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Sandretti-Silva G, Vannucchi FS, Teixeira L, Tan TY, Mori GM, Reinert BL, Bornschein MR. Short-term extinction predicted by population viability analysis for a Neotropical salt marsh endemic bird. ENVIRONMENTAL MONITORING AND ASSESSMENT 2024; 196:520. [PMID: 38713379 DOI: 10.1007/s10661-024-12618-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Accepted: 04/12/2024] [Indexed: 05/08/2024]
Abstract
Salt marshes pose challenges for the birds that inhabit them, including high rates of nest flooding, tipping, and predation. The impacts of rising sea levels and invasive species further exacerbate these challenges. To assess the urgency of conservation and adequacy of new actions, researchers and wildlife managers may use population viability analyses (PVAs) to identify population trends and major threats. We conducted PVA for Formicivora acutirostris, which is a threatened neotropical bird species endemic to salt marshes. We studied the species' demography in different sectors of an estuary in southern Brazil from 2006 to 2023 and estimated the sex ratio, longevity, productivity, first-year survival, and mortality rates. For a 133-year period, starting in 1990, we modeled four scenarios: (1) pessimistic and (2) optimistic scenarios, including the worst and best values for the parameters; (3) a baseline scenario, with intermediate values; and (4) scenarios under conservation management, with increased recruitment and/or habitat preservation. Projections indicated population decline for all assessment scenarios, with a 100% probability of extinction by 2054 in the pessimistic scenario and no extinction in the optimistic scenario. The conservation scenarios indicated population stability with 16% improvement in productivity, 10% improvement in first-year survival, and stable carrying capacity. The disjunct distribution of the species, with remnants concentrated in a broad interface with arboreal habitats, may seal the population decline by increasing nest predation. The species should be considered conservation dependent, and we recommend assisted colonization, predator control, habitat recovery, and ex situ conservation.
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Affiliation(s)
- Giovanna Sandretti-Silva
- Departamento de Ciências Biológicas e Ambientais, Universidade Estadual Paulista (UNESP), Instituto de Biociências, Praça Infante Dom Henrique, S/No, São Vicente, 11330-900, Brazil.
| | - Fabio Stucchi Vannucchi
- Departamento de Ciências Biológicas e Ambientais, Universidade Estadual Paulista (UNESP), Instituto de Biociências, Praça Infante Dom Henrique, S/No, São Vicente, 11330-900, Brazil
| | - Larissa Teixeira
- Mater Natura - Instituto de Estudos Ambientais, Rua Emiliano Perneta, 297, Conjunto 122, Curitiba, 80010-050, Brazil
| | - Tjui Yeuw Tan
- Wageningen University & Research, Aquaculture and Fisheries Group, Korringaweg, 7, Yerseke, 4401 NT, The Netherlands
- Aquaculture and Fisheries Group, Wageningen University & Research, De Elst, 1, Wageningen, 6708 WD, The Netherlands
| | - Gustavo Maruyama Mori
- Departamento de Ciências Biológicas e Ambientais, Universidade Estadual Paulista (UNESP), Instituto de Biociências, Praça Infante Dom Henrique, S/No, São Vicente, 11330-900, Brazil
| | - Bianca Luiza Reinert
- Departamento de Ciências Biológicas e Ambientais, Universidade Estadual Paulista (UNESP), Instituto de Biociências, Praça Infante Dom Henrique, S/No, São Vicente, 11330-900, Brazil
| | - Marcos R Bornschein
- Departamento de Ciências Biológicas e Ambientais, Universidade Estadual Paulista (UNESP), Instituto de Biociências, Praça Infante Dom Henrique, S/No, São Vicente, 11330-900, Brazil.
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Morris AB, Visger CJ, Fox SJ, Scalf C, Fleming S, Call G. Defining Populations and Predicting Future Suitable Niche Space in the Geographically Disjunct, Narrowly Endemic Leafy Prairie-Clover ( Dalea foliosa; Fabaceae). PLANTS (BASEL, SWITZERLAND) 2024; 13:495. [PMID: 38498467 PMCID: PMC10891826 DOI: 10.3390/plants13040495] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 01/30/2024] [Accepted: 02/06/2024] [Indexed: 03/20/2024]
Abstract
Conservation actions for rare species are often based on estimates of population size and number, which are challenging to capture in natural systems. Instead, many definitions of populations rely on arbitrarily defined distances between occurrences, which is not necessarily biologically meaningful despite having utility from a conservation management perspective. Here, we introduce a case study using the narrowly endemic and highly geographically disjunct leafy prairie-clover (Dalea foliosa), for which we use nuclear microsatellite loci to assess the current delimitations of populations and management units across its entire known range. We model future potential suitable niche space for the species to assess how currently defined populations could fare under predicted changes in climate over the next 50 years. Our results indicate that genetic variation within the species is extremely limited, particularly so in the distal portions of its range (Illinois and Alabama). Within the core of its range (Tennessee), genetic structure is not consistent with populations as currently defined. Our models indicate that predicted suitable niche space may only marginally overlap with the geology associated with this species (limestone glades and dolomite prairies) by 2070. Additional studies are needed to evaluate the extent to which populations are ecologically adapted to local environments and what role this could play in future translocation efforts.
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Affiliation(s)
- Ashley B. Morris
- Department of Biology, Furman University, Greenville, SC 29613, USA;
- Independent Researcher, San Antonio, TX 78247, USA;
| | - Clayton J. Visger
- Department of Biological Sciences, California State University, Sacramento, CA 95819, USA;
| | - Skyler J. Fox
- Department of Biology, Furman University, Greenville, SC 29613, USA;
- Department of Biology, Georgia Southern University, Statesboro, GA 30458, USA
| | | | - Sunny Fleming
- Environmental Systems Research Institute, Inc. (ESRI), Redlands, CA 92373, USA;
| | - Geoff Call
- Tennessee Ecological Services Field Office, U.S. Fish and Wildlife Service, Cookeville, TN 38501, USA;
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3
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Merli E, Mattioli L, Bassi E, Bongi P, Berzi D, Ciuti F, Luccarini S, Morimando F, Viviani V, Caniglia R, Galaverni M, Fabbri E, Scandura M, Apollonio M. Estimating Wolf Population Size and Dynamics by Field Monitoring and Demographic Models: Implications for Management and Conservation. Animals (Basel) 2023; 13:1735. [PMID: 37889658 PMCID: PMC10252110 DOI: 10.3390/ani13111735] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 05/04/2023] [Accepted: 05/18/2023] [Indexed: 10/29/2023] Open
Abstract
We estimated the current size and dynamics of the wolf population in Tuscany and investigated the trends and demographic drivers of population changes. Estimates were obtained by two different approaches: (i) mixed-technique field monitoring (from 2014 to 2016) that found the minimum observed pack number and estimated population size, and (ii) an individual-based model (run by Vortex software v. 10.3.8.0) with demographic inputs derived from a local intensive study area and historic data on population size. Field monitoring showed a minimum population size of 558 wolves (SE = 12.005) in 2016, with a density of 2.74 individuals/100 km2. The population model described an increasing trend with an average annual rate of increase λ = 1.075 (SE = 0.014), an estimated population size of about 882 individuals (SE = 9.397) in 2016, and a density of 4.29 wolves/100 km2. Previously published estimates of wolf population were as low as 56.2% compared to our field monitoring estimation and 34.6% in comparison to our model estimation. We conducted sensitivity tests to analyze the key parameters driving population changes based on juvenile and adult mortality rates, female breeding success, and litter size. Mortality rates played a major role in determining intrinsic growth rate changes, with adult mortality accounting for 62.5% of the total variance explained by the four parameters. Juvenile mortality was responsible for 35.8% of the variance, while female breeding success and litter size had weak or negligible effects. We concluded that reliable estimates of population abundance and a deeper understanding of the role of different demographic parameters in determining population dynamics are crucial to define and carry out appropriate conservation and management strategies to address human-wildlife conflicts.
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Affiliation(s)
- Enrico Merli
- Department of Veterinary Medicine, University of Sassari, 07100 Sassari, Italy
| | - Luca Mattioli
- Wildlife Service, Tuscany Region, 50127 Florence, Italy
| | - Elena Bassi
- Department of Veterinary Medicine, University of Sassari, 07100 Sassari, Italy
| | - Paolo Bongi
- Department of Veterinary Medicine, University of Sassari, 07100 Sassari, Italy
| | - Duccio Berzi
- Department of Veterinary Medicine, University of Sassari, 07100 Sassari, Italy
| | - Francesca Ciuti
- Department of Veterinary Medicine, University of Sassari, 07100 Sassari, Italy
| | - Siriano Luccarini
- Department of Veterinary Medicine, University of Sassari, 07100 Sassari, Italy
| | - Federico Morimando
- Department of Veterinary Medicine, University of Sassari, 07100 Sassari, Italy
| | - Viviana Viviani
- Department of Veterinary Medicine, University of Sassari, 07100 Sassari, Italy
| | - Romolo Caniglia
- Unit for Conservation Genetics (BIO-CGE), Italian Institute for Environmental Protection and Research (ISPRA), 40064 Bologna, Italy
| | | | - Elena Fabbri
- Unit for Conservation Genetics (BIO-CGE), Italian Institute for Environmental Protection and Research (ISPRA), 40064 Bologna, Italy
| | - Massimo Scandura
- Department of Veterinary Medicine, University of Sassari, 07100 Sassari, Italy
| | - Marco Apollonio
- Department of Veterinary Medicine, University of Sassari, 07100 Sassari, Italy
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4
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Brandhuber M, Atkinson S, Cunningham C, Roth T, Curry E. Assessing Dehydroepiandrosterone Sulfate (DHEAS) as a novel biomarker for monitoring estrus and successful reproduction in polar bears. Gen Comp Endocrinol 2023; 338:114276. [PMID: 36940836 DOI: 10.1016/j.ygcen.2023.114276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 03/13/2023] [Accepted: 03/17/2023] [Indexed: 03/23/2023]
Abstract
Polar bears (Ursus maritimus) in the wild are under threat due to climate change, primarily loss of sea ice, and experience poor reproductive success in zoos. The polar bear is a seasonally polyestrous species that exhibits embryonic diapause and pseudopregnancy, complicating characterization of reproductive function. Fecal excretion of testosterone and progesterone have been studied in polar bears, but accurately predicting reproductive success remains difficult. Dehydroepiandrosterone (DHEA) is a steroid hormone precursor correlated with reproductive success in other species, but has not been well studied in the polar bear. The purpose of the present study was to characterize the longitudinal excretion of DHEAS, the sulfated form of DHEA, from zoo-housed polar bears using a validated enzyme immunoassay. Lyophilized fecal samples from parturient females (n = 10), breeding non-parturient females (n = 11), a non-breeding adult female, a juvenile female, and a breeding adult male were investigated. Five of the breeding non-parturient females had been previously contracepted, while six were never contracepted. DHEAS concentrations were closely associated with testosterone concentrations (p < 0.05, rho > 0.57) for all reproductive statuses. Breeding females exhibited statistically significant (p < 0.05) increases in DHEAS concentration on or near breeding dates, which were not observed outside of the breeding season, or in the non-breeding or juvenile animals. Breeding non-parturient females exhibited higher median and baseline DHEAS concentrations than parturient females over the course of the breeding season. Previously contracepted (PC) breeding non-parturient females also exhibited higher season-long median and baseline DHEAS concentrations than non-previously (NPC) contracepted breeding non-parturient females. These findings suggest that DHEA is related to estrus or ovulation in the polar bear, that there is an optimal DHEA concentration window, and concentrations exceeding that threshold may be associated with reproductive dysfunction.
