1
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Chavez DE, Hains T, Espinoza-Ulloa S, Wayne RK, Chaves JA. Whole-genome analysis reveals the diversification of Galapagos rail (Aves: Rallidae) and confirms the success of goat eradication programs. J Hered 2024; 115:444-457. [PMID: 38498380 DOI: 10.1093/jhered/esae017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 02/09/2024] [Accepted: 03/15/2024] [Indexed: 03/20/2024] Open
Abstract
Similar to other insular birds around the world, the Galapagos rail (Laterallus spilonota Gould, 1841) exhibits reduced flight capacity following its colonization of the archipelago ~1.2 mya. Despite their short evolutionary history, rails have colonized seven different islands spanning the entire width of the archipelago. Galapagos rails were once common on islands with sufficiently high altitudes to support shrubs in humid habitats. After humans introduced goats, this habitat was severely reduced due to overgrazing. Habitat loss devastated some rail populations, with less than 50 individuals surviving, rendering the genetic diversity of Galapagos rail a pressing conservation concern. Additionally, one enigma is the reappearance of rails on the island of Pinta after they were considered extirpated. Our approach was to investigate the evolutionary history and geographic distribution of Galapagos rails as well as examine the genome-wide effects of historical population bottlenecks using 39 whole genomes across different island populations. We recovered an early divergence of rail ancestors leading to the isolated populations on Pinta and a second clade comprising the rest of the islands, historically forming a single landmass. Subsequently, the separation of the landmass ~900 kya may have led to the isolation of the Isabela population with more panmictic populations found on Santa Cruz and Santiago islands. We found that rails genomes contain long runs of homozygosity (>2 Mb) that could be related to the introduction of goats. Finally, our findings show that the modern eradication of goats was critical to avoiding episodes of inbreeding in most populations.
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Affiliation(s)
- Daniel E Chavez
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, Los Angeles, CA 90095, United States
- Escuela de Biología, Pontificia Universidad Católica del Ecuador, Av. 12 de Octubre, Quito 170901, Ecuador
- Arizona Cancer Evolution Center, The Biodesign Institute, AZ School of Life Sciences, Arizona State University, Tempe, AZ, United States
| | - Taylor Hains
- Committee on Evolutionary Biology, University of Chicago, Chicago, IL 60637, United States
- Negaunee Integrative Research Center, The Field Museum, Chicago, IL 60605, United States
- Grainger Bioinformatics Center, The Field Museum, Chicago, IL 60605, United States
| | - Sebastian Espinoza-Ulloa
- Escuela de Biología, Pontificia Universidad Católica del Ecuador, Av. 12 de Octubre, Quito 170901, Ecuador
| | - Robert K Wayne
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, Los Angeles, CA 90095, United States
| | - Jaime A Chaves
- Department of Biology, San Francisco State University, San Francisco, CA 94132-1722, United States
- Colegio de Ciencias Biológicas y Ambientales, Universidad San Francisco de Quito, Quito, Ecuador
- Galapagos Science Center, Universidad San Francisco de Quito USFQ, Islas Galápagos, Ecuador
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2
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Deem SL, Rivera S, Nieto‐Claudin A, Emmel E, Cabrera F, Blake S. Temperature along an elevation gradient determines Galapagos tortoise sex ratios. Ecol Evol 2023; 13:e10008. [PMID: 37091568 PMCID: PMC10116026 DOI: 10.1002/ece3.10008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 03/27/2023] [Accepted: 03/31/2023] [Indexed: 04/25/2023] Open
Abstract
Climate change threatens endemic island ectothermic reptiles that display small population sizes and temperature-dependent sex determination (TSD). Studies of captive Galapagos tortoises demonstrate type A TSD with warmer incubation temperatures producing females. However, there are few published data from free-living Galapagos tortoises on incubation temperature regimes, and none on hatchling sex ratios in the wild or the potential impacts of climate change on future sex ratios. We sought to address these deficits by quantifying incubation temperatures of nests and sex ratios of juvenile tortoises along an elevation gradient on Santa Cruz Island. We focused on three geographically separated nesting zones with mean elevations of 14 m (lower), 57 m (middle), and 107 m (upper) above sea level. Nest temperatures in 54 nests distributed across the three nesting zones were measured every 4 h throughout the incubation period using iButton thermochrons. We used coelioscopy to conduct visual exams of gonads to determine the sex of 40 juvenile tortoises from the three nesting zones. During the middle trimester of incubation, the period during which sex is determined in turtles, mean nest temperatures were 25.75°C (SD = 1.08) in the upper zone, and 27.02°C (SD = 1.09), and 27.09°C (SD = 0.85) in the middle and lower zones, respectively. The proportion of juveniles that was male increased from 11.1% in the lower zone and 9.5% in the middle zone, to 80% in the upper zone. A ca. 50 m increase in elevation induced a decrease of >1.25°C in mean nest temperature during the second trimester of incubation. Over the same elevation change, the proportion of males in the juvenile tortoise population increased by ca. 70%. Temperatures on Galapagos are predicted to increase by 1-4°C over the next 50 years, which is likely to increase the frequency of female tortoises across the archipelago.
