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Rohlf D.J.,Lewis and Clark Law School | Carroll C.,Klamath Center for Conservation Research | Hartl B.,Center for Biological Diversity
BioScience | Year: 2014

The concept of conservation-reliant species has become increasingly prominent, particularly with species listed or under consideration for listing under the US Endangered Species Act (ESA). We have concerns about the trend toward what we see as an overly broad definition of conservation reliance. In addition to being of limited practical utility, overuse of the conservation reliant label can mask important legal and policy issues associated with species recovery and delisting. We propose a biology-based definition of conservation-reliant species - specifically, one based on the degree to which a species needs direct and ongoing human manipulation of its life cycle or environment in order to persist in the wild. This definition could assist managers in developing recovery priorities and allocating scarce recovery funds. In addition, a biological definition of conservation reliance could assist society and policymakers in considering whether the ESA's focus on self-sufficiency in the wild remains relevant as a definition of conservation success. © 2014 The Author(s) 2014. Source

Carroll C.,Klamath Center for Conservation Research | Lawler J.J.,University of Washington | Roberts D.R.,University of Alberta | Roberts D.R.,Albert Ludwigs University of Freiburg | Hamann A.,University of Alberta
PLoS ONE | Year: 2015

Metrics that synthesize the complex effects of climate change are essential tools for mappingfuture threats to biodiversity and predicting which species are likely to adapt in place to new climatic conditions, disperse and establish in areas with newly suitable climate, or facethe prospect of extirpation. The most commonly used of such metrics is the velocity of climate change, which estimates the speed at which species must migrate over the earth'ssurface to maintain constant climatic conditions. However, "analog-based" velocities, which represent the actual distance to where analogous climates will be found in the future, mayprovide contrasting results to the more common form of velocity based on local climate gradients. Additionally, whereas climatic velocity reflects the exposure of organisms to climatechange, resultant biotic effects are dependent on the sensitivity of individual species as reflected in part by their climatic niche width. This has motivated development of bioticvelocity, a metric which uses data on projected species range shifts to estimate the velocity at which species must move to track their climatic niche.We calculated climatic and bioticvelocity for the Western Hemisphere for 1961-2100, and applied the results to example ecological and conservation planning questions, to demonstrate the potential of such analog-based metrics to provide information on broad-scale patterns of exposure and sensitivity. Geographic patterns of biotic velocity for 2954 species of birds, mammals, andamphibians differed from climatic velocity in north temperate and boreal regions. However, both biotic and climatic velocities were greatest at low latitudes, implying that threats toequatorial species arise from both the future magnitude of climatic velocities and the narrow climatic tolerances of species in these regions, which currently experience low seasonaland interannual climatic variability. Biotic and climatic velocity, by approximating lower and upper bounds on migration rates, can inform conservation of species and locally-adaptedpopulations, respectively, and in combination with backward velocity, a function of distance to a source of colonizers adapted to a site's future climate, can facilitate conservation ofdiversity at multiple scales in the face of climate change. © 2015 Carroll et al.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Source

Carroll C.,Klamath Center for Conservation Research | Rohlf D.J.,Pacific Environmental Advocacy Center | Li Y.-W.,Defenders of Wildlife | Hartl B.,Center for Biological Diversity | And 2 more authors.
Conservation Letters | Year: 2015

Many species listed under the US Endangered Species Act (ESA) face continuing threats and will require intervention to address those threats for decades. These species, which have been termed conservation-reliant, pose a challenge to the ESA's mandate for recovery of self-sustaining populations. Most references to conservation-reliant species by federal agencies involve the restoration of population connectivity. However, the diverse threats to connectivity faced by different species have contrasting implications in the context of the ESA's mandate. For species facing long-term threats from invasive species or climate change, restoration of natural dispersal may not be technically feasible in the foreseeable future. For other species, restoration of natural dispersal is feasible, but carries economic and political cost. Federal agencies have used a broad definition of conservation reliance to justify delisting of species in the latter group even if they remain dependent on artificial translocation. Distinguishing the two groups better informs policy by distinguishing the technical challenges posed by novel ecological stressors from normative questions such as the price society is willing to pay to protect biodiversity, and the degree to which we should grow accustomed to direct human intervention in species' life cycles as a component of conservation in the Anthropocene Epoch. © 2014 The Authors. Conservation Letters published by Wiley Periodicals, Inc. Source

