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Peters C, Geary M, Hosie C, Nelson H, Rusk B, Muir A. Non-invasive sampling reveals low mitochondrial genetic diversity for an island endemic species: The critically endangered Grenada Dove Leptotila wellsi. Ecol Evol 2023; 13:e10767. [PMID: 38020693 PMCID: PMC10667608 DOI: 10.1002/ece3.10767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/30/2023] [Accepted: 11/07/2023] [Indexed: 12/01/2023] Open
Abstract
As an island endemic with a decreasing population, the critically endangered Grenada Dove Leptotila wellsi is threatened by accelerated loss of genetic diversity resulting from ongoing habitat fragmentation. Small, threatened populations are difficult to sample directly but advances in molecular methods mean that non-invasive samples can be used. We performed the first assessment of genetic diversity of populations of Grenada Dove by (a) assessing mtDNA genetic diversity in the only two areas of occupancy on Grenada, (b) defining the number of haplotypes present at each site and (c) evaluating evidence of isolation between sites. We used non-invasively collected samples from two locations: Mt Hartman (n = 18) and Perseverance (n = 12). DNA extraction and PCR were used to amplify 1751 bps of mtDNA from two mitochondrial markers: NADH dehydrogenase 2 (ND2) and Cytochrome b (Cyt b). Haplotype diversity (h) of 0.4, a nucleotide diversity (π) of 0.00023 and two unique haplotypes were identified within the ND2 sequences; a single haplotype was identified within the Cyt b sequences. Of the two haplotypes identified, the most common haplotype (haplotype A = 73.9%) was observed at both sites and the other (haplotype B = 26.1%) was unique to Perseverance. Our results show low mitochondrial genetic diversity and clear evidence for genetically isolated populations. The Grenada Dove needs urgent conservation action, including habitat protection and potentially augmentation of gene flow by translocation in order to increase genetic resilience and diversity with the ultimate aim of securing the long-term survival of this critically endangered species.
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Affiliation(s)
- Catherine Peters
- Conservation Biology Research Group, Department of Biological SciencesUniversity of ChesterChesterUK
| | - Matthew Geary
- Conservation Biology Research Group, Department of Biological SciencesUniversity of ChesterChesterUK
| | - Charlotte Hosie
- Conservation Biology Research Group, Department of Biological SciencesUniversity of ChesterChesterUK
| | | | - Bonnie Rusk
- Grenada Dove Conservation ProgrammeSt GeorgesGrenada
| | - Anna Muir
- Conservation Biology Research Group, Department of Biological SciencesUniversity of ChesterChesterUK
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2
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Birand A, Cassey P, Ross JV, Russell JC, Thomas P, Prowse TAA. Gene drives for vertebrate pest control: realistic spatial modelling of eradication probabilities and times for island mouse populations. Mol Ecol 2022; 31:1907-1923. [PMID: 35073448 PMCID: PMC9303646 DOI: 10.1111/mec.16361] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 01/07/2022] [Accepted: 01/12/2022] [Indexed: 11/29/2022]
Abstract
Invasive alien species continue to threaten global biodiversity. CRISPR‐based gene drives, which can theoretically spread through populations despite imparting a fitness cost, could be used to suppress or eradicate pest populations. We develop an individual‐based, spatially explicit, stochastic model to simulate the ability of CRISPR‐based homing and X chromosome shredding drives to eradicate populations of invasive house mice (Mus muculus) from islands. Using the model, we explore the interactive effect of the efficiency of the drive constructs and the spatial ecology of the target population on the outcome of a gene‐drive release. We also consider the impact of polyandrous mating and sperm competition, which could compromise the efficacy of some gene‐drive strategies. Our results show that both drive strategies could be used to eradicate large populations of mice. Whereas parameters related to drive efficiency and demography strongly influence drive performance, we find that sperm competition following polyandrous mating is unlikely to impact the outcome of an eradication effort substantially. Assumptions regarding the spatial ecology of mice influenced the probability of and time required for eradication, with short‐range dispersal capacities and limited mate‐search areas producing ‘chase’ dynamics across the island characterized by cycles of local extinction and recolonization by mice. We also show that highly efficient drives are not always optimal, when dispersal and mate‐search capabilities are low. Rapid local population suppression around the introduction sites can cause loss of the gene drive before it can spread to the entire island. We conclude that, although the design of efficient gene drives is undoubtedly critical, accurate data on the spatial ecology of target species are critical for predicting the result of a gene‐drive release.
