HERE's an endangered species puzzler: If conservationists had to choose between the northern spotted owl and the tailed toad, which should it be?
University of California (Berkeley) biologist David B. Wake says he'd pick the tailed toad or its equivalent every time.
His reason goes to the heart of the international effort to preserve Earth's rich diversity of life.
It deals with what many scientists see as a fundamental weakness in that effort as nations begin to take up their responsibilities under the Convention on Biological Diversity, which came into force Dec. 29.
Dr. Wake notes that not all species have equal scientific value.
``Since we don't have enough money to save every endangered species,'' he says, ``let's get our priorities in order - but based on sound scientific knowledge, so we have confidence in the science when we say a species must be saved.''
That's where trouble lies.
Peter Raven, director of the Missouri Botanical Garden in St. Louis, says that it's appalling ``how really awful our knowledge [of biodiversity] is.''
The spotted owl vs. tailed toad puzzler provides a rare case where scientific knowledge is adequate to make an informed choice.
The importance of a species depends as much on its relation to other species as on any other single factor.
The spotted owl has close relatives.
The tailed toad is unique. Its lineage branched off the main evolutionary line of amphibians millions of years ago. If the toad became extinct, an important line of evolutionary history would be lost. That's not the case with the northern spotted owl.
This gives no comfort to loggers in the Pacific Northwest forest where the spotted owl lives. The tailed toad lives there too.
The forest may harbor other scientifically important species. The spotted owl has served well as a standard bearer for protecting this important forest habitat under the United States endangered species law.
But it will not always be the case that a highly visible and popular endangered species also is an indicator of a wildlife habitat that should be preserved.
That's why three major biological societies - the American Society of Plant Taxonomists, the Society of Systematic Biologists, and the Willi Hennig Society - are calling for a global effort to systematically catalog Earth's diverse species and chart their relationships to one another.
The societies launched their campaign for this Systematics Agenda 2000 effort in San Francisco last month during the annual meeting of the American Association for the Advancement of Science. They will pursue it in a symposium at the Royal Society in London April 12, and at a meeting organized by the French Systematics Society in Paris April 15.
Dr. Raven and his colleagues estimate it will take 25 years and cost participating nations some $3 billion a year to do the survey properly. Much of the cost would come from training and equipping scientists in developing countries.
This is an essential program. So far, 36 nations have ratified the biodiversity treaty - enough to bring it into force. Another 131 signatories, including the United States, are waiting to ratify it.
The treaty commits these nations to develop plans for conservation and economic growth that will preserve biodiversity and endangered species. Their planners will be working from ignorance without the knowledge that Systematics Agenda 2000 would provide.
Developed countries will have to help third-world nations meet this commitment. That means not only providing financial aid, but more importantly, providing the expertise to help them build their own biological survey systems.