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Affiliation(s)
- Sharon L. Deem
- One Government DriveSaint Louis Zoo Institute for Conservation MedicineSt. LouisMissouriUSA
- Charles Darwin FoundationSanta CruzGalapagos IslandsEcuador
| | - Sam Rivera
- Department of Animal HealthZoo AtlantaAtlantaGeorgiaUSA
| | - Ainoa Nieto‐Claudin
- One Government DriveSaint Louis Zoo Institute for Conservation MedicineSt. LouisMissouriUSA
- Charles Darwin FoundationSanta CruzGalapagos IslandsEcuador
| | - Evan Emmel
- The Maritime Aquarium at NorwalkNorwalkConnecticutUSA
| | - Freddy Cabrera
- Charles Darwin FoundationSanta CruzGalapagos IslandsEcuador
| | - Stephen Blake
- Charles Darwin FoundationSanta CruzGalapagos IslandsEcuador
- Department of BiologySaint Louis UniversitySt. LouisMissouriUSA
- Max Planck Institute of Animal BehaviorRadolfzellGermany
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3
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Galápagos tortoise stable isotope ecology and the 1850s Floreana Island Chelonoidis niger niger extinction. Sci Rep 2022; 12:22187. [PMID: 36564467 PMCID: PMC9789057 DOI: 10.1038/s41598-022-26631-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
A consequence of over 400 years of human exploitation of Galápagos tortoises (Chelonoidis niger ssp.) is the extinction of several subspecies and the decimation of others. As humans captured, killed, and/or removed tortoises for food, oil, museums, and zoos, they also colonized the archipelago resulting in the introduction of invasive plants, animals, and manipulated landscapes for farming, ranching, and infrastructure. Given current conservation and revitalization efforts for tortoises and their habitats, here we investigate nineteenth and twentieth century Galápagos tortoise dietary ecology using museum and archaeological specimens coupled with analysis of carbon (δ13Ccollagen and δ13Capatite), nitrogen (δ15N), hydrogen (δD) and oxygen (δ18Oapatite) stable isotopes and radiocarbon dating. We identify that Galápagos tortoise diets vary between and within islands over time, and that long-term anthropogenic impacts influenced change in tortoise stable isotope ecology by using 57 individual tortoises from 10 different subspecies collected between 1833 and 1967-a 134-year period. On lower elevation islands, which are often hotter and drier, tortoises tend to consume more C4 vegetation (cacti and grasses). Our research suggests human exploitation of tortoises and anthropogenic impacts on vegetation contributed to the extinction of the Floreana Island tortoise (C. n. niger) in the 1850s.