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Affiliation(s)
- Aysegul Birand
- Invasion Science and Wildlife Ecology Lab, School of Biological Sciences, The University of Adelaide, Adelaide, Australia
| | - Phillip Cassey
- Invasion Science and Wildlife Ecology Lab, School of Biological Sciences, The University of Adelaide, Adelaide, Australia
| | - Joshua V Ross
- School of Mathematical Sciences, The University of Adelaide, Adelaide, Australia
| | - James C Russell
- School of Biological Sciences, Department of Statistics, University of Auckland, Auckland, New Zealand
| | - Paul Thomas
- School of Medicine, Robinson Research Institute, The University of Adelaide, Adelaide, Australia.,South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Thomas A A Prowse
- Invasion Science and Wildlife Ecology Lab, School of Biological Sciences, The University of Adelaide, Adelaide, Australia
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3
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Mairal M, Chown SL, Shaw J, Chala D, Chau JH, Hui C, Kalwij JM, Münzbergová Z, Jansen van Vuuren B, Le Roux JJ. Human activity strongly influences genetic dynamics of the most widespread invasive plant in the sub-Antarctic. Mol Ecol 2021; 31:1649-1665. [PMID: 34181792 DOI: 10.1111/mec.16045] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 06/14/2021] [Accepted: 06/21/2021] [Indexed: 11/26/2022]
Abstract
The link between the successful establishment of alien species and propagule pressure is well-documented. Less known is how humans influence the post-introduction dynamics of invasive alien populations. The latter requires studying parallel invasions by the same species in habitats that are differently impacted by humans. We analysed microsatellite and genome size variation, and then compared the genetic diversity and structure of invasive Poa annua L. on two sub-Antarctic islands: human-occupied Marion Island and unoccupied Prince Edward Island. We also carried out niche modelling to map the potential distribution of the species on both islands. We found high levels of genetic diversity and evidence for extensive admixture between genetically distinct lineages of P. annua on Marion Island. By contrast, the Prince Edward Island populations showed low genetic diversity, no apparent admixture, and had smaller genomes. On both islands, high genetic diversity was apparent at human landing sites, and on Marion Island, also around human settlements, suggesting that these areas received multiple introductions and/or acted as initial introduction sites and secondary sources (bridgeheads) for invasive populations. More than 70 years of continuous human activity associated with a meteorological station on Marion Island led to a distribution of this species around human settlements and along footpaths, which facilitates ongoing gene flow among geographically separated populations. By contrast, this was not the case for Prince Edward Island, where P. annua populations showed high genetic structure. The high levels of genetic variation and admixture in P. annua facilitated by human activity, coupled with high habitat suitability on both islands, suggest that P. annua is likely to increase its distribution and abundance in the future.
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Affiliation(s)
- Mario Mairal
- Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa.,Departamento de Biodiversidad, Ecología y Evolución, Facultad de Ciencias Biológicas, Universidad Complutense de Madrid, Ciudad Universitaria, Madrid, Spain
| | - Steven L Chown
- Securing Antarctica's Environmental Future, School of Biological Sciences, Monash University, Victoria, Australia
| | - Justine Shaw
- School of Biological Sciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Desalegn Chala
- Natural History Museum, University of Oslo, Oslo, Norway
| | - John H Chau
- Centre for Ecological Genomics and Wildlife Conservation, Department of Zoology, University of Johannesburg, Auckland Park, South Africa
| | - Cang Hui
- Centre for Invasion Biology, Department of Mathematical Sciences, Stellenbosch University, Stellenbosch, South Africa.,Biodiversity Informatics Unit, African Institute for Mathematical Sciences, Cape Town, South Africa
| | - Jesse M Kalwij
- Centre for Ecological Genomics and Wildlife Conservation, Department of Zoology, University of Johannesburg, Auckland Park, South Africa.,Institute of Geography and Geoecology, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Zuzana Münzbergová
- Department of Botany, Charles University, Prague, Czech Republic.,Department of Population Ecology, Czech Academy of Science, Průhonice, Czech Republic
| | - Bettine Jansen van Vuuren
- Centre for Ecological Genomics and Wildlife Conservation, Department of Zoology, University of Johannesburg, Auckland Park, South Africa
| | - Johannes J Le Roux
- Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa.,Department of Biological Sciences, Macquarie University, Sydney, New South Wales, Australia
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Pliego-Sánchez JV, Blair C, Díaz de la Vega-Pérez AH, Jiménez-Arcos VH. The insular herpetofauna of Mexico: Composition, conservation, and biogeographic patterns. Ecol Evol 2021; 11:6579-6592. [PMID: 34141242 PMCID: PMC8207341 DOI: 10.1002/ece3.7513] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 02/25/2021] [Accepted: 03/12/2021] [Indexed: 12/02/2022] Open
Abstract
We compile a Mexican insular herpetofaunal checklist to estimate endemism, conservation status, island threats, net taxonomic turnover among six biogeographic provinces belonging to the Nearctic and Neotropical regions, and the relationships between island area and mainland distance versus species richness. We compile a checklist of insular herpetofaunal through performing a literature and collection review. We define the conservation status according to conservation Mexican law, the Red List of International Union for Conservation of Nature, and Environmental Vulnerability Scores. We determine threat percentages on islands according to the 11 major classes of threats to biodiversity. We estimate the net taxonomic turnover with beta diversity analysis between the Nearctic and Neotropical provinces. The Mexican insular herpetofauna is composed of 18 amphibian species, 204 species with 101 subspecies of reptiles, and 263 taxa in total. Endemism levels are 11.76% in amphibians, 53.57% in reptiles, and 27.91% being insular endemic taxa. Two conservation status systems classify the species at high extinction risk, while the remaining system suggests less concern. However, all systems indicate species lacking assessment. Human activities and exotic alien species are present on 60% of 131 islands. The taxonomic turnover value is high (0.89), with a clear herpetofaunal differentiation between the two biogeographic regions. The species-area and species-mainland distance relationships are positive. Insular herpetofauna faces a high percentage of threats, with the Neotropical provinces more heavily impacted. It is urgent to explore the remaining islands (3,079 islands) and better incorporate insular populations and species in ecological, evolutionary, and systematic studies. In the face of the biodiversity crisis, islands will play a leading role as a model to apply restoration and conservation strategies.
