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PLANS to save some of North America鈥檚 rarest plants and animals are backfiring.

Rather than focusing on 鈥渃auses c茅l茅bres鈥� such as the Californian condor, government conservationists in the US are taking a multi-species approach, trying to protect whole groups of endangered wildlife. But a survey reveals that the new policy is more difficult to implement, and is short-changing the very species it is designed to protect.

鈥淭here鈥檚 a serious problem and something should be done about it,鈥� says Alan Clark, a conservation biologist at the University of Washington in Seattle.

Whenever a species is listed as threatened or endangered under the US Endangered Species Act, biologists from the US Fish and Wildlife Service assess its status and the nature of the threats against it. They then outline the specific steps that should be taken to bring the species back from the brink.

Often these recovery plans deal with a single species, such as the condor or the grizzly bear. But since 1994 the USFWS has encouraged plans that cover several species at once. Over half of endangered plants and animals in the US are protected in this way.

This approach allows conservationists to coordinate their attempts to save rare wildlife. For example, in the Florida Everglades, the endangered wood stork requires lower water levels to feed than the snail kite, which is also endangered. Multi-species recovery plans allow biologists to balance these competing needs, while saving time and money.

To see how well the new strategy is working, Clark and Erik Harvey of Arizona State University in Tempe compared a random selection of 81 species covered by multi-species recovery plans with 100 species protected on their own. They scored each recovery plan according to a standardised questionnaire. The evaluation was part of a larger investigation by the Society for Conservation Biology.

They found that multi-species plans contained less information about the species鈥� habitat, ecology, and behaviour than single-species plans. That鈥檚 not surprising, because multi-species plans tend to include relatively obscure species, many of which are plants.

More disturbing, though, is the finding that even when the reasons for a species鈥� decline were understood, multi-species plans listed fewer steps that biologists might take to counteract the threats. There were also fewer proposals for monitoring the success of its recovery. And while 45 per cent of single-species plans were updated to reflect changing circumstances, only 20 per cent of multi-species plans were later improved.

This doesn鈥檛 mean that multi-species plans are intrinsically bad, says Clark, only that the USFWS needs more resources to expand its efforts. Deborah Crouse, a specialist in endangered species recovery at the USFWS in Arlington, Virginia, says that the service will take heed of Clark鈥檚 findings as it revises its recovery plan guidelines.