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Affiliation(s)
- Monica Brandhuber
- University of Alaska Fairbanks, College of Fisheries and Ocean Sciences, Fisheries Dept., Juneau Center, 17101 Pt. Lena Loop Road, Juneau, AK 99801, USA.
| | - Shannon Atkinson
- University of Alaska Fairbanks, College of Fisheries and Ocean Sciences, Fisheries Dept., Juneau Center, 17101 Pt. Lena Loop Road, Juneau, AK 99801, USA.
| | - Curry Cunningham
- University of Alaska Fairbanks, College of Fisheries and Ocean Sciences, Fisheries Dept., Juneau Center, 17101 Pt. Lena Loop Road, Juneau, AK 99801, USA.
| | - Terri Roth
- Center for Conservation and Research of Endangered Wildlife (CREW), Cincinnati Zoo and Botanical Garden, 3400 Vine Street, Cincinnati, OH 45220, USA.
| | - Erin Curry
- Center for Conservation and Research of Endangered Wildlife (CREW), Cincinnati Zoo and Botanical Garden, 3400 Vine Street, Cincinnati, OH 45220, USA.
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5
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Cerini F, Childs DZ, Clements CF. A predictive timeline of wildlife population collapse. Nat Ecol Evol 2023; 7:320-331. [PMID: 36702859 DOI: 10.1038/s41559-023-01985-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 01/06/2023] [Indexed: 01/27/2023]
Abstract
Contemporary rates of biodiversity decline emphasize the need for reliable ecological forecasting, but current methods vary in their ability to predict the declines of real-world populations. Acknowledging that stressor effects start at the individual level, and that it is the sum of these individual-level effects that drives populations to collapse, shifts the focus of predictive ecology away from using predominantly abundance data. Doing so opens new opportunities to develop predictive frameworks that utilize increasingly available multi-dimensional data, which have previously been overlooked for ecological forecasting. Here, we propose that stressed populations will exhibit a predictable sequence of observable changes through time: changes in individuals' behaviour will occur as the first sign of increasing stress, followed by changes in fitness-related morphological traits, shifts in the dynamics (for example, birth rates) of populations and finally abundance declines. We discuss how monitoring the sequential appearance of these signals may allow us to discern whether a population is increasingly at risk of collapse, or is adapting in the face of environmental change, providing a conceptual framework to develop new forecasting methods that combine multi-dimensional (for example, behaviour, morphology, life history and abundance) data.
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Affiliation(s)
- Francesco Cerini
- School of Biological Sciences, University of Bristol, Bristol, UK.
| | - Dylan Z Childs
- School of Biosciences, University of Sheffield, Sheffield, UK
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Kimmel K, Clark M, Tilman D. Impact of multiple small and persistent threats on extinction risk. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2022; 36:e13901. [PMID: 35212024 PMCID: PMC9790556 DOI: 10.1111/cobi.13901] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 02/01/2022] [Accepted: 02/09/2022] [Indexed: 06/14/2023]
Abstract
Many species may face multiple distinct and persistent drivers of extinction risk, yet theoretical and empirical studies tend to focus on the single largest driver. This means that existing approaches potentially underestimate and mischaracterize future risks to biodiversity. We synthesized existing knowledge on how multiple drivers of extinction can interact to influence a species' overall extinction probability in a probabilistic model of extinction risk that incorporated the impacts of multiple drivers of extinction risk, their interactions, and their accumulative effects through time. We then used this model framework to explore how different threats, interactions between them, and time trends may affect a species' overall extinction probability. Multiple small threats together had potential to pose a large cumulative extinction risk; for example, 10 individual threats posed a 1% extinction risk each and cumulatively posed a 9.7% total extinction risk. Interactions among drivers resulted in escalated risk in some cases, and persistent threats with a small (1%) extinction risk each decade ultimately posed large extinction risk over 100 (9.6% total extinction risk) to 200 years (18.2% total extinction risk). By estimating long-term extinction risk posed by several different factors and their interactions, this approach provides a framework to identify drivers of extinction risk that could be proactively targeted to help prevent species currently of least concern from becoming threatened with extinction.
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Affiliation(s)
- Kaitlin Kimmel
- Department of Earth and Planetary SciencesJohns Hopkins UniversityBaltimoreMarylandUSA
| | - Michael Clark
- Nuffield Department of Population HealthUniversity of OxfordOxfordUK
- Oxford Martin SchoolUniversity of OxfordOxfordUK
- Department of ZoologyUniversity of OxfordOxfordUK
- Interdisciplinary Centre for Conservation ScienceUniversity of OxfordOxfordUK
| | - David Tilman
- Ecology, Evolution and Behavior DepartmentUniversity of MinnesotaSt. PaulMinnesotaUSA
- Bren School of Environmental Science and ManagementUniversity of California, Santa BarbaraSanta BarbaraCaliforniaUSA
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7
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Applying novel connectivity networks to wood turtle populations to provide comprehensive conservation management strategies for species at risk. PLoS One 2022; 17:e0271797. [PMID: 35960725 PMCID: PMC9374220 DOI: 10.1371/journal.pone.0271797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 07/07/2022] [Indexed: 11/25/2022] Open
Abstract
Genetic diversity within and among populations is frequently used in prioritization processes to rank populations based on their vulnerability or distinctiveness, however, connectivity and gene flow are rarely considered within these frameworks. Using a wood turtle (Glyptemys insculpta) population graph, we introduce BRIDES as a new tool to evaluate populations for conservation purpose without focusing solely on individual nodes. BRIDES characterizes different types of shortest paths among the nodes of a subgraph and compares the shortest paths among the same nodes in a complete network. The main objectives of this study were to (1) introduce a BRIDES selection process to assist conservation biologists in the prioritization of populations, and (2) use different centrality indices and node removal statistics to compare BRIDES results and assess gene flow among wood turtle populations. We constructed six population subgraphs and used a stepwise selection algorithm to choose the optimal number of additional nodes, representing different populations, required to maximize network connectivity under different weighting schemes. Our results demonstrate the robustness of the BRIDES selection process for a given scenario, while inconsistencies were observed among node-based metrics. Results showed repeated selection of certain wood turtle populations, which could have not been predicted following only genetic diversity and distinctiveness estimation, node-based metrics and node removal analysis. Contrary to centrality measures focusing on static networks, BRIDES allowed for the analysis of evolving networks. To our knowledge, this study is the first to apply graph theory for turtle conservation genetics. We show that population graphs can reveal complex gene flow dynamics and population resiliency to local extinction. As such, BRIDES offers an interesting complement to node-based metrics and node removal to better understand the global processes at play when addressing population prioritization frameworks.
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8
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Leins JA, Grimm V, Drechsler M. Large-scale PVA modeling of insects in cultivated grasslands: The role of dispersal in mitigating the effects of management schedules under climate change. Ecol Evol 2022; 12:e9063. [PMID: 35845365 PMCID: PMC9272070 DOI: 10.1002/ece3.9063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 05/27/2022] [Accepted: 06/08/2022] [Indexed: 11/17/2022] Open
Abstract
In many species, dispersal is decisive for survival in a changing climate. Simulation models for population dynamics under climate change thus need to account for this factor. Moreover, large numbers of species inhabiting agricultural landscapes are subject to disturbances induced by human land use. We included dispersal in the HiLEG model that we previously developed to study the interaction between climate change and agricultural land use in single populations. Here, the model was parameterized for the large marsh grasshopper (LMG) in cultivated grasslands of North Germany to analyze (1) the species development and dispersal success depending on the severity of climate change in subregions, (2) the additional effect of grassland cover on dispersal success, and (3) the role of dispersal in compensating for detrimental grassland mowing. Our model simulated population dynamics in 60-year periods (2020-2079) on a fine temporal (daily) and high spatial (250 × 250 m2) scale in 107 subregions, altogether encompassing a range of different grassland cover, climate change projections, and mowing schedules. We show that climate change alone would allow the LMG to thrive and expand, while grassland cover played a minor role. Some mowing schedules that were harmful to the LMG nevertheless allowed the species to moderately expand its range. Especially under minor climate change, in many subregions dispersal allowed for mowing early in the year, which is economically beneficial for farmers. More severe climate change could facilitate LMG expansion to uninhabited regions but would require suitable mowing schedules along the path. These insights can be transferred to other species, given that the LMG is considered a representative of grassland communities. For more specific predictions on the dynamics of other species affected by climate change and land use, the publicly available HiLEG model can be easily adapted to the characteristics of their life cycle.
