Nearly 200 animals and plants have been added to a global database of threatened species, the World Conservation Union announced Wednesday, adding that the number is certainly on the low end.
From the lowland gorillas of Africa to corals of the Galapagos Islands, more than 16,300 species are threatened with extinction, the group said in releasing its annual Red List.
"The rate of biodiversity loss is increasing, and we need to act now to significantly reduce it and stave off this global extinction crisis," Julia Marton-Lefèvre, the group's director general, said in a statement.
The group noted that while extinctions are a part of nature, its findings show that humans are accelerating some extinctions. "Estimates vary greatly, but current extinction rates are at least 100-1,000 times higher than natural background rates," it said in a statement.
In what is billed as the world’s most authoritative assessment of Earth’s plants and animals, the group considered 41,415 species and found that of those, 16,306 were under threat, said Craig Hilton-Tailor, the list’s manager.
That is 188 more species than last year. Even so, Hilton-Tailor said, there are probably many more than that.
'Tip of the iceberg'
“The estimate is low; we know it’s low,” he said. “We’ve only really looked at the tip of the iceberg in terms of species that are out there that are known to science.”
The total number of extinct species has reached 785 and a further 65 are only found in captivity or in cultivation, the group, also known by the acronym IUCN, said in its statement.
One in four mammals, one in eight birds, one third of all amphibians and 70 percent of the world’s assessed plants on the 2007 Red List are in jeopardy, the IUCN added.
While it does not play a major role in U.S. decisions on wildlife conservation because the United States does this through its own Endangered Species Act, the IUCN is highly influential in other regions, particularly in developing countries that cannot afford to make their own assessments of which species are in trouble.
Its members includes nations, government agencies, non-governmental organizations and thousands of scientists.
The IUCN noted that while the total number of species on the planet is unknown, estimates vary between 10 million and 100 million — with 15 million species being the most widely accepted figure. Nearly 1.8 million species are known to exist.
Corals and warming seas
For the first time, corals were added to the list due to threats that include the warm-water Pacific Ocean pattern El Nino and global warming.
"The fact that corals are now present on the IUCN's Red List should sound warning bells to the world that the oceans are in trouble," said Simon Cripps, director of the global marine program at the World Wildlife Fund, an IUCN partner.
Hilton-Tailor said global warming is a factor in these and other species’ endangerment, but not the only factor.
“It’s really hard to identify whether it’s climate change or not that’s driving some of these species to extinction,” he said. “Climate change doesn’t operate by itself, it’s operating in tandem with other threats and it’s usually the combination of climate change and possibly the threat of a new disease ... it’s different combinations that can push species over the brink.”
The Galapagos Islands saw 10 native coral added to the list, as well as 74 seaweed species.
Besides being affected by warmer water, the seaweeds are also indirectly affected by overfishing, which removes predators from the food chain and results in an increase of sea urchins and other herbivores that overgraze seaweed beds.
Ebola wiping out gorillas
Asked to name a particularly troubling example of an endangered species, Hilton-Tailor mentioned the western lowland gorilla, which moves from endangered to critically endangered on the latest list. Its decline is due to the Ebola virus and commercial hunting of so-called bush meat.
"In the last 10 years, Ebola is the single largest killer of apes. Poaching is a close second," said Peter Walsh, a member of IUCN's primate specialist group. "Ebola is knocking down populations to a level where they won't bounce back. The rate of decline is dizzying. If it continues, we'll lose them in 10-12 years."
Female gorillas only start reproducing at the age of 9 or 10 and only have one baby about every five years. Walsh said even in ideal conditions, it would take the gorillas decades to bounce back.
Hilton-Tailor said the plight of gorillas points up the need for better viral controls, and for an alternative source of food for people in the gorilla’s range, from Angola to Congo to Gabon.
Development is the culprit in the decline of the Yangtze River dolphin, also known as the baiji, Hilton-Tailor said. It is critically endangered and possibly extinct, with perhaps one or two individual creatures remaining in China.
Changes in river flows due to dams, pollution, over-fishing and the use of electric shocks to fish in the Yangtze system are all factors in the cetacean’s disappearance. Heavy river traffic in fast-developing China is another cause.
“Any poor dolphin would really have to do amazing acrobatics to avoid being hit by one of those ships,” Hilton-Tailor said.
Birds in decline
For birds, the Red List shows 1,221 species are considered threatened with extinction, and 189 species are listed as critically endangered. The overall status of the world’s birds has deteriorated steadily since 1988, when they were first comprehensively assessed.
Birds did see the only success story on this year's list, however. The Mauritius echo parakeet, which was one of the world’s rarest parrots 15 years ago, went from critically endangered to endangered — the only species to see its status improve.
The IUCN tied the improvement to close monitoring of nesting sites and supplementary feeding combined with a captive breeding and release program.
But it also expressed frustration that only one species on the list showed improvement.
"This is really worrying in light of government commitments around the world, such as the 2010 target to slow down the rate of biodiversity loss," said Jean-Christophe Vié, deputy chief of the IUCN’s species program. "Clearly, this shows that much more needs to be done."
The IUCN said that humans "are the main reason for most species’ decline" given their impact on habitat, introducing invasive species, unsustainable harvesting, pollution and disease. "Climate change is increasingly recognized as a serious threat, which can magnify these dangers," it said.
The group also noted that:
- Most threatened birds, mammals and amphibians are on the tropical continents — the regions whose forests are thought to hold most of Earth’s terrestrial and freshwater species.
- Of the countries assessed, Australia, Brazil, China and Mexico hold "particularly large numbers of threatened species."
- The vast majority of extinctions since 1500 AD have taken place on islands, but over the last 20 years extinctions on continents have become as common as island extinctions.
Jane Smart, head of the IUCN’s species Program, added that protecting wildlife is in the interest of humans. "Our lives are inextricably linked with biodiversity," she said, "and ultimately its protection is essential for our very survival."
The full Red List database is online at iucnredlist.org.