Improving Peer Review of Listings and Recovery Plans under the Endangered Species Act

Abstract: We discuss several challenges encountered in peer review of Endangered Species Act listings and recovery plans, with particular attention to Meffe et al.'s (1998) statement on independent scientific review in natural resource management. First, Endangered Species Act listing documents and recovery plans pose a diverse array of scientific questions, and we suggest that overall effectiveness of peer review may be increased by segregating the critical issues and identifying specific reviewers for each issue. Some scientific reviewers may be unfamiliar with the decision standards prescribed by the Endangered Species Act and implementing policies. Unnecessary confusion could be prevented by providing reviewers with information about these standards and by requesting that reviewers clearly differentiate their assessment of decisions that must be based on available information from recommendations for future research. Short review periods constitute another constraint on careful review, but tight deadlines are fairly intractable in the context of the Endangered Species Act. We suggest that short time frames could be partially ameliorated by narrowing the scope of issues to be treated by each reviewer, and we discuss the issue of providing monetary compensation for efficient review. Finally, Endangered Species Act listing decisions and recovery planning may profit from more frequent peer review of intermediate analyses that precede publication of formal proposals or complete plans.     

Six Biological Reasons Why the Endangered Species Act Doesn't Work—And What to Do About It

Abstract: Law plays an important role in shaping land management decisions. The success of efforts to conserve biodiversity thus depends to a large degree on how well scientific knowledge is translated into public policy. Unfortunately, the Endangered Species Act, the United States's strongest legal tool for conserving bidodiversity, contains serious biological flaws. The statute itself, as well us agency regulations and policies that implement the law include provisions that fail to account accurately for important biological concepts such us ecosystem conservation, patch dynamics, and the probabilistic nature of stochastic threats to a species' persistence. Moreover, the procedures of federal agencies charged with implementing the Endangered Species Act in some cases make it difficult for interested outside reviewers to evaluate the agencies' scientific findings and methodology. However, the Endangered Species Act also gives interested individuals and groups several opportunities to provide input into the process of managing threatened and endangered species. Conservation biologists should practice focused advocacy by taking advantage of such opportunities to steer law in a more biologically sound direction.     

A Critique of the Recovery of Greenback Cutthroat Trout

Abstract: There are no examples of recovery of fish listed under the U.S. Endangered Species Act, but the number of federally threatened greenback cutthroat trout (  Oncorhynchus clarki stomias ) populations is approaching the delisting goal. We evaluated recovery of this subspecies in light of developing theory in conservation biology and with regard to recovery of other salmonids in the inland western United States. Four of the five criteria used to define populations that would count toward delisting appeared to underestimate the risk of extinction of those populations. Typically, recovery goals for numbers of greenback cutthroat trout populations were less stringent than those for other inland salmonids petitioned for listing or listed as threatened under the Endangered Species Act and were comparable to those for a federally endangered species. Before delisting is considered, we propose that historical populations be replicated in additional waters to protect genetic diversity and that existing populations be enlarged to reduce their vulnerability to demographic variation, to increase their access to refugia, and to permit reestablishment of mobile life histories. Existing stocks should also be evaluated to determine whether they represent distinct population segments.     

Molecular Taxonomy and the Conservation of the Red Wolf and Other Endangered Carnivores

Recent publications have reaffirmed that the red wolf ( Canis rufus ) is a hybrid of the coyote and the gray wolf. Besides the implications these results will likely have for future conservation efforts and allotment of resources through the Endangered Species Act for recovery of the red wolf, it is likely that broader consequences will be felt throughout the conservation community as species come under the scrutiny of a more powerful means of taxonomic identification. As molecular technology is refined in its ability to resolve taxonomic histories and uncertainties, it is likely that hybridization event(s) will be recognized in more species. This may be of particular importance for large carnivores, whose small population sizes make them susceptible to hybridization episodes with closely related, sympatric species. Because of negative perceptions, powerful antipredator advocates, conservation and resource constraints, and an enigmatic hybrid policy within the Endangered Species Act, how red-wolf taxonomy is decided by the U.S. Fish and Wildlife Service may affect the future of large carnivores in general.     