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Affiliation(s)
- Johannes A. Leins
- Department of Ecological ModellingHelmholtz Centre for Environmental Research – UFZLeipzigGermany
| | - Volker Grimm
- Department of Ecological ModellingHelmholtz Centre for Environmental Research – UFZLeipzigGermany
- Plant Ecology and Nature ConservationUniversity of PotsdamPotsdamGermany
| | - Martin Drechsler
- Department of Ecological ModellingHelmholtz Centre for Environmental Research – UFZLeipzigGermany
- Brandenburg University of Technology Cottbus‐SenftenbergCottbusGermany
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Ngo HN, Nguyen HQ, Tran HM, Phan TQ, Tran TT, Gewis :R, Rödder D, Nguyen TQ, Ziegler T. Living under the risk of extinction: population status and conservation needs assessment of a micro–endemic tiger gecko in Vietnam. ANIMAL BIODIVERSITY AND CONSERVATION 2022. [DOI: 10.32800/abc.2022.45.0175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Human impact is considered the major threat to the global decline of biodiversity, especially for threatened endemic species in karst ecosystems. Studies assessing a species' demography based on temporal and spatial indicators of population size, density and structure are expected to evaluate the level of impact of threats and are therefore becoming increasingly important for species conservation efforts. Goniurosaurus huuliensis, an endemic species in Vietnam, is one of the most threatened reptiles in the world. This karst–adapted species is classified by the IUCN Red List as Critically Endangered and listed under CITES Appendix II due to habitat loss and over–exploitation for the international pet trade. Here we provide the first evaluation of the population status of G. huuliensis. We applied a 'capture mark–recapture' method to estimate the population size and identify the population density and structure. The total population size was estimated to comprise a maximum of 1,447 individuals in integrated suitable habitats, possibly reaching up to 2,855 individuals exclusively in karst habitats within the total extension of occurrence. This is exceedingly lower than the threshold for a minimum viable population. Furthermore, G. huuliensis is documented to occur in extremely small mean population densities of only 6.4 indiv./km and 2.5 indiv./km/day along the surveyed transects. Based on the demographic information, the ongoing severe human impact (e.g. wildlife exploitation and limestone quarrying) is driving G. huuliensis to the brink of extinction. In situ conservation measures are therefore urgently required. We recommend that in-situ actions should be increased, and a plan should be developed to establish a species and habitat conservation area for G. huuliensis.
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Affiliation(s)
- H. N. Ngo
- Institute of Genome Research, Vietnam Academy of Science and Technology, Hanoi, Vietnam
| | - H. Q. Nguyen
- Vietnam National Museum of Nature, Vietnam Academy of Science and Technology, Hanoi, Vietnam
| | - H. M. Tran
- Institute of Ecology and Biological Resources, Vietnam Academy of Science and Technology, Hanoi , Vietnam
| | - T. Q. Phan
- Institute of Ecology and Biological Resources, Vietnam Academy of Science and Technology, Hanoi, Vietnam
| | - T. T. Tran
- Vinh Phuc College, Vinh Phuc Province, Vietnam
| | | | | | - T. Q. Nguyen
- University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi , Vietnam
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Horswill C, Miller JAO, Wood MJ. Impact assessments of wind farms on seabird populations that overlook existing drivers of demographic change should be treated with caution. CONSERVATION SCIENCE AND PRACTICE 2022. [DOI: 10.1111/csp2.12644] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Affiliation(s)
- Catharine Horswill
- ZSL Institute of Zoology London UK
- Centre for Biodiversity and Environmental Research, Department of Genetics, Evolution and Environment University College London London UK
- Department of Zoology University of Cambridge Cambridge UK
| | | | - Matt J. Wood
- School of Natural and Social Sciences University of Gloucestershire Cheltenham UK
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11
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Cervantes F, Martins M, Simmons RE. Population viability assessment of an endangered raptor using detection/non-detection data reveals susceptibility to anthropogenic impacts. ROYAL SOCIETY OPEN SCIENCE 2022; 9:220043. [PMID: 35223069 PMCID: PMC8864359 DOI: 10.1098/rsos.220043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 02/01/2022] [Indexed: 06/14/2023]
Abstract
As the demand for carbon-neutral energy sources increases, so does the need to understand the impacts that these technologies have on the environment. Here, we assess the potential consequences of additional mortality on an Endangered raptor recently exposed to wind farms for the first time, the Black Harrier Circus maurus, one of the world's rarest harriers. We conduct a population viability assessment using a Bayesian model integrating life-history information and annual reporting rates from detection/non-detection surveys from the South African Bird Atlas Project. Our model estimates a global population of approximately 1300 birds currently declining at 2.3% per year, and one that could collapse in under 100 years, if an average of three to five adult birds are killed annually. This level of mortality may soon exist, given the current rate of fatalities and the number of wind farms planned within the species' distribution. In addition, we find that the population is sensitive to changes in climate. Our results highlight the critical need for appropriate placement, and adaptive management of wind farms and other infrastructure causing harrier mortality. We also show how detection/non-detection data may be used to infer population dynamics and viability, when population counts are unavailable.
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Affiliation(s)
- Francisco Cervantes
- Centre for Statistics in Ecology, Environment and Conservation, University of Cape Town, Rondebosch 7701, Cape Town, South Africa
- FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch 7701, Cape Town, South Africa
| | | | - Robert E. Simmons
- FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch 7701, Cape Town, South Africa
- Birds and Bats Unlimited Cape Town, South Africa
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12
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Etterson MA, Ankley GT. Endogenous Lifecycle Models for Chemical Risk Assessment. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:15596-15608. [PMID: 34748315 PMCID: PMC9195053 DOI: 10.1021/acs.est.1c04791] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Despite over 50 years of research on the use of population models in chemical risk assessment, their practical utility has remained elusive. A novel application and interpretation of ecotoxicological models, Endogenous Lifecycle Models (ELM), is proposed that offers some of the benefits sought from population models, at much lower cost of design, parametrization, and verification. ELMs capture the endogenous lifecycle processes of growth, development, survival, and reproduction and integrate these to estimate and predict expected fitness. Two measures of fitness are proposed as natural model predictions in the context of chemical risk assessment, lifetime reproductive success, and the expected annual propagation of genetic descendants, including self (intrinsic fitness). Six characteristics of the ELM approach are reviewed and illustrated with two ELM examples, the first for a general passerine lifecycle and the second for bald eagle (Haliaeetus leucocephalus). Throughout, the focus is on development of robust qualitative model predictions that depend as little as possible on specific parameter values. Thus, ELMs sacrifice precision to optimize generality in understanding the effects of chemicals across the diversity of avian lifecycles. Notably, the ELM approach integrates naturally with the adverse outcome pathway framework; this integration can be employed as a midtier risk assessment tool when lower tier analyses suggest potential risk.
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Affiliation(s)
- Matthew A Etterson
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, Duluth, Minnesota 55804, United States
| | - Gerald T Ankley
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, Duluth, Minnesota 55804, United States
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Ruiz DM, Tinker MT, Tershy BR, Zilliacus KM, Croll DA. Using meta-population models to guide conservation action. Glob Ecol Conserv 2021. [DOI: 10.1016/j.gecco.2021.e01644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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14
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James TD, Salguero-Gómez R, Jones OR, Childs DZ, Beckerman AP. Bridging gaps in demographic analysis with phylogenetic imputation. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2021; 35:1210-1221. [PMID: 33068013 DOI: 10.1111/cobi.13658] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 09/10/2020] [Accepted: 10/08/2020] [Indexed: 06/11/2023]
Abstract
Phylogenetically informed imputation methods have rarely been applied to estimate missing values in demographic data but may be a powerful tool for reconstructing vital rates of survival, maturation, and fecundity for species of conservation concern. Imputed vital rates could be used to parameterize demographic models to explore how populations respond when vital rates are perturbed. We used standardized vital rate estimates for 50 bird species to assess the use of phylogenetic imputation to fill gaps in demographic data. We calculated imputation accuracy for vital rates of focal species excluded from the data set either singly or in combination and with and without phylogeny, body mass, and life-history trait data. We used imputed vital rates to calculate demographic metrics, including generation time, to validate the use of imputation in demographic analyses. Covariance among vital rates and other trait data provided a strong basis to guide imputation of missing vital rates in birds, even in the absence of phylogenetic information. Mean NRMSE for null and phylogenetic models differed by <0.01 except when no vital rates were available or for vital rates with high phylogenetic signal (Pagel's λ > 0.8). In these cases, including body mass and life-history trait data compensated for lack of phylogenetic information: mean normalized root mean square error (NRMSE) for null and phylogenetic models differed by <0.01 for adult survival and <0.04 for maturation rate. Estimates of demographic metrics were sensitive to the accuracy of imputed vital rates. For example, mean error in generation time doubled in response to inaccurate estimates of maturation time. Accurate demographic data and metrics, such as generation time, are needed to inform conservation planning processes, for example through International Union for Conservation of Nature Red List assessments and population viability analysis. Imputed vital rates could be useful in this context but, as for any estimated model parameters, awareness of the sensitivities of demographic model outputs to the imputed vital rates is essential.
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Affiliation(s)
- Tamora D James
- Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, U.K
| | - Roberto Salguero-Gómez
- Department of Zoology, University of Oxford, Zoology Research and Administration Building, 11a Mansfield Rd, Oxford, OX1 3SZ, U.K
| | - Owen R Jones
- Interdisciplinary Centre on Population Dynamics (CPop), Department of Biology, University of Southern Denmark, Campusvej 55, 5230 Odense M, Odense, Denmark
| | - Dylan Z Childs
- Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, U.K
| | - Andrew P Beckerman
- Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield, S10 2TN, U.K
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15
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Rayner K, Lohr CA, Garretson S, Speldewinde P. Two species, one island: Retrospective analysis of threatened fauna translocations with divergent outcomes. PLoS One 2021; 16:e0253962. [PMID: 34252101 PMCID: PMC8274872 DOI: 10.1371/journal.pone.0253962] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Accepted: 06/16/2021] [Indexed: 11/23/2022] Open
Abstract
Translocations are globally a popular tool used with the intention of improving threatened species conservation and re-establishing ecosystem function. While practitioners strive for successful outcomes the failure rate of translocations continues to be high. We demonstrate how predictive modelling can contribute to more informed decision making and hence potentially improve the success rate of translocation programs. Two species, the Djoongari (Shark Bay mouse) Pseudomys fieldi and the golden bandicoot Isoodon auratus barrowensis, were introduced independently to Doole Island in the Exmouth Gulf of Western Australia. We used population viability analysis to critique the outcomes of these translocations and provide an example of how this tool can be incorporated with expert knowledge to predict likely outcomes of translocations. Djoongari did not establish on the island after seven translocations over nine years, while golden bandicoots established a population after just one release event. Retrospective population viability analysis (of data that was unavailable prior to the translocations) predicted and clarified the reasons behind the outcomes of both translocations. Golden bandicoots have considerably higher demographic plasticity than Djoongari, which were never likely to establish on the island. We conclude that the failure of the Djoongari translocation was due to interactions between sparse habitat, native predators and cyclonic storm surges, whereas golden bandicoots have demonstrated habitat flexibility and an ability to recover from multiple natural disasters. As a result we (1) remind conservation planners of the importance of quantifying likely refuges and habitat availability at release sites, (2) suggest practitioners consider how different threats (including natural disasters) may interact at potential release sites and (3) advocate for the incorporation of predictive modelling during the planning stages of translocations, particularly for conservation introductions where no precedent exists for the species’ survival at a particular location.