Carroll C.,Klamath Center for Conservation Research | Dunk J.R.,Humboldt State University | Dunk J.R.,U.S. Department of Agriculture | Moilanen A.,University of Helsinki
Global Change Biology | Year: 2010

The effectiveness of a system of reserves may be compromised under climate change as species' habitat shifts to nonreserved areas, a problem that may be compounded when well-studied vertebrate species are used as conservation umbrellas for other taxa. The Northwest Forest Plan was among the first efforts to integrate conservation of wide-ranging focal species and localized endemics into regional conservation planning. We evaluated how effectively the plan's focal species, the Northern Spotted Owl, acts as an umbrella for localized species under current and projected future climates and how the regional system of reserves can be made more resilient to climate change. We used the program maxent to develop distribution models integrating climate data with vegetation variables for the owl and 130 localized species. We used the program zonation to identify a system of areas that efficiently captures habitat for both the owl and localized species and prioritizes refugial areas of climatic and topographic heterogeneity where current and future habitat for dispersal-limited species is in proximity. We projected future species' distributions based on an ensemble of contrasting climate models, and incorporating uncertainty between alternate climate projections into the prioritization process. Reserve solutions based on the owl overlap areas of high localized-species richness but poorly capture core areas of localized species' distribution. Congruence between priority areas across taxa increases when refugial areas are prioritized. Although core-area selection strategies can potentially increase the conservation value and resilience of regional reserve systems, they accentuate contrasts in priority areas between species and over time and should be combined with a broadened taxonomic scope and increased attention to potential effects of climate change. Our results suggest that systems of fixed reserves designed for resilience can increase the likelihood of retaining the biological diversity of forest ecosystems under climate change. © 2009 Blackwell Publishing Ltd. Source

Carroll C.,Klamath Center for Conservation Research | Fredrickson R.J.,1310 Lower Lincoln Hills Drive | Lacy R.C.,Chicago Zoological Society
Conservation Biology | Year: 2014

Restoring connectivity between fragmented populations is an important tool for alleviating genetic threats to endangered species. Yet recovery plans typically lack quantitative criteria for ensuring such population connectivity. We demonstrate how models that integrate habitat, genetic, and demographic data can be used to develop connectivity criteria for the endangered Mexican wolf (Canis lupus baileyi), which is currently being restored to the wild from a captive population descended from 7 founders. We used population viability analysis that incorporated pedigree data to evaluate the relation between connectivity and persistence for a restored Mexican wolf metapopulation of 3 populations of equal size. Decreasing dispersal rates greatly increased extinction risk for small populations (<150-200), especially as dispersal rates dropped below 0.5 genetically effective migrants per generation. We compared observed migration rates in the Northern Rocky Mountains (NRM) wolf metapopulation to 2 habitat-based effective distance metrics, least-cost and resistance distance. We then used effective distance between potential primary core populations in a restored Mexican wolf metapopulation to evaluate potential dispersal rates. Although potential connectivity was lower in the Mexican wolf versus the NRM wolf metapopulation, a connectivity rate of >0.5 genetically effective migrants per generation may be achievable via natural dispersal under current landscape conditions. When sufficient data are available, these methods allow planners to move beyond general aspirational connectivity goals or rules of thumb to develop objective and measurable connectivity criteria that more effectively support species recovery. The shift from simple connectivity rules of thumb to species-specific analyses parallels the previous shift from general minimum-viable-population thresholds to detailed viability modeling in endangered species recovery planning. © 2013 Society for Conservation Biology. Source

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