Resolving Critical Habitat Designation Failures: Reconciling Law, Policy, and Biology

Abstract:  The U.S. Endangered Species Act (ESA) requires designation of critical habitat concurrent with species listing. The U.S. Fish and Wildlife Service often has not designated critical habitat, based on the legal exceptions in the ESA of "not prudent" or "not determinable." This lack of habitat designation has led to numerous lawsuits and court orders to designate critical habitat for listed species. Court-mediated implementation of critical habitat is costly and delays listing for at-risk species. Legal, policy, judicial, and biological issues all contribute to the current inability of the law as enforced to lead to timely and cost-effective critical habitat designation. Although increased appropriations and delaying critical habitat designation until recovery planning have been proposed as solutions, we find that it will be essential to change the critical-habitat guidelines to a decision-analysis framework to make critical habitat scientifically and legally workable as a conservation tool.     

Accounting for Uncertainty in Making Species Protection Decisions

Abstract:  Uncertainty gives rise to two decision errors in implementing the U.S. Endangered Species Act: listing species that are not in danger of extinction and delisting species that are in danger of extinction. I evaluated four methods (minimum standard, precautionary principle, minimax regret criterion, adaptive management) for deciding whether to list or delist a species when there is uncertainty about how those decisions are likely to influence survival of the species. A safe minimum standard criterion preserves some minimum amount or safe standard (population) of a species unless maintaining that amount generates unacceptable social cost. The precautionary principle favors not delisting a species when there is insufficient evidence on the efficacy of state management plans for protecting them. A minimax regret criterion selects the delisting decision that minimizes the maximum loss likely to occur under alternative ecosystem states. When the cost of making a correct decision is less than the cost of making an incorrect decision, the minimax regret criteria indicates that delisting is the optimal decision. Active adaptive management employs statistically valid experiments to test hypotheses about the likely impacts of delisting decisions. Safe minimum standard and minimax regret criterion are not compatible with the U.S. Endangered Species Act. The precautionary principle comes closest to describing how federal agencies make delisting decisions. Active adaptive management is scientifically superior to the other methods but is costly and time consuming and may not be compatible with the U.S. National Environmental Policy Act.     

Why Economics Matters for Endangered Species Protection

Abstract: We offer three reasons why economics matters more to species protection than many people think and what this implies for the ongoing debate over the reauthorization of the Endangered Species Act of 1973. Economics matters because (1) human behavior generally, and economic parameters in particular, help determine the degree of risk to a species; (2) in a world of scarce resources, the opportunity cost of species protection—the costs of reduced resources for other worthwhile causes—must be taken into account in decision making; and (3) economic incentives are critical in shaping human behavior, and consequently the recovery of species. Endangered species protection that explicitly addresses these basic principles can avoid wasting valuable resources that yield no gain in species protection.     

Genetic Identification of Spotted Owls, Barred Owls, and Their Hybrids: Legal Implications of Hybrid Identity

Abstract:  Recent population expansion of Barred Owls (  Strix varia ) into western North America has led to concern that they may compete with and further harm the Northern Spotted Owl (  S. occidentalis caurina ), which is already listed as threatened under the U.S. Endangered Species Act (ESA). Because they hybridize, there is a legal need under the ESA for forensic identification of both species and their hybrids. We used mitochondrial control-region DNA and amplified fragment-length polymorphism (AFLP) analyses to assess maternal and biparental gene flow in this hybridization process. Mitochondrial DNA sequences (524 base pairs) indicated large divergence between Barred and Spotted Owls (13.9%). Further, the species formed two distinct clades with no signs of previous introgression. Fourteen diagnostic AFLP bands also indicated extensive divergence between the species, including markers differentiating them. Principal coordinate analyses and assignment tests clearly supported this differentiation. We found that hybrids had unique genetic combinations, including AFLP markers from both parental species, and identified known hybrids as well as potential hybrids with unclear taxonomic status. Our analyses corroborated the findings of extensive field studies that most hybrids genetically sampled resulted from crosses between female Barred Owls and male Spotted Owls. These genetic markers make it possible to clearly identify these species as well as hybrids and can now be used for research, conservation, and law enforcement. Several legal avenues may facilitate future conservation of Spotted Owls and other ESA-listed species that hybridize, including the ESA similarity-of-appearance clause (section 4[e]) and the Migratory Bird Treaty Act. The Migratory Bird Treaty Act appears to be the most useful route at this time.     

