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If scientists are to prevent even more of the Earth’s species from sliding
into oblivion, they must rethink their research methods, and also tackle
the social, political and economic aspects of the problem. That was the
message to researchers when they gathered at the meeting of the World Conservation
Union (IUCN) at Perth last month. ‘Enough is enough,’ said George Rabb,
director of the Chicago Zoological Park, and head of the IUCN’s commission
on species survival.

Traditionally, scientists have viewed the extinction of plants and animals
as predominantly a biological problem – with dwindling populations in shrinking
fragments of natural habitat. The emphasis has been on field studies, captive
breeding programmes, reintroduction projects, techniques for in vitro fertilisation,
and the development of ‘banks’ of seeds, embryos and genes. But this approach
will not be enough say many scientists.

‘We can’t study the trees, the monkeys, the elephants and expect to
save the tropical forests; it is a social, political and economic problem,’
said Jeffrey McNeely, the IUCN’s chief conservation officer.

While the asembled scientists acknowledged that they cannot solve these
broader issues, they agreed that they could bring clarity and scientific
rigour to the growing public debate about the loss of biodiversity. Walter
Reid of the World Resources Institute (WRI) in Washington DC thinks that
researchers must begin by providing sound data on the magnitude of the ‘extinction
crisis’: how many species are being lost and at what rate?

Estimates vary widely. At the Perth meeting, rates cited by experts
ranged from one species lost per hour to one per day. Virtually all these
estimates are flawed, argues Reid, and there are relatively few hard figures.
The largest core of data on the decline of species comes from the World
Conservation Monitoring Centre in Britain; it lists 311 scientifically described
species which have disappeared since 1600. But the WCMC makes no estimate
of the overall rate of extinction.

According to Ulysses Seal of the University of Minnesota, who is a member
of the IUCN’s commission on species survival, the problem with existing
estimates is that they are based on slim, highly skewed data. Global rates
of extinction are calculated using mathematical models which are usually
‘fed’ data from tropical rainforests. There is little uniformity of models
or of sampling techniques, he said.

Seal believes that it is impossible to establish a firm rate of extinction
when scientists have no idea how many species exist on Earth. There could
be anything from 5 million species or more (see ‘counting species one by
one’, ¿ìè¶ÌÊÓƵ, 11 August 1990). ‘This puts in a large factor of uncertainty,’
Seal noted. ‘The uncertainty may be anywhere from three- to tenfold.’

But extinction rates may not be the best measure of the health of the
planet’s species. Nevertheless, those assembled in Perth concluded that
the scientific community must deliver such information to policy makers.
And it is essential that scientists do not make ‘extravagant claims out
of our worst fears’, cautions Seal. This would make it easier for politicians
to dismiss calls for action. He points to how governments have dragged their
feet over climate change and depletion of the ozone layer.

Vernon Heywood, chief scientist at the IUCN, adds that well-intentioned,
but exaggerated, estimates of the problem erode the credibility of scientists.
Some organisations have maintained a ‘policy of silence’ regarding extinction
rates, he said. They are concerned, reports Heywood, that if they criticise
some figures as too high, this could be misinterpreted to mean that the
loss of the species is not as serious as has been claimed.

To begin a thorough assessment of the extinction problem, a group of
scientists – including McNeely and Kenton Miller of the WRI, and Russell
Mitermeier and Timothy Werner of Conservation International in Washington
DC – has identified key areas for further research.

Foremost, they feel that scientists at museums, botanical gardens, universities
and research stations should join forces to record the world’s species through
basic taxonomic and biological survey work. The group also calls for extensive
ecological field studies to discover the population dynamics of species
of particular concern to researchers, and determine the effects of breaking
up tracts of habitat into fragments and possible procedures for managing
the problem.

Heywood, however, warns scientists that, unless they structure their
methodology carefully, this enormous research effort will never get off
the ground. He believes there are simply not enough scientific and financial
resources available at present to classify all organisms, even assuming
a modest total of 30 million living species.

‘It would be quite absurd to make the case to governments that there
are 30 million species out there and we ought to do something about it,’
he told the experts gathered at Perth. ‘We can’t describe every last entity
of biodiversity.’

Heywood reasons that the answer is to set clear research priorities.
To accomplish this aim, he says, scientists can choose several research
priorities. They could focus on ‘keystone’ or target species of pivotal
ecological importance. They could identify ‘economically valuable’ species,
such as crop or medicinal plants. They could work with species known by
researchers to be endangered, or they could describe biodiversity at the
‘ecosystem level’, unravelling the many and diverse ways in which plants
and animals in a particular geographic area function together.

The theory and methodology behind each of these procedures, however,
is still evolving. For instance, lacking a solid understanding of the organisms
in specific ecosystems, researchers have had difficulty identifying keystone
species. The selection of economically important species will vary from
one interest group to another. Likewise, the scientists assembled in Perth
disagreed over whether it was possible to describe meaningfully the relationships
existing between the organisims in an ecosystem.

The setting of research priorities is further complicated by the fact
that all priorities are based on prior value judgments, says Ronald Engle,
chairman of the IUCN ethics, culture and conservation working group. ‘There
is no way of talking about biodiversity, scientific or otherwise, or acting
on its behalf, that does not involve human interpretation,’ he said on behalf
of the 70-plus scientists who had participated in the IUCN ethics task force.