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Affiliation(s)
- Kelly Rayner
- Biodiversity and Conservation Science Division, Western Australia Department of Biodiversity, Conservation and Attractions, Perth, Western Australia, Australia
- * E-mail:
| | - Cheryl A. Lohr
- Biodiversity and Conservation Science Division, Western Australia Department of Biodiversity, Conservation and Attractions, Perth, Western Australia, Australia
| | - Sean Garretson
- Biodiversity and Conservation Science Division, Western Australia Department of Biodiversity, Conservation and Attractions, Perth, Western Australia, Australia
| | - Peter Speldewinde
- Centre of Excellence in Natural Resource Management, The University of Western Australia, Perth, Western Australia, Australia
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16
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Eichenwald AJ, Reed JM. An Expanded Framework for Community Viability Analysis. Bioscience 2021. [DOI: 10.1093/biosci/biab034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Community viability analysis (CVA) has been put forth as an analogue for population viability analysis (PVA), an accepted conservation tool for evaluating species-specific threat and management scenarios. The original proposal recommended that CVAs examine resistance-based questions. PVAs, however, are broadly applicable to multiple types of viability questions, suggesting that the original CVA definition may be too narrow. In the present article, we advance an expanded framework in which CVA includes any analysis assessing the status, threats, or management options of an ecological community. We discuss viability questions that can be investigated with CVA. We group those inquiries into categories of resistance, resilience, and persistence, and provide case studies for each. Finally, we broadly present the steps in a CVA.
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Affiliation(s)
- Adam J Eichenwald
- PhD candidate, Tufts University, Medford, Massachusetts, United States
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17
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Tremblay RL, Tyre AJ, Pérez ME, Ackerman JD. Population projections from holey matrices: Using prior information to estimate rare transition events. Ecol Modell 2021. [DOI: 10.1016/j.ecolmodel.2021.109526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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18
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Leins JA, Banitz T, Grimm V, Drechsler M. High-resolution PVA along large environmental gradients to model the combined effects of climate change and land use timing: lessons from the large marsh grasshopper. Ecol Modell 2021. [DOI: 10.1016/j.ecolmodel.2020.109355] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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19
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Morgan JW, McCarthy MA, Willocks E. Does intraspecific variation in demography have implications for fire management of an obligate‐seeder shrub across its geographic range? AUSTRAL ECOL 2020. [DOI: 10.1111/aec.12981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- John W. Morgan
- Department of Ecology, Environment and Evolution La Trobe University Bundoora Victoria3083Australia
- Research Centre for Future Landscapes La Trobe University Bundoora VictoriaAustralia
| | - Michael A. McCarthy
- School of BioSciences The University of Melbourne Parkville VictoriaAustralia
| | - Emily Willocks
- Department of Ecology, Environment and Evolution La Trobe University Bundoora Victoria3083Australia
- Department of Environment, Land, Water and Planning East Melbourne Victoria Australia
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20
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Brooks GC, Gorman TA, Jiao Y, Haas CA. Reconciling larval and adult sampling methods to model growth across life-stages. PLoS One 2020; 15:e0237737. [PMID: 32822355 PMCID: PMC7442236 DOI: 10.1371/journal.pone.0237737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 07/31/2020] [Indexed: 11/29/2022] Open
Abstract
Individual growth rates are intrinsically related to survival and lifetime reproductive success and hence, are key determinants of population growth. Efforts to quantify age-size relationships are hampered by difficulties in aging individuals in wild populations. In addition, species with complex life-histories often show distinct shifts in growth that cannot be readily accommodated by traditional modelling techniques. Amphibians are often characterized by rapid larval growth, cessation of growth prior to metamorphosis, and resumption of growth in the adult stage. Compounding issues of non-linear growth, amphibian monitoring programs typically sample larval and adult populations using dissimilar methods. Here we present the first multistage growth model that combines disparate data collected across life-history stages. We model the growth of the endangered Reticulated Flatwoods Salamander, Ambystoma bishopi, in a Bayesian framework, that accounts for unknown ages, individual heterogeneity, and reconciles dip-net and drift fence sampling designs. Flatwoods salamanders achieve 60% of growth in the first 3 months of life but can survive for up to 13 years as a terrestrial adult. We find evidence for marked variability in growth rate, the timing and age at metamorphosis, and maximum size, within populations. Average size of metamorphs in a given year appeared strongly dependent on hydroperiod, and differed by >10mm across years with successful recruitment. In contrast, variation in the sizes of emerging metamorphs appeared relatively constant across years. An understanding of growth will contribute to the development of population viability analyses for flatwoods salamanders, will guide management actions, and will ultimately aid the recovery of the species. Our model formulation has broad applicability to amphibians, and likely any stage-structured organism in which homogenous data cannot be collected across life-stages. The tendency to ignore stage-structure or omit non-conforming data in growth analyses can no longer be afforded given the high stakes of management decisions, particularly for endangered or at-risk populations.
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Affiliation(s)
- George C. Brooks
- Department of Fish and Wildlife Conservation, Virginia Tech, Blacksburg, Virginia, United States of America
- * E-mail:
| | - Thomas A. Gorman
- Department of Fish and Wildlife Conservation, Virginia Tech, Blacksburg, Virginia, United States of America
| | - Yan Jiao
- Department of Fish and Wildlife Conservation, Virginia Tech, Blacksburg, Virginia, United States of America
| | - Carola A. Haas
- Department of Fish and Wildlife Conservation, Virginia Tech, Blacksburg, Virginia, United States of America
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21
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He C, DU J, Zhu D, Zhang L. Population viability analysis of small population: a case study for Asian elephant in China. Integr Zool 2020; 15:350-362. [PMID: 32246885 DOI: 10.1111/1749-4877.12432] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Small populations are at risk of extinction from deterministic and stochastic factors. Less than 250 Asian elephants (Elephas maximus) remain in China, and are distributed in a few isolated areas; yet, population viability analyses of this endangered population have not been conducted. Here, the current genetic status of the Pu'Er-Mengyang Asian elephant populations in China was analyzed, and the risk of extinction was predicted over the next 500 years. Factors affecting the viability of this population were determined through simulations. The genetic diversity of the population was very low (mean allele number: 3.1; expected heterozygosity: 0.463), even though a recent population bottleneck was not detected. The effective population size was approximately 24.1 adult elephants. Enough adult breeding individuals exist to maintain population viability. VORTEX simulation model showed that this population would not go extinct in the next 500 years. However, illegal poaching and harvesting could negatively affect population size. A sensitivity analysis showed that the mean stochastic growth rate of the study population is sensitive to sex ratio, number of breeding females, mortality of females of different age classes, carrying capacity, and lethal equivalents. Based on our results, we suggest that action should be taken to alleviate inbreeding and any further loss of genetic diversity, by connecting fragmented elephant habitat or by translocating individual elephants. In addition, human-elephant conflict should be mitigated using various modern approaches, including crop guarding techniques, and by encouraging farmers to switch to crops and income sources not vulnerable to elephant raids.
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Affiliation(s)
- Changhuan He
- College of Life Sciences, Beijing Normal University, Beijing, China
| | - Jiaojiao DU
- College of Life Sciences, Beijing Normal University, Beijing, China
| | - Di Zhu
- College of Life Sciences, Beijing Normal University, Beijing, China
| | - Li Zhang
- College of Life Sciences, Beijing Normal University, Beijing, China
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22
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Jackson J, Childs DZ, Mar KU, Htut W, Lummaa V. Long-term trends in wild-capture and population dynamics point to an uncertain future for captive elephants. Proc Biol Sci 2020; 286:20182810. [PMID: 30900534 DOI: 10.1098/rspb.2018.2810] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Maintaining sustainable populations in captivity without supplementation through wild-capture is a major challenge in conservation that zoos and aquaria are working towards. However, the capture of wild animals continues for many purposes where conservation is not the primary focus. Wild-capture hinders long-term conservation goals by reducing remaining wild populations, but the direct and long-term indirect consequences of wild-capture for captive population viability are rarely addressed using longitudinal data. We explored the implications of changes in wild-capture on population dynamics in captivity over 54 years using a multi-generational studbook of working Asian elephants ( Elephas maximus) from Myanmar, the largest remaining captive elephant population. Here we show that population growth and birth rates declined between 1960 and 2014 with declines in wild-capture. Importantly, wild-caught females had reduced birth rates and a higher mortality risk. However, despite the disadvantages of wild-capture, the population may not be sustainable without it, with immediate declines owing to an unstable age-structure that may last for 50 years. Our results highlight the need to assess the long-term demographic consequences of wild-capture to ensure the sustainability of captive and wild populations as species are increasingly managed and conserved in altered or novel environments.