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Affiliation(s)
| | - Christopher Blair
- Department of Biological Sciences New York City College of Technology The City University of New York Brooklyn NY USA
- Biology PhD Program, Graduate Center New York NY USA
| | - Aníbal H Díaz de la Vega-Pérez
- Consejo Nacional de Ciencia y Tecnología-Centro Tlaxcala de Biología de la Conducta Universidad Autónoma de Tlaxcala Tlaxcala Mexico
| | - Víctor H Jiménez-Arcos
- Laboratorio de Herpetología Vivario FES Iztacala Universidad Nacional Autónoma de México Tlalnepantla Mexico
- Naturam Sequi AC Naucalpan Mexico Mexico
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Bombaci SP, Innes J, Kelly D, Flaherty V, Pejchar L. Excluding mammalian predators increases bird densities and seed dispersal in fenced ecosanctuaries. Ecology 2021; 102:e03340. [PMID: 33709447 DOI: 10.1002/ecy.3340] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 01/11/2021] [Indexed: 11/08/2022]
Abstract
Islands are epicenters of animal extinctions and population declines. These losses exacerbate biodiversity loss and disrupt ecological services in areas of high endemism. Island defaunation is primarily driven by invasive mammalian predators, and mammal eradications are reversing population declines for some island species. Invasive mammal eradications may also have the capacity to restore ecological interactions, along with the recovery of island fauna. Here we show that invasive mammal eradication in fenced ecosanctuaries results in higher rates of bird foraging on fruit, and higher bird-mediated seed dispersal, than in similar forests without mammal eradication. We further show that higher foraging and seed dispersal is related to higher densities of native bird species, after accounting for natural variation in fruit availability. For the many other systems globally that are under threat from invasive mammals, New Zealand's fenced ecosanctuary model offers a promising tool for restoring biodiversity and ecosystem services.
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Affiliation(s)
- Sara P Bombaci
- Department of Fish, Wildlife and Conservation Biology, Colorado State University, Fort Collins, Colorado, 80523, USA
| | - John Innes
- Manaaki Whenua, Landcare Research, Hamilton, New Zealand
| | - Dave Kelly
- Biological Sciences, University of Canterbury, Christchurch, 8140, New Zealand
| | - Victoria Flaherty
- College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, 43210, USA
| | - Liba Pejchar
- Department of Fish, Wildlife and Conservation Biology, Colorado State University, Fort Collins, Colorado, 80523, USA
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6
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Prowse TA, Adikusuma F, Cassey P, Thomas P, Ross JV. A Y-chromosome shredding gene drive for controlling pest vertebrate populations. eLife 2019; 8:41873. [PMID: 30767891 PMCID: PMC6398975 DOI: 10.7554/elife.41873] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 02/13/2019] [Indexed: 11/16/2022] Open
Abstract
Self-replicating gene drives that modify sex ratios or infer a fitness cost could be used to control populations of invasive alien species. The targeted deletion of Y sex chromosomes using CRISPR technology offers a new approach for sex bias that could be incorporated within gene-drive designs. We introduce a novel gene-drive strategy termed Y-CHromosome deletion using Orthogonal Programmable Endonucleases (Y-CHOPE), incorporating a programmable endonuclease that ‘shreds’ the Y chromosome, thereby converting XY males into fertile XO females. Firstly, we demonstrate that the CRISPR/Cas12a system can eliminate the Y chromosome in embryonic stem cells with high efficiency (c. 90%). Next, using stochastic, individual-based models of a pest mouse population, we show that a Y-shredding drive that progressively depletes the pool of XY males could effect population eradication through mate limitation. Our molecular and modeling data suggest that a Y-CHOPE gene drive could be a viable tool for vertebrate pest control.