Engel is critical of the scientific community for assuming that its
actions are objective. Because scientists, generally, have not sorted out
their own ethical positions, he argues, they have been unable to participate
properly in the public discussion of extinctions and biodiversity. And he
feels the involvement of scientists is sorely needed. ‘Most discussion of
environmental issues and ethics is so abstract as to be either useless or
»å²¹²Ô²µ±ð°ù´Ç³Ü²õ.’

While his colleagues wrestle with ethics and priorities, Rabb is ‘networking’
to save species. If scientists are to come to grips with the extinction
problem, they must seek expertise outside their usual professional disciplines,
he said. For instance, herpetologists cannot alone discover precisely why
many frog species around the world are in decline. They must talk to chemists,
mathematicians, botanists, reproductive biologists, and even climatologists,
he believes. To this end, Rabb spent last summer pulling together an amphibian
‘task force’ under the auspices of the IUCN.

The new frog team will join the hundred or so specialists groups now
coordinated by Rabb and the IUCN species survival commission. Each of the
volunteer groups draws together experts from around the world, they meet
in an informal setting and focus on a species – from bamboo to orchids,
from Asian rhinos to the Puerto Rican parrot.

Groups integrate data, identify problems and involve appropriate national
agencies, research institutions and conservation organisations in species
survival projects. Most importantly, the groups develop detailed plans for
preserving ‘their’ particular species. For example, there are now survival
plans for dolphins, porpoises and whales, and for the Bali starling. Other
groups are in the pipeline.

Yet scientists must become ‘proactive’ if they truly want to see the
fruits of their research flourish, McNeely believes. Consequently, he has
led a push by the IUCN, the UN Environment Programme and WRI to mobilise
scientists and conservationists worldwide.

The outcome is the Biodiversity Conservation Strategy Programme (BCSP)
with ‘the immediate, practical goal to take steps to keep losses to biological
diversity to a minimum and to manage our living resource base ·É¾±²õ±ð±ô²â’. When
the BCSP is fully operational in 1992, an international coordinating group
will work with participating members. To date, more than 30 organisations
are involved, including the WCMC, the Smithsonian Institution and the Ramsar
Conservation Secretariat.

Between now and 1992, BCSP organisers plan to develop a biodiversity
conservation strategy which will outline concrete steps that can be taken
to achieve global goals while meeting local needs. To make information about
the wellbeing of the Earth’s species widely available, the SCSP will produce
a biodiversity status report for scientists, policy makers and conservationists.
Those efforts will be bolstered by a decade action plan. Very simply, the
intent of the plan is to give assistance and structure to concerned institutions
and individuals as they fight to ‘defend, understand, and use biodiversity
·É¾±²õ±ð±ô²â’.

According to McNeely, much of the success of the BCSP and other schemes
for survival of species depends on the willingness of scientists to work
together with social scientists. He observes that political scientists can
assess the way decisions about scientific recommendations are made, anthropologists
can learn how people use local species and economists can demonstrate the
financial benefits of biodiversity. For instance, ‘gorilla tourism’ is Rwanda’s
largest source of foreign exchange, McNeely said, and research projects
in Costa Rica’s Guanacaste National Park add a sum of roughly US $200,000
to the local economy.

Connie Lewis of Keyston Center, a Colorado-based ‘think tank’ agrees.
At the December meeting, Lewis and her associates, Michael Lesnick and Margot
Smit, argued that experienced negotiators can help to diffuse conflicts
that hinder the adoption of scientific recommendations. Examples include
the ownership of biological resources, compensation for diminished access
to declining species and ‘bureaucratic battles’ between governments and
institutions.

It may make many scientists unconfortable, but the consensus from the
Perth meeting is that scientists must learn to adjust to being political
players in the fight to preserve the planet’s biodiversity. As McNeely commented:
‘It is time to go on the offensive, to stop fighting species’ extinctions
as if they were a series of discrete battles. We need to get in front of
the problems, and attack them at their social, economic and political source.

DOCUMENTING DISAPPEARING SPECIES

Extinction of species is a natural process. The fossil record indicates
that most, if not all, species have a finite lifespan, averaging somewhere
between 1 and 10 million years. There is no doubt, however, that since their
appearance on the planet, human beings have triggered extinctions on a scale
and a rate comparable with the major extinction events of the geological
past.

In a preliminary report on global diversity, the World Conservation
Monitoring Centre, in Cambridge, lists 311 scientifically described species
which have perished since 1600. That figure includes 96 invertebrates, 24
fish, 20 reptiles, 117 birds and 54 mammals. In addition, 13 species – the
American black-footed ferret, the bison-like wisent, the dromedary, the
Arabian oryx, Przewalski’s horse, Pere David’s deer and seven species of
Polynesian tree snails – have been exterminated in the wild, surviving only
in captivity.

The WCMC data show that islands are the most important sites of known
extinctions. More than 180 of the documented extinctions have taken place
on islands. This pattern was established early on. For example, when the
Polynesians settled the Hawaiian islands during the 4th and 5th centuries,
they exterminated roughly half of the 100 local land birds.

Island birds are at particular risk. More than 90 per cent of recorded
bird extinctions since 1600 have been on islands. There are several possible
reasons for the increased vulnerability of birds. The most obvious is that
island species have limited ranges and often low populations, so that they
are most likely to be exterminated by a single cause or event. In addition,
island species, such as the flightless dodos of the Mascarene Islands, seem
particularly susceptible to predation from introduced species.

The WCMC is presently compiling a comprehensive compendium of biodiversity
data. The full document, entitled Global Biodiversity: Status of the Earth’s
Living Resources, will be published in 1992.