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Affiliation(s)
- John Jackson
- 1 Department of Animal and Plant Sciences, University of Sheffield , Sheffield S10 2TN , UK
| | - Dylan Z Childs
- 1 Department of Animal and Plant Sciences, University of Sheffield , Sheffield S10 2TN , UK
| | - Khyne U Mar
- 2 Department of Biology, University of Turku , 20500 Turku , Finland
| | - Win Htut
- 3 Myanma Timber Enterprise, Ministry of Natural Resources and Environment Conservation, Gyogone Forest Compound , Bayint Naung Road, Insein Township, Yangon , Myanmar
| | - Virpi Lummaa
- 2 Department of Biology, University of Turku , 20500 Turku , Finland
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23
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Fryxell JM, Avgar T, Liu B, Baker JA, Rodgers AR, Shuter J, Thompson ID, Reid DEB, Kittle AM, Mosser A, Newmaster SG, Nudds TD, Street GM, Brown GS, Patterson B. Anthropogenic Disturbance and Population Viability of Woodland Caribou in Ontario. J Wildl Manage 2020. [DOI: 10.1002/jwmg.21829] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- John M. Fryxell
- Department of Integrative BiologyUniversity of Guelph 50 Stone Road E., Guelph Ontario N1G 2W1 Canada
| | - Tal Avgar
- Department of Integrative BiologyUniversity of Guelph 50 Stone Road E., Guelph Ontario N1G 2W1 Canada
| | - Boyan Liu
- Department of Integrative BiologyUniversity of Guelph 50 Stone Road E., Guelph Ontario N1G 2W1 Canada
| | - James A. Baker
- Ontario Ministry of Natural Resources and ForestryWildlife Research and Monitoring Section 300 Water Street, Peterborough Ontario K9J 8M5 Canada
| | - Arthur R. Rodgers
- Ontario Ministry of Natural Resources and ForestryCentre for Northern Forest Ecosystem Research 435 James Street Thunder‐Bay Ontario P7E 2VE Canada
| | - Jennifer Shuter
- Ontario Ministry of Natural Resources and ForestryCentre for Northern Forest Ecosystem Research 435 James Street Thunder‐Bay Ontario P7E 2VE Canada
| | - Ian D. Thompson
- Canadian Forest Service 1219 Queen Street East, Sault Ste. Marie Ontario P6A 2E5 Canada
| | - Douglas E. B. Reid
- Ontario Ministry of Natural Resources and ForestryCentre for Northern Forest Ecosystem Research 435 James Street Thunder‐Bay Ontario P7E 2VE Canada
| | - Andrew M. Kittle
- Department of Integrative BiologyUniversity of Guelph 50 Stone Road E., Guelph Ontario N1G 2W1 Canada
| | - Anna Mosser
- Department of Integrative BiologyUniversity of Guelph 50 Stone Road E., Guelph Ontario N1G 2W1 Canada
| | - Steven G. Newmaster
- Department of Integrative BiologyUniversity of Guelph 50 Stone Road E., Guelph Ontario N1G 2W1 Canada
| | - Tom D. Nudds
- Department of Integrative BiologyUniversity of Guelph 50 Stone Road E., Guelph Ontario N1G 2W1 Canada
| | - Garrett M. Street
- Department of Integrative BiologyUniversity of Guelph 50 Stone Road E., Guelph Ontario N1G 2W1 Canada
| | - Glen S. Brown
- Ontario Ministry of Natural Resources and ForestryWildlife Research and Monitoring Section 300 Water Street, Peterborough Ontario K9J 8M5 Canada
| | - Brent Patterson
- Ontario Ministry of Natural Resources and ForestryWildlife Research and Monitoring Section 300 Water Street, Peterborough Ontario K9J 8M5 Canada
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24
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Chaudhary V, Oli MK. A critical appraisal of population viability analysis. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2020; 34:26-40. [PMID: 31435956 DOI: 10.1111/cobi.13414] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 05/06/2019] [Accepted: 06/04/2019] [Indexed: 06/10/2023]
Abstract
Population viability analysis (PVA) is useful in management of imperiled species. Applications range from research design, threat assessment, and development of management frameworks. Given the importance of PVAs, it is essential that they be rigorous and adhere to widely accepted guidelines; however, the quality of published PVAs is rarely assessed. We evaluated the quality of 160 PVAs of 144 species of birds and mammals published in peer-reviewed journals from 1990 to 2017. We hypothesized that PVA quality would be lower with generic programs than with custom-built programs; be higher for those developed for imperiled species; change over time; and be higher for those published in journals with high impact factors (IFs). Each included study was evaluated based on answers to an evaluation framework containing 32 questions reflecting whether and to what extent the PVA study adhered to published PVA guidelines or contained important PVA components. All measures of PVA quality were generally lower for studies based on generic programs. Conservation status of the species did not affect any measure of PVA quality, but PVAs published in high IF journals were of higher quality. Quality generally declined over time, suggesting the quantitative literacy of PVA practitioners has not increased over time or that PVAs developed by unskilled users are being published in peer-reviewed journals. Only 18.1% of studies were of high quality (score >75%), which is troubling because poor-quality PVAs could misinform conservation decisions. We call for increased scrutiny of PVAs by journal editors and reviewers. Our evaluation framework can be used for this purpose. Because poor-quality PVAs continue to be published, we recommend caution while using PVA results in conservation decision making without thoroughly assessing the PVA quality.
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Affiliation(s)
- Vratika Chaudhary
- Department of Wildlife Ecology and Conservation, Newins-Zeigler Hall, University of Florida, Gainesville, FL, 32611, U.S.A
| | - Madan K Oli
- Department of Wildlife Ecology and Conservation, Newins-Zeigler Hall, University of Florida, Gainesville, FL, 32611, U.S.A
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25
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Lintermans M, Geyle HM, Beatty S, Brown C, Ebner BC, Freeman R, Hammer MP, Humphreys WF, Kennard MJ, Kern P, Martin K, Morgan DL, Raadik TA, Unmack PJ, Wager R, Woinarski JCZ, Garnett ST. Big trouble for little fish: identifying Australian freshwater fishes in imminent risk of extinction. ACTA ACUST UNITED AC 2020. [DOI: 10.1071/pc19053] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Globally, freshwater fishes are declining at an alarming rate. Despite much evidence of catastrophic declines, few Australian species are listed as threatened under national legislation. We aim to help redress this by identifying the Australian freshwater fishes that are in the most immediate risk of extinction. For 22 freshwater fishes (identified as highly threatened by experts), we used structured expert elicitation to estimate the probability of extinction in the next ~20 years, and to identify key threats and priority management needs. All but one of the 22 species are small (<150mm total length), 12 have been formally described only in the last decade, with seven awaiting description. Over 90% of these species were assessed to have a >50% probability of extinction in the next ~20 years. Collectively, the biggest factor contributing to the likelihood of extinction of the freshwater fishes considered is that they occur in small (distributions ≤44km2), geographically isolated populations, and are threatened by a mix of processes (particularly alien fishes and climate change). Nineteen of these species are unlisted on national legislation, so legislative drivers for recovery actions are largely absent. Research has provided strong direction on how to manage ~35% of known threats to the species considered, and, of these, ~36% of threats have some management underway (although virtually none are at the stage where intervention is no longer required). Increased resourcing, management intervention and social attitudinal change is urgently needed to avert the impending extinction of Australia’s most imperilled freshwater fishes.
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26
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Sowińska-Świerkosz B, Kolejko M. Extinction risk to lake minnow (Eupallasella percnurus) due to habitat loss: Eastern Poland case study. ENVIRONMENTAL MONITORING AND ASSESSMENT 2019; 191:571. [PMID: 31420753 PMCID: PMC6697757 DOI: 10.1007/s10661-019-7731-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 07/30/2019] [Indexed: 06/10/2023]
Abstract
In Poland, lake minnow (Eupallasella percnurus Pall.) inhabit 160 sites, including 44 in the eastern part of the country. Their habitats are mainly small and shallow peat holes vulnerable to complete destruction due to being dried or overgrown. Such processes are regularly observed, with ~ 60% of sites having vanished since the 1950s. Therefore, this species is one of the most endangered fish species from the Cyprinidae family in Polish inland waters. A GIS approach was adopted to fully analyze their habitat loss. The habitat area was marked in four time periods (from the 1960s to 2018) in reference to 26 sites composed of 111 reservoirs and representing almost 60% of all those documented in Eastern Poland. On this basis, the rate at which the habitat will vanish and the predicted time when this will happen were calculated. The results showed that the mean vanishing rate oscillates between 1 and 2% of the area per year for 50% of the analyzed sites (N = 13). For three sites (11%), this value does not exceed 1% of each area per year and is higher than 2% for the rest of the sites (39%). The results indicate that if the process of overgrowing and shallowing is not stopped, 58% of the analyzed sites will disappear in the next 50 years (including 8 (31%) in the next 20 years). This trend may lead to a serious decline in the species population or even its extinction in the next decades. Passive protection has proven to be insufficient in preserving lake minnow habitats. Therefore, there is an urgent need to undertake decisive protection action, as proposed in this manuscript.
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Affiliation(s)
- Barbara Sowińska-Świerkosz
- Department of Hydrobiology and Protection of Ecosystems, University of Life Sciences in Lublin, Dobrzańskiego 37, 20-262 Lublin, Poland
| | - Marcin Kolejko
- PGW WP - State Water Holding Polish Waters, The Regional Water Management Authority in Lublin, Leszka Czarnego 3, 20-610 Lublin, Poland
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27
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Jones AT, Lavery SD, Le Port A, Wang YG, Blower D, Ovenden J. Sweepstakes reproductive success is absent in a New Zealand snapper (Chrysophrus auratus) population protected from fishing despite "tiny" N e /N ratios elsewhere. Mol Ecol 2019; 28:2986-2995. [PMID: 31087739 DOI: 10.1111/mec.15130] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 04/30/2019] [Accepted: 05/01/2019] [Indexed: 01/07/2023]
Abstract
A landmark study published in 2002 estimated a very small Ne /N ratio (around 10-5 ) in a population of pink snapper (Chrysophrys auratus, Forster, 1801) in the Hauraki Gulf in New Zealand. It epitomized the tiny Ne /N ratios (<10-3 ) reported in marine species due to the hypothesized operation of sweepstakes reproductive success (SRS). Here we re-evaluate the occurrence of SRS in marine species and the potential effect of fishing on the Ne /N ratio by studying the same species in the same region, but in a population that has been protected from fishing since 1975. We combine empirical, simulation and model-based approaches to estimate Ne (and Nb ) from genotypes of 1,044 adult fish and estimate N using recapture-probabilities. The estimated Ne /N ratio was much larger (0.33, SE: 0.14) than expected. The magnitude of estimates of population-wide variance in individual lifetime reproductive success (10-18) suggested that the sweepstakes effect was negligible in the study population. After evaluating factors that could explain the contrast between studies - experimental design, life history differences, environmental effects and the influence of exploitation on the Ne /N ratio - we conclude that the low Ne of the Hauraki Gulf population is associated with demographic instability in the harvested compared to the protected population despite circumstantial evidence that the 2002 study may have underestimated Ne . This study has broad implications for the prevailing view that reproductive success in the sea is largely driven by chance, and for genetic monitoring of populations using the Ne /N ratio and Nb .
