Conservation resource allocation, small population resiliency, and the fallacy of conservation triage (original) (raw)
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On the Issues of Triage in Conservation
2016
The process of determining the priority of patients’ treatment based on the severity of their condition is termed triage. This principle attempts to ration the treatment of patients efficiently in the midst of insufficient resources for all to be treated immediately. In a conservation context, triage is the considered to be a process of prioritizing the allocation of limited resources to maximize conservation returns in the midst of a constrained budget. This practice requires accounting for the cost, benefits and likelihood of success for such alternative conservation efforts as protection, restoration, pest eradication, education and training. It seems more attention is paid to considering the probability of success and cost, prioritization of conservation efforts for threatened and endangered species than focusing on factors measuring risk of extirpation. This paper provides additional insight to reasons why we should reject triage. It also tried to direct attention to what is es...
Conservation-reliant species and the future of conservation
Conservation Letters, 2010
Species threatened with extinction are the focus of mounting conservation concerns throughout the world. Thirty-seven years after passage of the U.S. Endangered Species Act in 1973, we conclude that the Act's underlying assumption-that once the recovery goals for a species are met it will no longer require continuing management-is false. Even when management actions succeed in achieving biological recovery goals, maintenance of viable populations of many species will require continuing, species-specific intervention. Such species are "conservation reliant." To assess the scope of this problem, we reviewed all recovery plans for species listed as endangered or threatened under the Act. Our analysis indicates that 84% of the species listed under the Act are conservation reliant. These species will require continuing, long-term management investments. If these listed species are representative of the larger number of species thought to be imperiled in the United States and elsewhere, the challenge facing conservation managers will be logistically, economically, and politically overwhelming. Conservation policies will need to be adapted to include ways of prioritizing actions, implementing innovative management approaches, and involving a broader spectrum of society.
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.
Objectives for Multiple‐Species Conservation Planning
Conservation Biology, 2006
The first step in conservation planning is to identify objectives. Most stated objectives for conservation, such as to maximize biodiversity outcomes, are too vague to be useful within a decision-making framework. One way to clarify the issue is to define objectives in terms of the risk of extinction for multiple species. Although the assessment of extinction risk for single species is common, few researchers have formulated an objective function that combines the extinction risks of multiple species. We sought to translate the broad goal of maximizing the viability of species into explicit objectives for use in a decision-theoretic approach to conservation planning. We formulated several objective functions based on extinction risk across many species and illustrated the differences between these objectives with simple examples. Each objective function was the mathematical representation of an approach to conservation and emphasized different levels of threat. Our objectives included minimizing the joint probability of one or more extinctions, minimizing the expected number of extinctions, and minimizing the increase in risk of extinction from the best-case scenario. With objective functions based on joint probabilities of extinction across species, any correlations in extinction probabilities had to be known or the resultant decisions were potentially misleading. Additive objectives, such as the expected number of extinctions, did not produce the same anomalies. We demonstrated that the choice of objective function is central to the decision-making process because alternative objective functions can lead to a different ranking of management options. Therefore, decision makers need to think carefully in selecting and defining their conservation goals.
Prioritizing revived species: what are the conservation management implications of de‐extinction?
Functional Ecology, 2016
• De-extinction technology that brings back extinct species, or variants on extinct species, is becoming a reality with significant implications for biodiversity conservation. If extinction could be reversed, there are potential conservation benefits and costs that need to be carefully considered before such action is taken. • Here, we use a conservation prioritization framework to identify and discuss some factors that would be important if de-extinction of species for release into the wild were a viable option within an overall conservation strategy. • We particularly focus on how de-extinction could influence the choices that a management agency would make with regards to the risks and costs of actions, and how these choices influence other extant species that are managed in the same system. • We suggest that a decision science approach will allow for choices that are critical to the implementation of a drastic conservation action, such as de-extinction, to be considered in a deliberate manner while identifying possible perverse consequences.
Optimal Allocation of Conservation Resources to Species That May Be Extinct
2010
Statements of extinction will always be uncertain because of imperfect detection of species in the wild. Two errors can be made when declaring a species extinct. Extinction can be declared prematurely, with a resulting loss of protection and management intervention. Alternatively, limited conservation resources can be wasted attempting to protect a species that no longer exists. Rather than setting an arbitrary level of certainty at which to declare extinction, we argue that the decision must trade off the expected costs of both errors. Optimal decisions depend on the cost of continued intervention, the probability the species is extant, and the estimated value of management (the benefit of management times the value of the species). We illustrated our approach with three examples: the Dodo (Raphus cucullatus), the Ivory-billed Woodpecker (U.S. subspecies Campephilus principalis principalis), and the mountain pygmy-possum ( Burramys parvus). The dodo was extremely unlikely to be extant, so managing and monitoring for it today would not be cost-effective unless the value of management was extremely high. The probability the Ivory-billed woodpecker is extant depended on whether recent controversial sightings were accepted. Without the recent controversial sightings, it was optimal to declare extinction of the species in 1965 at the latest. Accepting the recent controversial sightings, it was optimal to continue monitoring and managing until 2032 at the latest. The mountain pygmy-possum is currently extant, with a rapidly declining sighting rate. It was optimal to conduct as many as 66 surveys without sighting before declaring the species extinct. The probability of persistence remained high even after many surveys without sighting because it was difficult to determine whether the species was extinct or undetected. If the value of management is high enough, continued intervention can be cost-effective even if the species is likely to be extinct.