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4
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Human-induced ecological cascades: Extinction, restoration, and rewilding in the Galápagos highlands. Proc Natl Acad Sci U S A 2022; 119:e2203752119. [PMID: 35666867 PMCID: PMC9214511 DOI: 10.1073/pnas.2203752119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The Galápagos Islands are an iconic evolutionary and ecological setting, recognized to be both species-poor and ecologically sensitive. Here, we show an indirect ecological cascade initiated by whalers harvesting tortoises near the coast in the 1790s, which had lasting impacts on the highland interior of San Cristóbal Island. Our data also reveal how the replacement of endemic herbivores with exotic herbivores, namely, cattle, impacted the local vegetation. We advocate for the restoration of preimpact shrub species and tortoises to promote habitat rewilding, restoration, and especially the socioeconomic value of these highland ecosystems in providing tourist experiences. Oceanic islands support unique biotas but often lack ecological redundancy, so that the removal of a species can have a large effect on the ecosystem. The larger islands of the Galápagos Archipelago once had one or two species of giant tortoise that were the dominant herbivore. Using paleoecological techniques, we investigate the ecological cascade on highland ecosystems that resulted from whalers removing many thousands of tortoises from the lowlands. We hypothesize that the seasonal migration of a now-extinct tortoise species to the highlands was curtailed by decreased intraspecific competition. We find the trajectory of plant community dynamics changed within a decade of the first whaling vessels visiting the islands. Novel communities established, with a previously uncommon shrub, Miconia, replacing other shrubs of the genera Alternanthera and Acalypha. It was, however, the introduction of cattle and horses that caused the local extirpation of plant species, with the most extreme impacts being evident after c. 1930. This modified ecology is considered the natural state of the islands and has shaped subsequent conservation policy and practice. Restoration of El Junco Crater should emphasize exclusion of livestock, rewilding with tortoises, and expanding the ongoing plantings of Miconia to also include Acalypha and Alternanthera.
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5
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Negoita L, Gibbs JP, Jaramillo Díaz P. Cost‐effectiveness of water‐saving technologies for restoration of tropical dry forest: a case study from the Galapagos Islands, Ecuador. Restor Ecol 2021. [DOI: 10.1111/rec.13576] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Luka Negoita
- Charles Darwin Research Station Charles Darwin Foundation Santa Cruz Galapagos Ecuador
| | - James P. Gibbs
- Department of Environmental Biology State University of New York College of Environmental Science and Forestry Syracuse NY 13244 U.S.A
| | - Patricia Jaramillo Díaz
- Charles Darwin Research Station Charles Darwin Foundation Santa Cruz Galapagos Ecuador
- Department of Botany and Plant Physiology University of Malaga Malaga Spain
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6
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Urquía D, Gutierrez B, Pozo G, Pozo MJ, Torres MDL. Origin and dispersion pathways of guava in the Galapagos Islands inferred through genetics and historical records. Ecol Evol 2021; 11:15111-15131. [PMID: 34765164 PMCID: PMC8571588 DOI: 10.1002/ece3.8193] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 07/07/2021] [Accepted: 09/16/2021] [Indexed: 11/23/2022] Open
Abstract
Guava (Psidium guajava) is an aggressive invasive plant in the Galapagos Islands. Determining its provenance and genetic diversity could explain its adaptability and spread, and how this relates to past human activities. With this purpose, we analyzed 11 SSR markers in guava individuals from Isabela, Santa Cruz, San Cristobal, and Floreana islands in the Galapagos, as well as from mainland Ecuador. The mainland guava population appeared genetically differentiated from the Galapagos populations, with higher genetic diversity levels found in the former. We consistently found that the Central Highlands region of mainland Ecuador is one of the most likely origins of the Galapagos populations. Moreover, the guavas from Isabela and Floreana show a potential genetic input from southern mainland Ecuador, while the population from San Cristobal would be linked to the coastal mainland regions. Interestingly, the proposed origins for the Galapagos guava coincide with the first human settlings of the archipelago. Through approximate Bayesian computation, we propose a model where San Cristobal was the first island to be colonized by guava from the mainland, and then, it would have spread to Floreana and finally to Santa Cruz; Isabela would have been seeded from Floreana. An independent trajectory could also have contributed to the invasion of Floreana and Isabela. The pathway shown in our model agrees with the human colonization history of the different islands in the Galapagos. Our model, in conjunction with the clustering patterns of the individuals (based on genetic distances), suggests that guava introduction history in the Galapagos archipelago was driven by either a single event or a series of introduction events in rapid succession. We thus show that genetic analyses supported by historical sources can be used to track the arrival and spread of invasive species in novel habitats and the potential role of human activities in such processes.