Taxonomic and Geographic Patterns of Decline for Threatened and Endangered Species in the United States

Abstract: Species listed under the U.S. Endangered Species Act (i.e., listed species) have declined to the point that the probability of their extinction is high. The decline of these species, however, may manifest itself in different ways, including reductions in geographic range, number of populations, or overall abundance. Understanding the pattern of decline can help managers assess extinction probability and define recovery objectives. Although quantitative data on changes in geographic range, number of populations, and abundance usually do not exist for listed species, more often qualitative data can be obtained. We used qualitative data in recovery plans for federally listed species to determine whether each listed species declined in range size, number of populations, or abundance relative to historical levels. We calculated the proportion of listed species in each state (or equivalent) that declined in each of those ways. Nearly all listed species declined in abundance, and range size or number of populations declined in approximately 80% of species for which those data were available. Patterns of decline, however, differed taxonomically and geographically. Declines in range were more common among vertebrates than plants, whereas population extirpations were more common among plants. Invertebrates had high incidence of range and population declines. Narrowly distributed plants and invertebrates may be subject to acute threats that may result in population extirpations, whereas vertebrates may be affected by chronic threats that reduce the extent and size of populations. Additionally, in the eastern United States and U.S. coastal areas, where the level of land conversion is high, a greater percentage of species’ ranges declined and more populations were extirpated than in other areas. Species in the Southwest, especially plants, had fewer range and population declines than other areas. Such relations may help in the selection of species’ recovery criteria.     

A simple economic model of endangered species preservation in the United States

Concern for the acceleration in threats to species diversity in the United States led to the passage of the Endangered Species Act of 1973. In this paper, this legislation is examined in an economic context. A simple model is developed where management and constraints on economic activity are substitutes in the production of species stocks. Whether economic growth constraints (the primary policy tool of the 1973 Act) are justified for preservation purposes depends on technical substitution possibilities, relative cost ratios, and the existence of budget constraints for species management. Since the same combination of these factors will not occur for all species, it is argued that more flexibility in endangered species policy may preserve the same levels of species stocks at lower costs to society.     

Law and Large Carnivore Conservation in the Rocky Mountains of the U.S. and Canada

The law governing large carnivores in the western U.S. and western Canada abounds in jurisdictional complexity. In the U.S., different federal and state laws govern large carnivore conservation efforts; species listed under the Endangered Species Act are generally protected, whereas those subject to state regulation can be hunted, trapped, or otherwise taken. Neither federal nor state environmental or land management laws specifically protect large carnivores, though these laws can be used to protect habitat. A similar situation prevails in Canada. Canadian federal law does not address large carnivore conservation, although the national parks provide some secure habitat. Provincial laws vary widely; none of these laws specifically protect large carnivores, but some provisions can be invoked to protect habitat. Although the two nations have not entered any bilateral treaties to protect large carnivores, several species receive limited protection under multilateral treaty obligations. Despite these jurisdictional complexities, the existing legal framework can be built upon to promote large carnivore conservation efforts, primarily through a legally protected reserve system. Whether the political will exists to utilize fully the available legal authorities remains to be seen.     

Voluntary conservation of endangered species: when does no regulatory assurance mean no conservation?

Voluntary conservation agreements are becoming increasingly important in implementing the Endangered Species Act on private land. We analyze when such agreements arise and what level of conservation they generate in the presence of uncertainty about future conservation benefits and irreversibility of habitat loss and species extinction. Our results suggest that the likelihood of an agreement and the resulting conservation levels depend on the background threat of regulation, the cost advantage offered by voluntary agreements, and the availability of assurances regarding future regulation. Under conditions likely to hold in practice, conservation agreements that offer assurances may generate higher levels of conservation and higher net social benefits than agreements that do not offer assurances. However, the resulting level of conservation will not be optimal, and may be lower than that attainable under regulation.     

Status of Species Conservation Banking in the United States

Abstract:  Receiving financial gains for protecting habitat may be necessary to proactively protect endangered species in the United States. Species conservation banking, the creation and trading of "credits" that represent biodiversity values on private land, is nearly a decade old. We detail the biological, financial, and political experience of conservation banking in the United States. We contacted agencies, nongovernmental organizations, and bank owners and compiled comprehensive accounts of the experiences of current banks. There are 76 properties identified as conservation banks in the United States, but only 35 of these are established under a conservation banking agreement approved by the U.S. Fish and Wildlife Service (USFWS). The 35 official conservation banks cumulatively cover 15,987 ha and shelter a range of biodiversity, including more than 22 species listed under the U.S. Endangered Species Act. Financial motives drove the establishment of 91% of conservation banks, and the majority of for-profit banks are breaking even or making money. With credit prices ranging from $3,000 to $125,000/0.41 ha (1 acre), banking agreements offer financial incentives that compete with development and provide a business-based argument for conserving habitat. Although the bureaucracy of establishing an agreement with the USFWS was burdensome, 63% of bank owners reported they would set up another agreement given the appropriate opportunity. Increasing information sharing, decreasing the time to establish agreements (currently averaging 2.18 years), and reducing bureaucratic challenges can further increase the amount of private property voluntarily committed to banking. Although many ecological uncertainties remain, conservation banking offers at least a partial solution to the conservation versus development conflict over biodiversity.     