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Affiliation(s)
- Thomas Aa Prowse
- School of Mathematical Sciences, The University of Adelaide, Adelaide, Australia
| | - Fatwa Adikusuma
- School of Medicine, The University of Adelaide, Adelaide, Australia.,South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Phillip Cassey
- The Centre for Applied Conservation Science, The University of Adelaide, Adelaide, Australia.,School of Biological Sciences, The University of Adelaide, Adelaide, Australia
| | - Paul Thomas
- School of Medicine, The University of Adelaide, Adelaide, Australia.,South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Joshua V Ross
- School of Mathematical Sciences, The University of Adelaide, Adelaide, Australia
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7
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Todd CM, Westcott DA, Rose K, Martin JM, Welbergen JA. Slow growth and delayed maturation in a Critically Endangered insular flying fox ( Pteropus natalis). J Mammal 2018; 99:1510-1521. [PMID: 30538341 PMCID: PMC6283735 DOI: 10.1093/jmammal/gyy110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 08/24/2018] [Indexed: 11/14/2022] Open
Abstract
Flying foxes (family Pteropodidae) have distinct life histories given their size, characterized by longevity, low reproductive output, and long gestation. However, they tend to decouple the age at which sexual maturity is reached from the age at which they reach adult dimensions. We examined growth, maturation, and reproduction in the Critically Endangered Christmas Island flying fox (Pteropus natalis) to determine the timing of sex-specific life cycle events and patterns of growth. We estimated that juvenile growth in forearm length and body mass increased at a mean rate of 0.029 ± 0.005 mm/day and 0.33 ± 0.07 g/day for both males and females alike. Using these growth rates, we determined that the birth of pups occurs between December and March, with young becoming volant between June and August. The age at maturation for P. natalis is one of the oldest among all bat species. Juvenile males began to mature 15 months after birth and reached maturity 27 months after birth. Females reached maturity 24 months after birth at a significantly smaller body mass (3.6%) and forearm length (1.4%) than males. Significant sexual dimorphism and bimaturation was observed, with juvenile males being 1.5% and adult males being 1.9% larger on average than females for skeletal dimensions only. Growth and maturation are even slower in P. natalis than in the few other Pteropus species studied to date. The slow growth and delayed maturation of P. natalis imply slower potential population growth rates, further complicating the recovery of this Critically Endangered single-island endemic.
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Affiliation(s)
- Christopher M Todd
- The Hawkesbury institute for the Environment, Western Sydney University, Richmond, New South Wales, Australia
| | - David A Westcott
- Commonwealth Scientific and Industrial Research Organisation (CSIRO), Land and Water, Maunds St. Atherton, Queensland, Australia
| | - Karrie Rose
- Taronga Conservation Society Australia, Australian Registry Wildlife Health, Mosman, New South Wales, Australia
| | - John M Martin
- Royal Botanic Gardens and Domain Trust, Mrs Macquaries Road, Sydney, New South Wales, Australia
| | - Justin A Welbergen
- The Hawkesbury institute for the Environment, Western Sydney University, Richmond, New South Wales, Australia
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Duron Q, Bourguet E, De Meringo H, Millon A, Vidal E. Invasive rats strengthen predation pressure on bird eggs in a South Pacific island rainforest. Curr Zool 2017; 63:583-590. [PMID: 29492018 PMCID: PMC5804218 DOI: 10.1093/cz/zox009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Accepted: 01/31/2017] [Indexed: 11/13/2022] Open
Abstract
Invasive rats (Rattus spp.) are known to have pervasive impacts on island birds, particularly on their nesting success. To conserve or restore bird populations, numerous invasive rat control or eradication projects are undertaken on islands worldwide. However, such projects represent a huge investment and the decision-making process requires proper assessment of rat impacts. Here, we assessed the influence of two sympatric invasive rats (Rattus rattus and R. exulans) on native bird eggs in a New Caledonian rainforest, using artificial bird-nest monitoring. A total of 178 artificial nests containing two eggs of three different sizes were placed either on the ground or 1.5 m high and monitored at the start of the birds' breeding season. Overall, 12.4% of the nests were depredated during the first 7 days. At site 1, where nests were monitored during 16 days, 41.8% of the nests were depredated. The main predator was the native crow Corvus moneduloides, responsible for 62.9% of the overall predation events. Rats were responsible for only 22.9% of the events, and ate only small and medium eggs at both heights. Our experiment suggests that in New Caledonia, predation pressure by rats strengthens overall bird-nest predation, adding to that by native predators. Experimental rat control operations may allow reduced predation pressure on nests as well as the recording of biodiversity responses after rat population reduction.