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Affiliation(s)
- Andrew T Jones
- School of Mathematics and Physics, University of Queensland, Brisbane, Queensland, Australia
| | - Shane D Lavery
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.,Institute of Marine Science, University of Auckland, Auckland, New Zealand
| | - Agnès Le Port
- Institute of Marine Science, University of Auckland, Auckland, New Zealand.,Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Townsville, Queensland, Australia
| | - You-Gan Wang
- Science and Engineering Faculty, School of Mathematical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Dean Blower
- School of Biological Sciences, University of Queensland, Brisbane, Queensland, Australia.,Molecular Fisheries Laboratory and School of Biomedical Sciences, University of Queensland, Brisbane, Queensland, Australia
| | - Jennifer Ovenden
- Molecular Fisheries Laboratory and School of Biomedical Sciences, University of Queensland, Brisbane, Queensland, Australia
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28
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Estimating Sustainable Harvest Rates for European Hare (Lepus Europaeus) Populations. SUSTAINABILITY 2019. [DOI: 10.3390/su11102837] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Hunting quotas are used to manage populations of game species in order to ensure sustainable exploitation. However, unpredictable climatic events may interact with hunting. We established a population model for European hares (Lepus europaeus) in Lower Austria. We compared the sustainability of voluntary quotas used by hunters—which are derived from hare-specific guidelines—with the actual numbers of hares shot and our recommended quotas for hares, which have been derived from climate and population modeling. We used population modeling based on vital rates and densities to adjust our recommended quotas in order to achieve sustainable harvest. The survival of age classes 1 and 3 had the highest impact on the population growth rate. Population viability analysis showed that a recommended quota with a harvest rate of 10% was sustainable for population densities of 45 hares/km2, and that the threshold for hunting should be raised from 10 hares/km2 so that hare populations with <15 hares/km2 are not hunted. The recommended quota outperformed the voluntary hunting quota, since more hares could be harvested sustainably. Age Class 1 survival was strongly linked with weather: a single year with unfavorable weather conditions (low precipitation) negatively affected population densities. Game species, including the European hare, face increasingly frequent weather extremes due to climate change, so hunting quotas need to be sensitive to frequent population fluctuations.
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de Silva S, Leimgruber P. Demographic Tipping Points as Early Indicators of Vulnerability for Slow-Breeding Megafaunal Populations. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00171] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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García-Díaz P, Prowse TAA, Anderson DP, Lurgi M, Binny RN, Cassey P. A concise guide to developing and using quantitative models in conservation management. CONSERVATION SCIENCE AND PRACTICE 2019; 1:e11. [PMID: 31915752 PMCID: PMC6949132 DOI: 10.1002/csp2.11] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Quantitative models are powerful tools for informing conservation
management and decision-making. As applied modeling is increasingly used to
address conservation problems, guidelines are required to clarify the scope of
modeling applications and to facilitate the impact and acceptance of models by
practitioners. We identify three key roles for quantitative models in
conservation management: (a) to assess the extent of a conservation problem; (b)
to provide insights into the dynamics of complex social and ecological systems;
and, (c) to evaluate the efficacy of proposed conservation interventions. We
describe 10 recommendations to facilitate the acceptance of quantitative models
in conservation management, providing a basis for good practice to guide their
development and evaluation in conservation applications. We structure these
recommendations within four established phases of model construction, enabling
their integration within existing workflows: (a) design (two recommendations);
(b) specification (two); (c) evaluation (one); and (d) inference (five).
Quantitative modeling can support effective conservation management provided
that both managers and modelers understand and agree on the place for models in
conservation. Our concise review and recommendations will assist conservation
managers and modelers to collaborate in the development of quantitative models
that are fit-for-purpose, and to trust and use these models appropriately while
understanding key drivers of uncertainty.
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Affiliation(s)
| | - Thomas A A Prowse
- School of Mathematical Sciences, The University of Adelaide, North Terrace, South Australia, Australia
| | | | - Miguel Lurgi
- Centre for Biodiversity Theory and Modelling, Theoretical and Experimental Ecology Station, CNRS-Paul Sabatier University, Moulis, France
| | - Rachelle N Binny
- Manaaki Whenua - Landcare Research, Lincoln, New Zealand.,Te Pūnaha Matatini, Centre of Research Excellence for Complex Systems and Networks, Auckland, New Zealand
| | - Phillip Cassey
- School of Biological Sciences, The University of Adelaide, North Terrace, South Australia, Australia
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García‐Díaz P, Prowse TA, Anderson DP, Lurgi M, Binny RN, Cassey P. A concise guide to developing and using quantitative models in conservation management. CONSERVATION SCIENCE AND PRACTICE 2019. [DOI: 10.1111/csp2.11] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Affiliation(s)
| | - Thomas A.A. Prowse
- School of Mathematical SciencesThe University of Adelaide North Terrace South Australia Australia
| | | | - Miguel Lurgi
- Centre for Biodiversity Theory and Modelling, Theoretical and Experimental Ecology StationCNRS‐Paul Sabatier University Moulis France
| | - Rachelle N. Binny
- Manaaki Whenua ‐ Landcare Research Lincoln New Zealand
- Te Pūnaha MatatiniCentre of Research Excellence for Complex Systems and Networks Auckland New Zealand
| | - Phillip Cassey
- School of Biological SciencesThe University of Adelaide North Terrace South Australia Australia
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Cheney BJ, Thompson PM, Cordes LS. Increasing trends in fecundity and calf survival of bottlenose dolphins in a marine protected area. Sci Rep 2019; 9:1767. [PMID: 30741983 PMCID: PMC6370779 DOI: 10.1038/s41598-018-38278-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 12/21/2018] [Indexed: 11/09/2022] Open
Abstract
Estimates of temporal variation in demographic rates are critical for identifying drivers of population change and supporting conservation. However, for inconspicuous wide-ranging species, births may be missed and fecundity rates underestimated. We address this issue using photo-identification data and a novel robust design multistate model to investigate changes in bottlenose dolphin fecundity and calf survival. The model allows for uncertainty in breeding status, and seasonal effects. The best model estimated an increase in the proportion of females with newborn calves from 0.16 (95% CI = 0.11-0.24) in 2001 to 0.28 (95% CI = 0.22-0.36) in 2016. First year calf survival also increased over this period from 0.78 (95% CI = 0.53-0.92) to 0.93 (95% CI = 0.82-0.98). Second year calf survival remained lower, but also showed an increase from 0.32 (95% CI = 0.19-0.48) to 0.55 (95% CI = 0.44-0.65). Females with newborn calves had a slightly higher mortality than those with older calves, but further work is required to evaluate potential costs of reproduction. This study presents a rare example of empirical evidence of a positive trend in reproduction and survival for a cetacean population using a Marine Protected Area.
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Affiliation(s)
- Barbara J Cheney
- University of Aberdeen, Institute of Biological and Environmental Science, Lighthouse Field Station, Cromarty, IV11 8YL, UK.
| | - Paul M Thompson
- University of Aberdeen, Institute of Biological and Environmental Science, Lighthouse Field Station, Cromarty, IV11 8YL, UK
| | - Line S Cordes
- Bangor University, School of Ocean Sciences, Menai Bridge, LL59 5AB, UK
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Wheeler ME, Barzen JA, Crimmins SM, Van Deelen TR. Effects of territorial status and life history on Sandhill Crane ( Antigone canadensis) population dynamics in south-central Wisconsin, USA. CAN J ZOOL 2019. [DOI: 10.1139/cjz-2018-0135] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Population growth rate in long-lived bird species is often most sensitive to changes in adult survival. Sandhill Cranes (Antigone canadensis (Linnaeus, 1758)) have long life spans, small broods, and delayed first reproduction. Only territorial adult Sandhill Cranes participate in breeding, and territory acquisition reflects the interplay between the availability of suitable territories and the variation in mortality of adult birds occupying those territories. We estimated vital rates of a population at equilibrium using long-term resightings data (2000–2014; n = 451 marked individuals) in a multistate mark–resight model and used a stage-structured projection matrix to assess how strongly territorial adult survival affects population growth rate. Elasticity analysis indicated territorial birds surviving and retaining territories had a 2.58 times greater impact on population growth compared with the next most important transition rate (survival of nonterritorial adults remaining nonterritorial). Knowing how changes in vital rates of various stage classes will differentially impact population growth rate allows for targeted management actions including encouraging growth in recovering populations, assessing opportunity for recreational harvest, or maintaining populations at a desired level. This study also highlights the value of collecting demographic data for all population segments, from which one can derive reproductive output or growth rate.
