knowledge on the extinction risk of more than 28,000 species, including many that are key food sources for a significant portion of the global population.