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Affiliation(s)
- Quiterie Duron
- Institut Méditerranéen de Biodiversité et d’Ecologie Marine et Continentale (IMBE) Aix Marseille Université, CNRS, IRD, Avignon Université, Centre IRD Nouméa - BP A5, 98848 Nouméa Cedex, Nouvelle-Calédonie, France
| | - Edouard Bourguet
- Institut Méditerranéen de Biodiversité et d’Ecologie Marine et Continentale (IMBE) Aix Marseille Université, CNRS, IRD, Avignon Université, Centre IRD Nouméa - BP A5, 98848 Nouméa Cedex, Nouvelle-Calédonie, France
| | - Hélène De Meringo
- Institut Méditerranéen de Biodiversité et d’Ecologie Marine et Continentale (IMBE) Aix Marseille Université, CNRS, IRD, Avignon Université, Technopôle Arbois-Méditerranée, Bât. Villemin – BP 80, F-13545 Aix-en-Provence cedex 04, France
| | - Alexandre Millon
- Institut Méditerranéen de Biodiversité et d’Ecologie Marine et Continentale (IMBE) Aix Marseille Université, CNRS, IRD, Avignon Université, Technopôle Arbois-Méditerranée, Bât. Villemin – BP 80, F-13545 Aix-en-Provence cedex 04, France
| | - Eric Vidal
- Institut Méditerranéen de Biodiversité et d’Ecologie Marine et Continentale (IMBE) Aix Marseille Université, CNRS, IRD, Avignon Université, Centre IRD Nouméa - BP A5, 98848 Nouméa Cedex, Nouvelle-Calédonie, France
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Prowse TAA, Cassey P, Ross JV, Pfitzner C, Wittmann TA, Thomas P. Dodging silver bullets: good CRISPR gene-drive design is critical for eradicating exotic vertebrates. Proc Biol Sci 2017; 284:20170799. [PMID: 28794219 PMCID: PMC5563802 DOI: 10.1098/rspb.2017.0799] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 07/03/2017] [Indexed: 01/08/2023] Open
Abstract
Self-replicating gene drives that can spread deleterious alleles through animal populations have been promoted as a much needed but controversial 'silver bullet' for controlling invasive alien species. Homing-based drives comprise an endonuclease and a guide RNA (gRNA) that are replicated during meiosis via homologous recombination. However, their efficacy for controlling wild populations is threatened by inherent polymorphic resistance and the creation of resistance alleles via non-homologous end-joining (NHEJ)-mediated DNA repair. We used stochastic individual-based models to identify realistic gene-drive strategies capable of eradicating vertebrate pest populations (mice, rats and rabbits) on islands. One popular strategy, a sex-reversing drive that converts heterozygous females into sterile males, failed to spread and required the ongoing deployment of gene-drive carriers to achieve eradication. Under alternative strategies, multiplexed gRNAs could overcome inherent polymorphic resistance and were required for eradication success even when the probability of NHEJ was low. Strategies causing homozygotic embryonic non-viability or homozygotic female sterility produced high probabilities of eradication and were robust to NHEJ-mediated deletion of the DNA sequence between multiplexed endonuclease recognition sites. The latter two strategies also purged the gene drive when eradication failed, therefore posing lower long-term risk should animals escape beyond target islands. Multiplexing gRNAs will be necessary if this technology is to be useful for insular extirpation attempts; however, precise knowledge of homing rates will be required to design low-risk gene drives with high probabilities of eradication success.
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Affiliation(s)
- Thomas A A Prowse
- School of Mathematical Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Phillip Cassey
- The Environment Institute and School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Joshua V Ross
- School of Mathematical Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Chandran Pfitzner
- The Environment Institute and School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Talia A Wittmann
- The Environment Institute and School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
| | - Paul Thomas
- The Environment Institute and School of Biological Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia
- The Robinson Research Institute, The University of Adelaide, Adelaide, South Australia 5005, Australia
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10
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Duron Q, Shiels AB, Vidal E. Control of invasive rats on islands and priorities for future action. Conserv Biol 2017; 31:761-771. [PMID: 27982493 DOI: 10.1111/cobi.12885] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Revised: 11/30/2016] [Accepted: 12/01/2016] [Indexed: 06/06/2023]
Abstract
Invasive rats are one of the world's most successful animal groups that cause native species extinctions and ecosystem change, particularly on islands. On large islands, rat eradication is often impossible and population control, defined as the local limitation of rat abundance, is now routinely performed on many of the world's islands as an alternative management tool. However, a synthesis of the motivations, techniques, costs, and outcomes of such rat-control projects is lacking. We reviewed the literature, searched relevant websites, and conducted a survey via a questionnaire to synthesize the available information on rat-control projects in island natural areas worldwide to improve rat management and native species conservation. Data were collected from 136 projects conducted over the last 40 years; most were located in Australasia (46%) and the tropical Pacific (25%) in forest ecosystems (65%) and coastal strands (22%). Most of the projects targeted Rattus rattus and most (82%) were aimed at protecting birds and endangered ecosystems. Poisoning (35%) and a combination of trapping and poisoning (42%) were the most common methods. Poisoning allows for treatment of larger areas, and poison projects generally last longer than trapping projects. Second-generation anticoagulants (mainly brodifacoum and bromadiolone) were used most often. The median annual cost for rat-control projects was US$17,262 or US$227/ha. Median project duration was 4 years. For 58% of the projects, rat population reduction was reported, and 51% of projects showed evidence of positive effects on biodiversity. Our data were from few countries, revealing the need to expand rat-control distribution especially in some biodiversity hotspots. Improvement in control methods is needed as is regular monitoring to assess short- and long-term effectiveness of rat-control.
