Global Extinctions Greater Risk Than Earlier Believed

by Danielle Knight

From birds and plants to reptiles and primates, the number of critically endangered species has increased in practically all types of species tracked by field biologists, according to the new list of endangered species released last month by the World Conservation Union (IUCN).

Known as the "2000 IUCN Red List of Threatened Species," the Geneva-based Organization's findings have become the most authoritative assessment of global bio-diversity loss, used by scientists and policy makers worldwide. The last Red List was released in 1996.

"The trends are distressing," said Russell Mittermeier, chair of IUCN's primate specialist group. "Many wonderful creatures will be lost in the first few decades of the 21st century unless we greatly increase levels of support, involvement and commitment to conservation."

There are huge gaps in knowledge about the number and types of species on the planet, he added. "The Red List reveals just the tip of the iceberg," he said.

Dwindling populations of species is usually due to a variety of factors, said the report. Usually, it is a combination of habitat loss and degradation combined with hunting or the introduction of non-native species that invade an ecosystem.

In the last 500 years, human activity has pushed 816 species to extinction. Since 1800, about 103 species have died out, indicating an extinction rate 50 times greater than the natural rate.

"Many species are lost before they are even discovered," said the IUCN report. The number of critically endangered mammals since 1996 has increased from 169 to 180 while the number of birds in this category increased from 168 to 182.

According to Mittermeier, the term "critically endangered" means that the number of species remaining in the wild may only be in the dozens or hundreds. "It means they are hanging by the skin of their teeth," he explained to journalists at a press conference here in Washington.

About 25 percent of all mammals, or 5,205 species, are listed as threatened with extinction. These are not considered critically endangered or at high risk of going extinct, but could end up on that list if there numbers continue to drop.

The greatest change among the mammals since the first Red List is in the number of threatened primates, which increased from 96 to 116. There are a total of about 600 primate species in the wild.

While these primates are not listed as critically endangered, this still means that one out of four primates are threatened. The number of critically endangered primates increased from 13 to 19 since 1996.

Increased habitat loss and hunting, particularly the bush-meat trade, accounted for most of the decline in populations of these primates, according to Mittermeier.

Field biologists studying primates recently declared a primate extinct. Known as Miss Waldron's red colobus, a loud red-cheeked monkey from the rainforest canopy of Ghana and the Ivory Coast, it was the first primate in several centuries to be labelled extinct.

"A healthy forest is loud, but this was like being in a deserted cathedral...you don't hear anything, you don't even hear birds," said W. Scott McGraw, an anthropologist with Ohio State University who had tried to track down the red colobus.

A bat species that was once only considered vulnerable by the conservation group is now listed as critically endangered. Found in small numbers on only about five small and remote Ogasawara or Bonin islands of Japan, the Bonin Fruit Bat has lost much of its habitat through deforestation on the islands.

Amongst bird species, the most significant changes in endangered status have been in the albatrosses and petrels. Sixteen albatross species are now threatened compared to only three in 1996, as a result of long-line fishing. Of the remaining five albatross species, four are now near-threatened, according to the Red List.

Threatened penguin species have doubled from five to 10, since 1996. Doves, parrots and perching birds (known as passerines), especially those species in Southeast Asia, have shown marked increases in threatened species due to the vast deforestation in countries such as the Philippines, said IUCN.

About 25 percent of reptiles are listed as threatened. The number of threatened reptiles increased from 253 in 1996 to 291 in 2000. This is "mostly due to a focused analysis of the status of freshwater turtles and tortoises, especially freshwater turtles in Southeast Asia," said the report. The number of critically endangered reptiles has increased from 10 to 24.

"The rapidly deteriorating status of tortoises and freshwater turtles in Southeast Asia is due to heavy exploitation for food and medicinal use," said IUCN. Hunting of these species is unregulated and unmanaged, and the hunting levels are "far too high" for the species to sustain itself, the report said.

"As populations disappear in Southeast Asia, there are disturbing signs that this trade is increasingly shifting to the Indian Subcontinent, and further afield to the Americas and Africa," the IUCN said.

The Red List contains 5,611 species of threatened plants, many of which are trees, since most plants have not been evaluated. According to Mittermeier, only 4 percent of the earth's plants have been thoroughly assessed for their level of threat.

One of the plants listed as critically endangered is the Mandrinette. A red-flowered shrub found only on the steep slopes of two mountains on the island of Mauritius in the Indian Ocean.

The species, known to have a population of 20 mature specimens, is not regenerating. IUCN speculates that this is probably because of competition from species not native to the area.

While the conservation group admitted that its assessments of the status of marine life is inadequate, it estimated that about 30 percent of fish species are listed as threatened with extinction.

IUCN added several fish, mostly species of rays and sharks, to the endangered list since 1996. One of the fish on the list is the Brazilian guitarfish, a species of ray found along the coast of southern Brazil that is listed as being critically endangered. Its number declined by 96 percent between 1984 and 1994 through over-fishing.

The Common Sawfish has been reclassified from endangered in 1996 to critically endangered today. Once common in the Mediterranean and Eastern Atlantic Ocean, this large species has now, along with all other sawfish, been eliminated from Europe and the Mediterranean. Its status in West Africa, its other habitat, is not known.

"Without timely intervention, it is likely that this sawfish will become extinct," said IUCN.

Most of the species threatened with extinction are located in countries with high amounts of bio-diversity, including Indonesia, India, Brazil, China, Mexico and Peru.

Therefore in order to maximize the funds spent on conservation, governments, institutions and researchers need to focus on these "hotspot" regions, according to Bill Konstant, deputy chair of IUCN's primate specialist group.

"For conservation planning and policy, our conservation dollars have to be focussed on the hotspots," he said.