Economies of Scope in Endangered-Species Protection: Evidence from Interest-Group Behavior

This paper looks for positive spillovers from the legal protection of one species to the welfare of others and for evidence of economies of scope in the costs associated with protecting species under the Endangered Species Act. The analysis uses data on the intensity of interest-group comment activity in response to proposals to protect new species. The results suggest that these phenomena are significant, strengthening arguments that wildlife-protection policy should be shifted toward species groups or ecosystems. However, the findings are also consistent with diminishing public willingness-to-pay for protected species in a given area, a pattern which also has public-policy implications.     

Correlates of Population Recovery Goals in Endangered Birds

Abstract: Endangered species recovery plans commonly set goals for population size that are used to define the success of recovery efforts. We examined variation in these population recovery goals for bird species listed under the U. S. Endangered Species Act to determine whether there were simple predictors of recovery population size. The median population sizes that must be met for a species to be removed from the list or downlisted to the threatened category are 4000 and 1500 respectively, but the thresholds varied considerably. Most variation in population recovery goals ( ≥75%) was explained by the population size when the recovery plan was written. Species listed when their population's size was relatively large have higher population recovery goals, whereas those listed when populations were small have lower population goals. Population sizes set for recovery also increased over time and were higher for species listed throughout the United States rather than for part of the country. In combination, these three variables explained 86% of the variance in population goals for delisting and 94% of the variance in goals for downlisting. Body mass, annual fecundity, maximum lifespan, whether the population was listed as threatened or endangered, and whether a formal population viability analysis was conducted were variables not significantly associated with population recovery goals. Thus, we found that variables relating to the circumstances under which the populations were listed could explain almost all of the variance in recovery population goals, and that biological traits of the endangered birds explained little of the variance.     

Genetic Data and the Listing of Species Under the U.S. Endangered Species Act

Abstract:  Genetic information is becoming an influential factor in determining whether species, subspecies, and distinct population segments qualify for protection under the U.S. Endangered Species Act. Nevertheless, there are currently no standards or guidelines that define how genetic information should be used by the federal agencies that administer the act. I examined listing decisions made over a 10-year period (February 1996–February 2006) that relied on genetic information. There was wide variation in the genetic data used to inform listing decisions in terms of which genomes (mitochondrial vs. nuclear) were sampled and the number of markers (or genetic techniques) and loci evaluated. In general, whether the federal agencies identified genetic distinctions between putative taxonomic units or populations depended on the type and amount of genetic data. Studies that relied on multiple genetic markers were more likely to detect distinctions, and those organisms were more likely to receive protection than studies that relied on a single genetic marker. Although the results may, in part, reflect the corresponding availability of genetic techniques over the given time frame, the variable use of genetic information for listing decisions has the potential to misguide conservation actions. Future management policy would benefit from guidelines for the critical evaluation of genetic information to list or delist organisms under the Endangered Species Act.     

Species‐level persistence probabilities for recovery and conservation status assessment

Recovery planning for species listed under the U.S. Endangered Species Act has been hampered by a lack of consistency and transparency, which can be improved by implementing a standardized approach for evaluating species status and developing measurable recovery criteria. However, managers lack an assessment method that integrates threat abatement and can be used when demographic data are limited. To help meet these needs, we demonstrated an approach for evaluating species status based on habitat configuration data. We applied 3 established persistence measures (patch occupancy, metapopulation capacity, and proportion of population lost) to compare 2 conservation strategies (critical habitat designated by the U.S. Fish and Wildlife Service and the Forest Service's Carbonate Habitat Management Strategy) and 2 threat scenarios (maximum limestone mining, removal of all habitat in areas with mining claims; minimum mining, removal of habitat only in areas with existing operations and high‐quality ore) against a baseline of existing habitat for 3 federally listed plant species. Protecting all area within the designated critical habitat maintained a similar level (83.9–99.9%) of species persistence as the baseline, whereas maximum mining greatly reduced persistence (0.51–38.4% maintained). The 3 persistence measures provided complementary insights reflecting different aspects of habitat availability (total area, number of patches, patch size, and connectivity). These measures can be used to link recovery criteria developed following the 3 R principles (representation, redundancy, and resilience) to the resulting improvements in species viability. By focusing on amount and distribution of habitat, our method provides a means of assessing the status of data‐poor species to inform decision making under the Endangered Species Act.     