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Affiliation(s)
- Quiterie Duron
- Institut Méditerranéen de Biodiversité et d'Écologie marine et continentale (IMBE), Aix-Marseille Université, UMR CNRS - IRD - UAPV, Centre IRD Nouméa - BP A5, 98848, Nouméa Cedex, New Caledonia
| | - Aaron B Shiels
- USDA, National Wildlife Research Center, 4101 LaPorte Avenue, Ft. Collins, CO, 80521, U.S.A
| | - Eric Vidal
- Institut Méditerranéen de Biodiversité et d'Écologie marine et continentale (IMBE), Aix-Marseille Université, UMR CNRS - IRD - UAPV, Centre IRD Nouméa - BP A5, 98848, Nouméa Cedex, New Caledonia
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11
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Velarde E, Ezcurra E, Horn MH, Patton RT. Warm oceanographic anomalies and fishing pressure drive seabird nesting north. Sci Adv 2015; 1:e1400210. [PMID: 26601193 PMCID: PMC4640602 DOI: 10.1126/sciadv.1400210] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 05/12/2015] [Indexed: 06/05/2023]
Abstract
Parallel studies of nesting colonies in Mexico and the United States show that Elegant Terns (Thalasseus elegans) have expanded from the Gulf of California Midriff Island Region into Southern California, but the expansion fluctuates from year to year. A strong inverse relationship between nesting pairs in three Southern California nesting areas [San Diego saltworks, Bolsa Chica Ecological Reserve, and Los Angeles Harbor (1991 to 2014)] and Isla Rasa in the Midriff (1980 to 2014) shows that terns migrate northward when confronting warm oceanographic anomalies (>1.0°C), which may decrease fish availability and hamper nesting success. Migration pulses are triggered by sea surface temperature anomalies localized in the Midriff and, secondarily, by reductions in the sardine population as a result of intensive fishing. This behavior is new; before year 2000, the terns stayed in the Midriff even when oceanographic conditions were adverse. Our results show that terns are responding dynamically to rapidly changing oceanographic conditions and fish availability by migrating 600 km northwest in search of more productive waters.
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Affiliation(s)
- Enriqueta Velarde
- Instituto de Ciencias Marinas y Pesquerías, Universidad Veracruzana, Hidalgo 617, Colonia Río Jamapa, Boca del Río, Veracruz 94290, Mexico
| | - Exequiel Ezcurra
- Department of Botany and Plant Sciences, University of California, Riverside, 900 University Avenue, Riverside, CA 92521, USA
| | - Michael H. Horn
- Department of Biological Science, California State University, Fullerton, Fullerton, CA 92834–6850, USA
| | - Robert T. Patton
- Avian Research Associates, 830 Orange Avenue, Suite K, Coronado, CA 92118, USA
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12
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Spatz DR, Newton KM, Heinz R, Tershy B, Holmes ND, Butchart SHM, Croll DA. The biogeography of globally threatened seabirds and island conservation opportunities. Conserv Biol 2014; 28:1282-1290. [PMID: 24661307 DOI: 10.1111/cobi.12279] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Accepted: 12/10/2013] [Indexed: 06/03/2023]
Abstract
Seabirds are the most threatened group of marine animals; 29% of species are at some risk of extinction. Significant threats to seabirds occur on islands where they breed, but in many cases, effective island conservation can mitigate these threats. To guide island-based seabird conservation actions, we identified all islands with extant or extirpated populations of the 98 globally threatened seabird species, as recognized on the International Union for Conservation of Nature Red List, and quantified the presence of threatening invasive species, protected areas, and human populations. We matched these results with island attributes to highlight feasible island conservation opportunities. We identified 1362 threatened breeding seabird populations on 968 islands. On 803 (83%) of these islands, we identified threatening invasive species (20%), incomplete protected area coverage (23%), or both (40%). Most islands with threatened seabirds are amenable to island-wide conservation action because they are small (57% were <1 km(2) ), uninhabited (74%), and occur in high- or middle-income countries (96%). Collectively these attributes make islands with threatened seabirds a rare opportunity for effective conservation at scale.
