Biodiversity researchers warn that 20 percent of vertebrate
species are threatened with extinction, largely because of human
damage to habitats. But conservation efforts, they say, are
If a creature has a spine and walks, flies, swims, or crawls, it
may be in serious trouble.
Some 20 percent of all vertebrate species on Earth are threatened
by extinction, according to a newly published survey - a study the
research team involved says is the most exhaustive to date on
biodiversity among vertebrates.
The losses are due largely to human encroachment on habitat, over-
fishing and over-hunting, as well as the arrival of invasive species
in habitats whose natural inhabitants have no defenses against the
invaders, the study says.
But within an admittedly bleak global picture, the researchers
add, conservation efforts have halted the decline in some species
and brought others a significant step closer to recovery.
"The bad news can be extremely disheartening," says Ana
Rodrigues, a scientist with the Center for Functional and
Evolutionary Ecology in Paris and one of a team of 174 scientists
from 38 countries who co-authored the study.
"But our results show that conservation efforts are not wasted,"
Biodiversity refers to the variety of plant and animal species in
an ecosystem. Generally the greater the diversity, the more
resilient the ecosystem is to disturbances, either natural or man-
Using an internationally recognized "red list" index that tries
to capture changes in a species' population size, structure, and
geographic range, among other factors, the team found that without
conservation programs, biodiversity among birds and mammals would
have declined an additional 18 percent over the past 30 years. The
programs range from efforts to establish safe havens such as marine
protected areas or wildlife reserves to campaigns to battle invasive
The report draws on research conducted by some 3,000 scientists
worldwide. It was published Tuesday on the journal Science's website
as delegates from 194 countries were meeting in Nagoya, Japan, to
try to set conservation targets for the next decade under the UN's
Convention on Biological Diversity, which is scheduled to end Oct.
Eight years ago, parties to the convention agreed to
significantly reduce the rate of biodiversity loss by 2010. But in
April, a study published online in Science showed that the rate of
decline in biodiversity across a broad range of plants and animals
was not slowing. Countries had failed to meet the 2010 goal.
Losses in tropics
For this latest project, the team focused on vertebrates - a
group that includes animals that are most important to humans either
for food or for their cultural or social significance. The group
looked at 25,780 vertebrate species. …