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A species is conservation reliant when the threats that it faces cannot be eliminated, but only managed. There are two forms of conservation reliance: population- and threat-management reliance. We provide an overview of the concept and introduce a series of articles that examine it in the context of a range of taxa, threats, and habitats. If sufficient assurances can be provided that successful population and threat management will continue, conservation-reliant species may be either delisted or kept off the endangered species list. This may be advantageous because unlisted species provide more opportunities for a broader spectrum of federal, state, tribal, and private interests to participate in conservation. Even for currently listed species, the number of conservation-reliant species—84% of endangered and threatened species with recovery plans— and the magnitude of management actions needed to sustain the species at recovered levels raise questions about society's willingness to support necessary action.

One-third of the bird species listed under the US Endangered Species Act are endemic to Hawaii. One requirement of delisting a species is the elimination or abatement of threats to that species. More than 95% of Hawaii’s threatened and endangered species face multiple threats that cannot be eliminated (e.g., alien mammalian predators, invasive alien plants that alter habitat structure, disease). However, because we can manage many of the threats at scales at which the achievement of recovery goals is possible, these species could be delisted if conservation partners committed to the implementation of stewardship agreements to maintain viable populations following those populations’ delistings.

Habitat conservation plans (HCPs) permit the incidental take of threatened or endangered species listed under the federal Endangered Species Act. The US Fish and Wildlife Service (USFWS) and the NOAA Fisheries Service endorse multispecies HCPs, claiming that they offer advantages for both conservation and development. However, the conservation benefits of multispecies plans to individual covered species may be overestimated. We reviewed the species selected for coverage in 22 multispecies HCPs from USFWS Region 1. We found that conservation measures were often not clearly defined, and that the presence of the species in the planning area was not even confirmed for 41 percent of covered species. While we do not question the conservation value of multispecies plans, our study suggests that changes are needed to achieve full conservation potential.

epatriating an endangered species to its homeland is an attractive, although expensive, approach to saving rare or endangered species currently maintained in captivity. This approach is particularly popular among conservationists with ties to zoos. Among birds, for example, many species have been released in areas where populations have declined or disappeared. However, in a review of bird reintroductions, translocations, and introductions, Long (1981) estimated that approximately half of the more than 1000 cases have failed (see also Cade 1986). By comparison, few mammalian reintroductions have been attempted. Perhaps four or five of the fewer than 20 mammalian reintroductions using captive-bred animals have been successful in establishing viable populations (Wemmer and Derrickson 1987). But the successes, including the American bison (Bison bison) and the European wisent (Bison bonasus) (Campbell 1980, Conway 1980) demonstrate the positive impact that this technique can have on populations of threatened species. The American bison by 1889 had High costs, logistical difficulties, and the