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Affiliation(s)
- Michael E. Wheeler
- Nelson Institute for Environmental Studies, University of Wisconsin–Madison, 1630 Linden Drive, Madison, WI 53706, USA
| | - Jeb A. Barzen
- International Crane Foundation, E-11376 Shady Lane Road, Baraboo, WI 53913, USA
| | - Shawn M. Crimmins
- College of Natural Resources, University of Wisconsin–Stevens Point, 800 Reserve Street, Stevens Point, WI 54481, USA
| | - Timothy R. Van Deelen
- Department of Forest and Wildlife Ecology, University of Wisconsin–Madison, 1630 Linden Drive, Madison, WI 53706, USA
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Kelly E, Phillips B. How many and when? Optimising targeted gene flow for a step change in the environment. Ecol Lett 2019; 22:447-457. [PMID: 30618109 DOI: 10.1111/ele.13201] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 09/19/2018] [Accepted: 11/23/2018] [Indexed: 12/25/2022]
Abstract
Targeted gene flow is an emerging conservation strategy that involves introducing individuals with particular traits to places where these traits are of benefit. One obvious application is to adapt a recipient population to a known threat, but questions remain as to how best to achieve this. Here, we vary timing and size of the introduction to maximise our objective - survival of the recipient population's genome. We explore a generic population model as well as a specific example - the northern quoll, an Australian marsupial predator threatened by the toxic cane toad. We reveal a trade-off between preserving the recipient genome and reducing population extinction risk, but key management levers can often optimise this so that nearly 100% of the recipient population's genome is preserved. Any action was better than none but the size of the benefit was sensitive to outbreeding depression, recombination rate, and the timing and size of the introduction.
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Affiliation(s)
- Ella Kelly
- School of Biosciences, The University of Melbourne, Parkville, 3010, Australia
| | - Ben Phillips
- School of Biosciences, The University of Melbourne, Parkville, 3010, Australia
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Crain BJ, Tremblay RL, Ferguson JM. Sheltered from the storm? Population viability analysis of a rare endemic under periodic catastrophe regimes. POPUL ECOL 2018. [DOI: 10.1002/1438-390x.1002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Benjamin J. Crain
- Department of Biology; University of Puerto Rico-Río Piedras; San Juan Puerto Rico
| | - Raymond L. Tremblay
- Department of Biology; University of Puerto Rico-Río Piedras; San Juan Puerto Rico
- Center for Applied Tropical Ecology and Conservation, Department of Biology; University of Puerto Rico-Río Piedras; San Juan Puerto Rico
| | - Jake M. Ferguson
- NIMBioS; University of Tennessee-Knoxville; Knoxville Tennessee
- Fisheries, Wildlife & Conservation Biology; University of Minnesota; St. Paul Minnesota
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Tchabovsky A, Savinetskaya L, Surkova E. Breeding versus survival: proximate causes of abrupt population decline under environmental change in a desert rodent, the midday gerbil (Meriones meridianus). Integr Zool 2018; 14:366-375. [PMID: 30585409 DOI: 10.1111/1749-4877.12372] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Studying abrupt ecological shifts under gradual environmental change caused, in particular, by human activity is important for understanding the fundamental aspects and underlying mechanisms of ecological resilience. One of the rare well-documented examples of an abrupt ecological shift is the delayed step transition of the population of a desert rodent, the midday gerbil (Meriones meridianus), from high-abundance (1994-2002) to low-abundance (2003-2017) regimes. This was in response to landscape transformation from desert to steppe caused by the drastic reduction of livestock in the rangelands of southern Russia after the collapse of the USSR in the early 1990s. In this study, we tested whether demographic parameters were correlated with the observed abrupt downward population shift. We found that reproductive activity (the percentage of breeding females, the number of litters, fecundity and the number of young recruited per female) showed no trend over time and did not differ between periods of high and low abundance. In contrast, the adult sex ratio (SR = males: females) decreased significantly with time and was as much as twice more female-biased for the low-abundance population regime. However, SR was not related to any reproductive parameter, including the percentage of breeding females. We conclude that proximate reasons for an abrupt population decline in M. meridianus are not associated with the changes in breeding patterns or mate limitation caused by the Allee effect but relate to the increased mortality as a result of the desert landscape being fragmented by steppezation. The mortality is expected to be higher for males as the mobile and dispersing sex.
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Affiliation(s)
- Andrey Tchabovsky
- Laboratory for Population Ecology, A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia
| | - Ludmila Savinetskaya
- Laboratory for Population Ecology, A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia
| | - Elena Surkova
- Laboratory for Population Ecology, A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia
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37
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Lacy RC. Lessons from 30 years of population viability analysis of wildlife populations. Zoo Biol 2018; 38:67-77. [PMID: 30585658 DOI: 10.1002/zoo.21468] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 11/14/2018] [Accepted: 12/04/2018] [Indexed: 12/16/2022]
Abstract
Population viability analysis (PVA) has been used for three decades to assess threats and evaluate conservation options for wildlife populations. What has been learned from PVA on in situ populations are valuable lessons also for assessing and managing viability and sustainability of ex situ populations. The dynamics of individual populations are unpredictable, due to limited knowledge about important factors, variability in the environment, and the probabilistic nature of demographic events. PVA considers such uncertainty within simulations that generate the distribution of likely fates for a population; management of ex situ populations should also take into consideration the uncertainty in our data and in the trajectories of populations. The processes affecting wildlife populations interact, with feedbacks often leading to amplified threats to viability; projections of ex situ populations should include such feedbacks to allow for management that foresees and responds to the cumulative and synergistic threats. PVA is useful for evaluating conservation options only if the goals for each population and measures of success are first clearly identified; similarly, for ex situ populations to contribute maximally to species conservation, the purposes for the population and definitions of sustainability in terms of acceptable risk must be documented. PVA requires a lot of data, knowledge of many processes affecting the populations, modeling expertize, and understanding of management goals and constraints. Therefore, to be useful in guiding conservation it must be a collaborative, trans-disciplinary, and social process. PVA can help integrate management of in situ and ex situ populations within comprehensive species conservation plans.
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38
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Davis RA, Lohr CA, Dale Roberts J. Frog survival and population viability in an agricultural landscape with a drying climate. POPUL ECOL 2018. [DOI: 10.1002/1438-390x.1001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Robert A. Davis
- School of Science; Edith Cowan University; Joondalup Western Australia Australia
- School of Biological Sciences; University of Western Australia; Perth Western Australia Australia
| | - Cheryl A. Lohr
- Department of Biodiversity, Conservation and Attractions; Science and Conservation Division; Perth Western Australia Australia
| | - J. Dale Roberts
- School of Biological Sciences; University of Western Australia; Perth Western Australia Australia
- Centre of Excellence in Natural Resource Management; University of Western Australia; Perth Western Australia Australia
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van Poorten BT, Beck M, Herborg LM. Turning population viability analysis on its head: using stochastic models to evaluate invasive species control strategies. Biol Invasions 2018. [DOI: 10.1007/s10530-018-1890-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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40
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Hernández-Camacho CJ, Trites AW. Population viability analysis of Guadalupe fur seals Arctocephalus townsendi. ENDANGER SPECIES RES 2018. [DOI: 10.3354/esr00925] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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41
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Bradke DR, Bailey RL, Bartman JF, Campa H, Hileman ET, Krueger C, Kudla N, Lee YM, Thacker AJ, Moore JA. Sensitivity Analysis Using Site-Specific Demographic Parameters to Guide Research and Management of Threatened Eastern Massasaugas. COPEIA 2018. [DOI: 10.1643/ot-18-059] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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42
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Abstract
The use of human mediated translocations has been an increasing component of many species recovery initiatives, including for numerous imperiled Lepidopteran species. Despite the identified need for this ex situ strategy, few such programs are conducted in a scientifically repeatable way, are executed with a structured decision-making process, are well documented throughout, or are documented only in gray literature. The International Union for Conservation of Nature’s Guidelines for Reintroductions and Other Conservation Translocations are an important tool for conservation practitioners to help implement comprehensive translocation planning. These generalized guidelines are intended to be applicable to all taxa. Though there is a growing body of literature and supplementary guidelines for many vertebrate classes, other proposed standards fail to capture the specific biology of many invertebrate groups, like Lepidoptera. Here, we present a targeted list of detailed recommendations that are appropriate for Lepidopteran translocation programs to expand on the broad and tested guidelines developed by the IUCN. We assert that the increased standardization and repeatability among Lepidopteran translocations will improve the conservation outcomes.
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43
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Gervasi V, Ciucci P. Demographic projections of the Apennine brown bear population Ursus arctos marsicanus (Mammalia: Ursidae) under alternative management scenarios. THE EUROPEAN ZOOLOGICAL JOURNAL 2018. [DOI: 10.1080/24750263.2018.1478003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022] Open
Affiliation(s)
- V. Gervasi
- Department of Biology and Biotechnologies, La Sapienza University of Rome, Italy
| | - P. Ciucci
- Department of Biology and Biotechnologies, La Sapienza University of Rome, Italy
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Thompson GG, Maguire LA, Regan TJ. Evaluation of Two Approaches to Defining Extinction Risk under the U.S. Endangered Species Act. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2018; 38:1009-1035. [PMID: 29314154 DOI: 10.1111/risa.12927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 07/07/2017] [Accepted: 09/08/2017] [Indexed: 06/07/2023]
Abstract
The predominant definition of extinction risk in conservation biology involves evaluating the cumulative distribution function (CDF) of extinction time at a particular point (the "time horizon"). Using the principles of decision theory, this article develops an alternative definition of extinction risk as the expected loss (EL) to society resulting from eventual extinction of a species. Distinct roles are identified for time preference and risk aversion. Ranges of tentative values for the parameters of the two approaches are proposed, and the performances of the two approaches are compared and contrasted for a small set of real-world species with published extinction time distributions and a large set of hypothetical extinction time distributions. Potential issues with each approach are evaluated, and the EL approach is recommended as the better of the two. The CDF approach suffers from the fact that extinctions that occur at any time before the specified time horizon are weighted equally, while extinctions that occur beyond the specified time horizon receive no weight at all. It also suffers from the fact that the time horizon does not correspond to any natural phenomenon, and so is impossible to specify nonarbitrarily; yet the results can depend critically on the specified value. In contrast, the EL approach has the advantage of weighting extinction time continuously, with no artificial time horizon, and the parameters of the approach (the rates of time preference and risk aversion) do correspond to natural phenomena, and so can be specified nonarbitrarily.
