IUCN's credibility critically endangered


The IUCN is the world's main authority on the conservation status of species, so it is important that its recommendations are based on sound and open science. Recent events suggest that this is not always the case.


It is heart-warming when a politician as eminent as Norway's former prime minister Gro Harlem Brundtland writes “there is no other basis for sound political decisions than the best available scientific evidence. This is especially true in the fields of resource management and environmental protection”1. It is thus particularly sad that the influential World Conservation Union, the International Union for the Conservation of Nature (IUCN), one of whose main aims is to provide data for scientific assessments, is not only failing to do so, but appears to be withholding information.

Although the IUCN and its main subdivision, the Species Survival Commission (SSC), do not have any legally binding authority, their opinions are considered dependable: governments, scientists, journalists and others need a quick, reliable way to find out whether particular species are in danger of extinction without having to undertake lengthy research. They often turn to the IUCN's Red Lists (formerly called the Red Data Books), which place species in various categories of risk from ‘critically endangered’ to ‘least concern’. The IUCN also advises international conventions. At meetings of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), for instance, the IUCN produces analyses to help assess proposals affecting trade in endangered species. The IUCN's analyses are so influential because the original proposals are becoming too long and technical for national delegates to read (a recent proposal concerning sturgeon was 260 pages long), so many of them read the analyses instead.

In autumn 1996, the hawksbill sea turtle (Eretmochelys imbricata) was categorized in the Red Lists as critically endangered, meaning that “it is facing an extremely high risk of extinction in the wild in the immediate future”. To be placed in this category, a species must meet one of various criteria, for example an 80 per cent decline in numbers over the past 10 years or three generations, whichever is the longer. To make listings objective and transparent, background information should be available. “The factors responsible for triggering the criteria, especially where inference and projection are used, should at least be logged by the evaluator, even if they cannot be included in the published lists”2.

Attempts to obtain this information about the hawksbill turtle from the IUCN's marine turtle specialist group, which made the ‘critically endangered’ listing recommendation, were unsuccessful; more than 9 months after the listing this information has still not been distributed.

Judging a book by its cover: the controversial hawskbill document seen at the CITES meeting.

In the meantime, however, at the tenth CITES meeting in June in Zimbabwe, Cuba proposed to ‘downlist’ the population of hawksbills in its waters to allow for limited trade. At this meeting, a booklet entitled Biology and Status of the Hawksbill in the Caribbean was used by people lobbying against the Cuban proposal. The first page of text of this booklet mentions the critically endangered listing. But nobody could have known from the booklet that the background information supporting this highly controversial status had not been made available for evaluation. In response, it was said that the booklet was not an official document, only a draft. Bound in a shiny cover with three colours (see ), it does not look like a draft. The words ‘draft report’ only appear inside, where they can easily be missed. The cover states ‘Prepared by the IUCN/SSC Marine Turtle Specialist Group’. Many members of that group were never consulted about this document prepared in their name.

Unfortunately, this is not the only example of problems with the IUCN/SSC procedures. Some IUCN analyses, for example that concerning the Norwegian proposal for minke whales, have been criticized for containing misleading and wrong information. The analysis of the Cuban turtle proposal contained serious errors, as the authors acknowledged in a letter to the Cuban delegation apologizing for some of these. By then, however, the damage had been done.

The IUCN makes a distinction between analyses, which do not make recommendations, and position papers, which do. In the case of the hawksbills, no position paper was ever put out. Hence the IUCN is having its cake and eating it: it distributed a document damaging to the Cuban turtle proposal, but it never came out officially against that proposal. The worst feature of the analysis was not that it contained errors, but was the secrecy surrounding some of its sources of data. Many of these are cited in the reference list as “in litt”, with a name, meaning that the information is in a letter written to the IUCN by that person. The point of having reference lists is that people can look up the supporting details of statements in the text. But attempts to obtain copies of some of the letters cited in this analysis were unsuccessful. One of the letters apparently made allegations of illegal trade.

Thus the IUCN is disseminating statements derived from information that is not publicly available. What should be an analysis based on verifiable data has degenerated into assertion based on secret science. The hawksbill is listed as critically endangered, but supporting information has still not been made available. Problems with the Cuban proposal to CITES have been raised in private letters to the IUCN/SSC, and used in its analyses. No wonder some people are joking that SSC really stands for ‘secret science commission’.

If it wants to regain respect, the IUCN/SSC needs to take decisive, sweeping action. Fortunately, in the case of red listings made without provision of proper documentation — and there are many examples besides sea turtles — there is a simple and scientifically appropriate solution at hand: place these species immediately in the ‘data deficient’ category, which can be done quickly and simply on the Internet versions of the listings. The ‘data deficient’ category does not imply an absence or presence of threat2, but simply what it says. Such a listing might encourage those proposing a change in status to back their case by presenting data. But the data should be available at the start of the process, not added as an afterthought.


  1. 1

    Brundtland, G. H. Science 77, 457 (1997).

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  2. 2

    IUCN/SSC. IUCN Red List Categories (IUCN, Gland, Switzerland, 1994).

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Mrosovsky, N. IUCN's credibility critically endangered. Nature 389, 436 (1997). https://doi.org/10.1038/38873

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