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Affiliation(s)
- Dena R Spatz
- Coastal Conservation Action Lab, Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, 95060, U.S.A
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13
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Courchamp F, Hoffmann BD, Russell JC, Leclerc C, Bellard C. Climate change, sea-level rise, and conservation: keeping island biodiversity afloat. Trends Ecol Evol 2014; 29:127-30. [PMID: 24486005 DOI: 10.1016/j.tree.2014.01.001] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 01/06/2014] [Accepted: 01/07/2014] [Indexed: 11/25/2022]
Abstract
Island conservation programs have been spectacularly successful over the past five decades, yet they generally do not account for impacts of climate change. Here, we argue that the full spectrum of climate change, especially sea-level rise and loss of suitable climatic conditions, should be rapidly integrated into island biodiversity research and management.
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Affiliation(s)
- Franck Courchamp
- Ecologie, Systématique et Evolution, UMR CNRS 8079, University of Paris Sud, Orsay Cedex 91405, France.
| | | | - James C Russell
- University of Auckland, School of Biological Sciences and Department of Statistics, Private Bag 92019, Auckland 1142, New Zealand
| | - Camille Leclerc
- Ecologie, Systématique et Evolution, UMR CNRS 8079, University of Paris Sud, Orsay Cedex 91405, France
| | - Céline Bellard
- Ecologie, Systématique et Evolution, UMR CNRS 8079, University of Paris Sud, Orsay Cedex 91405, France
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14
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SHEPPARD CRC, ATEWEBERHAN M, BOWEN BW, CARR P, CHEN CA, CLUBBE C, CRAIG MT, EBINGHAUS R, EBLE J, FITZSIMMONS N, GAITHER MR, GAN CH, GOLLOCK M, GUZMAN N, GRAHAM NAJ, HARRIS A, JONES R, KESHAVMURTHY S, KOLDEWEY H, LUNDIN CG, MORTIMER JA, OBURA D, PFEIFFER M, PRICE ARG, PURKIS S, RAINES P, READMAN JW, RIEGL B, ROGERS A, SCHLEYER M, SEAWARD MRD, SHEPPARD ALS, TAMELANDER J, TURNER JR, VISRAM S, VOGLER C, VOGT S, WOLSCHKE H, YANG JMC, YANG SY, YESSON C. Reefs and islands of the Chagos Archipelago, Indian Ocean: why it is the world's largest no-take marine protected area. Aquat Conserv 2012; 22:232-261. [PMID: 25505830 PMCID: PMC4260629 DOI: 10.1002/aqc.1248] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The Chagos Archipelago was designated a no-take marine protected area (MPA) in 2010; it covers 550 000 km2, with more than 60 000 km2 shallow limestone platform and reefs. This has doubled the global cover of such MPAs.It contains 25-50% of the Indian Ocean reef area remaining in excellent condition, as well as the world's largest contiguous undamaged reef area. It has suffered from warming episodes, but after the most severe mortality event of 1998, coral cover was restored after 10 years.Coral reef fishes are orders of magnitude more abundant than in other Indian Ocean locations, regardless of whether the latter are fished or protected.Coral diseases are extremely low, and no invasive marine species are known.Genetically, Chagos marine species are part of the Western Indian Ocean, and Chagos serves as a 'stepping-stone' in the ocean.The no-take MPA extends to the 200 nm boundary, and. includes 86 unfished seamounts and 243 deep knolls as well as encompassing important pelagic species.On the larger islands, native plants, coconut crabs, bird and turtle colonies were largely destroyed in plantation times, but several smaller islands are in relatively undamaged state.There are now 10 'important bird areas', coconut crab density is high and numbers of green and hawksbill turtles are recovering.Diego Garcia atoll contains a military facility; this atoll contains one Ramsar site and several 'strict nature reserves'. Pollutant monitoring shows it to be the least polluted inhabited atoll in the world. Today, strict environmental regulations are enforced.Shoreline erosion is significant in many places. Its economic cost in the inhabited part of Diego Garcia is very high, but all islands are vulnerable.Chagos is ideally situated for several monitoring programmes, and use is increasingly being made of the archipelago for this purpose.