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Affiliation(s)
- Grant G Thompson
- Resource Ecology and Fisheries Management Division, U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Alaska Fisheries Science Center, Seattle, WA, USA
| | - Lynn A Maguire
- Nicholas School of the Environment and Earth Sciences, Duke University, Durham, NC, USA
| | - Tracey J Regan
- Protected Services Division, U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Southwest Fisheries Science Center, La Jolla, CA, USA
- The Arthur Rylah Institute for Environmental Research, The Department of Environment, Land, Water and Planning, Heidelberg, Victoria, Australia
- School of Biosciences, The University of Melbourne, Victoria, Australia
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Smith JH, King T, Campbell C, Cheyne SM, Nijman V. Modelling Population Viability of Three Independent Javan Gibbon (Hylobates moloch) Populations on Java, Indonesia. Folia Primatol (Basel) 2018; 88:507-522. [PMID: 29393266 DOI: 10.1159/000484559] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 10/25/2017] [Indexed: 11/19/2022]
Abstract
Population viability analysis is a predictive procedure that uses a combination of different modelling approaches to estimate species vulnerability to extinction. Javan gibbons (Hylobates moloch) are vulnerable to local extinction primarily due to loss of habitat and hunting for the illegal pet trade. Using the modelling software VORTEX, we assessed the status of Javan gibbons in 3 areas (Ujung Kulon National Park, Halimun-Salak National Park, and Dieng Mountains) which hold over half of the remaining estimated number of gibbons on Java. Ujung Kulon and Halimun-Salak are long-time protected areas, whereas Dieng Mountains remain unprotected. For each area, we calculated the probability of extinction over a 100-year time period by testing different area-specific scenarios (e.g., hunting, deforestation, and increase in carrying capacity). Our modelling suggests each of the populations has a high chance of becoming extinct within the next 100 years if hunting and deforestation persist. If these threats are eliminated, the model shows each of the populations are large enough to persist in the long term whilst maintaining high levels of current genetic diversity. We conclude that specific actions should be implemented to develop more inclusive conservation management practices, especially improving awareness regarding the illegal wildlife trade and increased protection of wild populations and their habitats.
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Whitehead T, Vernes K, Goosem M, Abell SE. Invasive predators represent the greatest extinction threat to the endangered northern bettong (Bettongia tropica). WILDLIFE RESEARCH 2018. [DOI: 10.1071/wr16103] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Context Identification of key threats to endangered species is vital for devising effective management strategies, but may be hindered when relevant data is limited. A population viability approach may overcome this problem. Aims We aimed to determine the population viability of endangered northern bettongs (Bettongia tropica) in north-eastern Australia. We also assessed the key threats to the population resilience and how the population viability responds to increases in mortality rates and changes in fire and drought frequency. Methods Using population viability analysis (PVA) we modelled survival probability of B. tropica populations under likely scenarios, including: (1) increased predation; (2) changes in drought and fire frequency predicted with anthropogenic climate change; and (3) synergistic effects of predation, fire and drought. Key results Population viability models suggest that populations are highly vulnerable to increases in predation by feral cats (Felis catus), and potentially red fox (Vulpes vulpes) should they colonise the area, as juvenile mortality is the main age class driving population viability. If B. tropica become more vulnerable to predators during post-fire vegetation recovery, more frequent fires could exacerbate effects of low-level cat predation. In contrast, it was predicted that populations would be resilient to the greater frequency of droughts expected as a result of climate change, with high probabilities of extinctions only predicted under the unprecedented and unlikely scenario of four drought years in 10. However, since drought and fire are interlinked, the impacts of predation could be more severe with climate change should predation and fire interact to increase B. tropica mortality risk. Conclusion Like other Potoroids, B. tropica appear highly vulnerable to predation by introduced mammalian predators such as feral cats. Implications Managers need information allowing them to recognise scenarios when populations are most vulnerable to potential threats, such as drought, fire and predation. PVA modelling can assess scenarios and allow pro-active management based on predicted responses rather than requiring collection of extensive field data before management actions. Our analysis suggests that assessing and controlling predator populations and thereby minimising predation, particularly of juveniles, should assist in maintaining stability of populations of the northern bettong.
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Geyle HM, Woinarski JCZ, Baker GB, Dickman CR, Dutson G, Fisher DO, Ford H, Holdsworth M, Jones ME, Kutt A, Legge S, Leiper I, Loyn R, Murphy BP, Menkhorst P, Reside AE, Ritchie EG, Roberts FE, Tingley R, Garnett ST. Quantifying extinction risk and forecasting the number of impending Australian bird and mammal extinctions. ACTA ACUST UNITED AC 2018. [DOI: 10.1071/pc18006] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A critical step towards reducing the incidence of extinction is to identify and rank the species at highest risk, while implementing protective measures to reduce the risk of extinction to such species. Existing global processes provide a graded categorisation of extinction risk. Here we seek to extend and complement those processes to focus more narrowly on the likelihood of extinction of the most imperilled Australian birds and mammals. We considered an extension of existing IUCN and NatureServe criteria, and used expert elicitation to rank the extinction risk to the most imperilled species, assuming current management. On the basis of these assessments, and using two additional approaches, we estimated the number of extinctions likely to occur in the next 20 years. The estimates of extinction risk derived from our tighter IUCN categorisations, NatureServe assessments and expert elicitation were poorly correlated, with little agreement among methods for which species were most in danger – highlighting the importance of integrating multiple approaches when considering extinction risk. Mapped distributions of the 20 most imperilled birds reveal that most are endemic to islands or occur in southern Australia. The 20 most imperilled mammals occur mostly in northern and central Australia. While there were some differences in the forecasted number of extinctions in the next 20 years among methods, all three approaches predict further species loss. Overall, we estimate that another seven Australian mammals and 10 Australian birds will be extinct by 2038 unless management improves.
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48
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Meyer-Gutbrod EL, Greene CH. Uncertain recovery of the North Atlantic right whale in a changing ocean. GLOBAL CHANGE BIOLOGY 2018; 24:455-464. [PMID: 29084379 DOI: 10.1111/gcb.13929] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 09/25/2017] [Accepted: 09/27/2017] [Indexed: 05/06/2023]
Abstract
Human activities have placed populations of many endangered species at risk and mitigation efforts typically focus on reducing anthropogenic sources of mortality. However, failing to recognize the additional role of environmental factors in regulating birth and mortality rates can lead to erroneous demographic analyses and conclusions. The North Atlantic right whale population is currently the focus of conservation efforts aimed at reducing mortality rates associated with ship strikes and entanglement in fishing gear. Consistent monitoring of the population since 1980 has revealed evidence that climate-associated changes in prey availability have played an important role in the population's recovery. The considerable interdecadal differences observed in population growth coincide with remote Arctic and North Atlantic oceanographic processes that link to the Gulf of Maine ecosystem. Here, we build capture-recapture models to quantify the role of prey availability on right whale demographic transitional probabilities and use a corresponding demographic model to project population growth rates into the next century. Contrary to previous predictions, the right whale population is projected to recover in the future as long as prey availability and mortality rates remain within the ranges observed during 1980-2012. However, recent events indicate a northward range shift in right whale prey, potentially resulting in decreased prey availability and/or an expansion of right whale habitat into unprotected waters. An annual increase in the number of whale deaths comparable to that observed during the summer 2017 mass mortality event may cause a decline to extinction even under conditions of normal prey availability. This study highlights the importance of understanding the oceanographic context for observed population changes when evaluating the efficacy of conservation management plans for endangered marine species.
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Affiliation(s)
- Erin L Meyer-Gutbrod
- Marine Science Institute, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Charles H Greene
- Ocean Ecosystems and Resources Program, Earth and Atmospheric Sciences, Cornell University, Ithaca, NY, USA
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49
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Demographic Analysis of Imperiled Eastern Massasaugas (Sistrurus catenatus catenatus). J HERPETOL 2017. [DOI: 10.1670/15-058] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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50
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Field CR, Bayard TS, Gjerdrum C, Hill JM, Meiman S, Elphick CS. High-resolution tide projections reveal extinction threshold in response to sea-level rise. GLOBAL CHANGE BIOLOGY 2017; 23:2058-2070. [PMID: 27684043 DOI: 10.1111/gcb.13519] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 08/25/2016] [Indexed: 06/06/2023]
Abstract
Sea-level rise will affect coastal species worldwide, but models that aim to predict these effects are typically based on simple measures of sea level that do not capture its inherent complexity, especially variation over timescales shorter than 1 year. Coastal species might be most affected, however, by floods that exceed a critical threshold. The frequency and duration of such floods may be more important to population dynamics than mean measures of sea level. In particular, the potential for changes in the frequency and duration of flooding events to result in nonlinear population responses or biological thresholds merits further research, but may require that models incorporate greater resolution in sea level than is typically used. We created population simulations for a threatened songbird, the saltmarsh sparrow (Ammodramus caudacutus), in a region where sea level is predictable with high accuracy and precision. We show that incorporating the timing of semidiurnal high tide events throughout the breeding season, including how this timing is affected by mean sea-level rise, predicts a reproductive threshold that is likely to cause a rapid demographic shift. This shift is likely to threaten the persistence of saltmarsh sparrows beyond 2060 and could cause extinction as soon as 2035. Neither extinction date nor the population trajectory was sensitive to the emissions scenarios underlying sea-level projections, as most of the population decline occurred before scenarios diverge. Our results suggest that the variation and complexity of climate-driven variables could be important for understanding the potential responses of coastal species to sea-level rise, especially for species that rely on coastal areas for reproduction.
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Affiliation(s)
- Christopher R Field
- Department of Ecology and Evolutionary Biology, Center for Conservation and Biodiversity, and Institute of Biological Risk, University of Connecticut, 75 N. Eagleville Road, Unit 3043, Storrs, CT, 06269-3043, USA
| | - Trina S Bayard
- Audubon Washington, 5902 Lake Washington Blvd. S., Seattle, WA, 98118, USA
| | - Carina Gjerdrum
- Environment and Climate Change Canada, 45 Alderney Drive, Dartmouth, NS, B2Y 2N6, Canada
| | - Jason M Hill
- Vermont Center for Ecostudies, PO Box 420, Norwich, VT, 05055, USA
| | - Susan Meiman
- Institute for Wildlife Studies, 2327 Kettner Boulevard, San Diego, CA 92101, USA
| | - Chris S Elphick
- Department of Ecology and Evolutionary Biology, Center for Conservation and Biodiversity, and Institute of Biological Risk, University of Connecticut, 75 N. Eagleville Road, Unit 3043, Storrs, CT, 06269-3043, USA
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