The effectiveness of the US endangered species act: An econometric analysis using matching methods

Diametrically opposed views of the effectiveness of the United States Endangered Species Act (ESA) co-exist more than 30 years after the Act's creation. The evidence marshaled to date for and against the ESA suffers from a problem common in analyses of biodiversity protection measures: the absence of a well-chosen control group. We demonstrate how matching methods can be used to select such a control group and thereby estimate how species listed under the ESA would have fared had they not been listed. Our results show that listing a species under the ESA is, on average, detrimental to species recovery if not combined with substantial government funds. In contrast, listed species with such funding tend to improve. Our analysis offers not only new insights into a controversial debate, but also a methodology to guide conservation scientists in evaluating the effectiveness of society's responses to biodiversity loss.     

Developing a Criterion for Delisting the Southern Sea Otter under the U.S. Endangered Species Act

Recent surveys of recovery plans indicate that criteria, such as population sizes, for delisting species from the U.S. Endangered Species Act (ESA) are often unrealistically low by scientific standards. We describe the delisting criterion for the threatened southern sea otter (Enhydra lutris nereis) developed by the Southern Sea Otter Recovery Team. A major oil spill is the most serious threat to this sea otter population. After extensive modeling of oil spills, the recovery team concluded that it was not scientifically defensible to develop a delisting criterion in terms of a single probability of extinction over a specified time period. Instead, the team decided to define a size at which it would consider the population endangered and to consider the population threatened as long as a major oil spill might reduce it to that size. The effective population size (N_e) for endangered status was set at 500, estimated to be about 1850 otters. Using a spill the size of the Exxon Valdez spill (250,000 bbl), the oil spill model was iterated to generate a frequency distribution of the number of sea otters contacted by oil, from which the team estimated that less than 800 otters would be killed by 90% of the simulated spills. Thus, the delisting criterion was set at 1850 + 800 = 2650 individuals. There have been several proposals to improve the Endangered Species Act by providing quantitative guidance, in the form of specific probabilities of extinction within some time frame or specific criteria like those used by the World Conservation Union as to the levels of extinction risk represented by the terms "threatened" and "endangered." Experiences of the Sea Otter Recovery Team indicate that guidelines should not be overly rigid and should allow flexibility for dealing with specific situations. The most important consideration is to appoint a recovery team that is both technically well qualified and unconstrained by pressures from management agencies.     

Mitigation of Habitat "Take": Application to Habitat Conservation Planning

One of the most important provisions of the U.S. Endangered Species Act precludes the "taking" of listed species on both public and private land. In past Endangered Species Act litigation, take has been broadly interpreted to include the destruction or modification of habitats as well as the direct killing of animals. This requirement created an extensive burden on private landowners to provide habitats for listed species. This burden was substantially lessened when the ESA was modified in 1982 to allow incidental takings conditioned on preparation of a satisfactory "habitat conservation plan." Because the majority of listed species are imperiled due to habitat modification, most habitat conservation plans must demonstrate defensible methods to mitigate against incidental habitat loss. A review of HCPs for the Northern Spotted Owl ( Strix occidentalis), and other species, indicates that mitigation solutions are often arbitrary, lacking an empirical foundation in the species' life history requirements. Based on data from the Spotted Owl, we illustrate a biologically based method for estimating the areal requirements necessary to mitigate against the take of essential habitats. Toward this goal we adopt the concept of "core area," that portion of an animal's home range that receives disproportionate use. We estimated core areas by means of the adaptive kernel density function and tested against a null distribution of animal use that assumes a bivariate, uniform distribution of locations within the home range. The method we illustrate, which is defensible, repeatable, and empirical, is a clear improvement over the ad hoc methods used in many habitat conservation plans. Further, the methods we propose should be applicable to a large number of terrestrial species for which home range is a meaningful concept.