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Affiliation(s)
| | - M. ATEWEBERHAN
- School of Life Sciences, University of Warwick, CV4 7AL, UK
| | - B. W. BOWEN
- Hawai’i Institute of Marine Biology, P.O. Box 1346, Kane’ohe, Hawai’i. 96744, USA
| | - P. CARR
- BF BIOT, Diego Garcia, BIOT, BFPO 485, UK
| | - C. A. CHEN
- Biodiversity Research Centre, Academia Sinica, 128 Academia Road, Nankang, Taipei, 115, Taiwan
| | - C. CLUBBE
- Royal Botanic Gardens Kew, Richmond, Surrey TW9 3AB, UK
| | - M. T. CRAIG
- Department of Marine Sciences, University of Puerto Rico, Mayaguez, P.O. Box 9000, Mayaguez, PR 00681
| | - R. EBINGHAUS
- Department for Environmental Chemistry, Helmholtz-Zentrum Geesthacht, Zentrum für Material- und Küstenforschung GmbH, Max-Planck-Straße 1 I 21502, Geesthacht I, Germany
| | - J. EBLE
- Hawai’i Institute of Marine Biology, P.O. Box 1346, Kane’ohe, Hawai’i. 96744, USA
| | - N. FITZSIMMONS
- Institute for Applied Ecology, University of Canberra, ACT 2601, Australia
| | - M. R. GAITHER
- Hawai’i Institute of Marine Biology, P.O. Box 1346, Kane’ohe, Hawai’i. 96744, USA
| | - C-H. GAN
- Biodiversity Research Centre, Academia Sinica, 128 Academia Road, Nankang, Taipei, 115, Taiwan
| | - M. GOLLOCK
- Zoological Society of London, Regents Park, London, NW1 4RY, UK
| | - N. GUZMAN
- Nestor Guzman: NAVFACFE PWD DG Environmental, PSC 466 Box 5, FPO AP, 96595-0005
| | - N. A. J. GRAHAM
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia
| | - A. HARRIS
- School of Life Sciences, University of Warwick, CV4 7AL, UK
| | - R. JONES
- Zoological Society of London, Regents Park, London, NW1 4RY, UK
| | - S. KESHAVMURTHY
- Biodiversity Research Centre, Academia Sinica, 128 Academia Road, Nankang, Taipei, 115, Taiwan
| | - H. KOLDEWEY
- Zoological Society of London, Regents Park, London, NW1 4RY, UK
| | - C. G. LUNDIN
- IUCN Marine Programme, Rue Mauverney 28, Gland, 1196, Switzerland
| | - J. A. MORTIMER
- Department of Biology, University of Florida, Gainesville, Florida, USA
| | - D. OBURA
- CORDIO East Africa, #9 Kibaki Flats, Kenyatta Beach, Bamburi Beach, P.O.BOX 10135, Mombasa 80101, Kenya
| | - M. PFEIFFER
- RWTH Aachen University, Templergraben 55, 52056 Aachen, Germany
| | - A. R. G. PRICE
- School of Life Sciences, University of Warwick, CV4 7AL, UK
| | - S. PURKIS
- National Coral Reef Institute, Nova Southeastern University, Oceanographic Center, 8000 North Ocean Drive, Dania Beach, FL 33004, USA
| | - P. RAINES
- Coral Cay Conservation, Elizabeth House, 39 York Road, London SE1 7NQ, UK
| | - J. W. READMAN
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, PL1 3DH, UK
| | - B. RIEGL
- National Coral Reef Institute, Nova Southeastern University, Oceanographic Center, 8000 North Ocean Drive, Dania Beach, FL 33004, USA
| | - A. ROGERS
- Department of Zoology, University of Oxford, The Tinbergen Building, South Parks Road, Oxford, OX1 3PS, UK
| | - M. SCHLEYER
- Oceanographic Research Institute, PO Box 10712, Marine Parade, Durban, 4056, South Africa
| | - M. R. D SEAWARD
- Division of Archaeological, Geographical and Environmental Sciences, University of Bradford, Bradford, West Yorkshire BD7 1DP, UK
| | | | - J. TAMELANDER
- UNEP Division of Environmental Policy Implementation, UN, Rajdamnern Nok Av., Bangkok, 10200, Thailand
| | - J. R. TURNER
- School of Ocean Sciences, Bangor University, Menai Bridge, Anglesey, LL59 5AB, UK
| | - S. VISRAM
- Biodiversity Research Centre, Academia Sinica, 128 Academia Road, Nankang, Taipei, 115, Taiwan
| | - C. VOGLER
- Department für Geo- und Umweltwissenschaften Paläontologie & Geobiologie, Ludwig- Maximilians-Universität, Richard-Wagner-Str.10, 80333, München, Germany
| | - S. VOGT
- Naval Facilities Engineering Command Far East, PSC 473, Box 1, FPO AP 96349, USA
| | - H. WOLSCHKE
- Department for Environmental Chemistry, Helmholtz-Zentrum Geesthacht, Zentrum für Material- und Küstenforschung GmbH, Max-Planck-Straße 1 I 21502, Geesthacht I, Germany
| | - J. M-C. YANG
- Biodiversity Research Centre, Academia Sinica, 128 Academia Road, Nankang, Taipei, 115, Taiwan
| | - S-Y. YANG
- Biodiversity Research Centre, Academia Sinica, 128 Academia Road, Nankang, Taipei, 115, Taiwan
| | - C. YESSON
- Zoological Society of London, Regents Park, London, NW1 4RY, UK
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