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Affiliation(s)
- Diego Urquía
- Laboratorio de Biotecnología VegetalUniversidad San Francisco de Quito (USFQ)QuitoEcuador
| | - Bernardo Gutierrez
- Laboratorio de Biotecnología VegetalUniversidad San Francisco de Quito (USFQ)QuitoEcuador
- Department of ZoologyUniversity of OxfordOxfordUK
| | - Gabriela Pozo
- Laboratorio de Biotecnología VegetalUniversidad San Francisco de Quito (USFQ)QuitoEcuador
| | - Maria Jose Pozo
- Laboratorio de Biotecnología VegetalUniversidad San Francisco de Quito (USFQ)QuitoEcuador
| | - Maria de Lourdes Torres
- Laboratorio de Biotecnología VegetalUniversidad San Francisco de Quito (USFQ)QuitoEcuador
- Galapagos Science CenterUniversidad San Francisco de Quito and University of North Carolina at Chapel HillGalapagosEcuador
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7
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Charney ND, Bastille‐Rousseau G, Yackulic CB, Blake S, Gibbs JP. A greener future for the Galapagos: forecasting ecosystem productivity by finding climate analogs in time. Ecosphere 2021. [DOI: 10.1002/ecs2.3753] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- Noah D. Charney
- Department of Wildlife, Fisheries, and Conservation Biology University of Maine Orono Maine USA
- WildCare Institute, Saint Louis Zoo,1 Government Drive Saint Louis Missouri USA
| | - Guillaume Bastille‐Rousseau
- Cooperative Wildlife Research Laboratory Southern Illinois University 1263 Lincoln Dr Carbondale United States 62901 USA
| | - Charles B. Yackulic
- U.S. Geological Survey Southwest Biological Science Center Flagstaff Arizona USA
| | - Stephen Blake
- Biology Department Saint Louis University Saint Louis Missouri USA
- Max Planck Institute for Animal Behaviour Radolfzell Germany
| | - James P. Gibbs
- Department of Environmental Biology College of Environmental Science and Forestry State University of New York Syracuse New York USA
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8
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Abstract
The Galapagos Islands are a global hotspot of environmental change. However, despite their potentially major repercussions, little is known about current and expected changes in regional terrestrial climate variables and sea surface temperatures (SST). Here, by analysing existing meteorological observations and secondary datasets, we find that the Islands have warmed by about 0.6 °C since the early 1980s, while at the same time becoming drier. In fact, the onset of the wet season is currently delayed 20 days. This drying trend may reverse, however, given that future climate projections for the region suggest mean annual precipitation may increase between 20 and 70%. This would also be accompanied by more extreme wet and hot conditions. Further, we find that regional SST has increased by 1.2 °C over the last two decades. These changes will, in turn, translate into deterioration of marine ecosystems and coral, proliferation of invasive species, and damages to human water, food, and infrastructure systems. Future projections, however, may be overestimated due to the poor capacity of climatic models to capture Eastern-Pacific ENSO dynamics. Our findings emphasize the need to design resilient climate adaptation policies that will remain robust in the face of a wide range of uncertain and changing climatic futures.
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9
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Nogué S, Santos AMC, Birks HJB, Björck S, Castilla-Beltrán A, Connor S, de Boer EJ, de Nascimento L, Felde VA, Fernández-Palacios JM, Froyd CA, Haberle SG, Hooghiemstra H, Ljung K, Norder SJ, Peñuelas J, Prebble M, Stevenson J, Whittaker RJ, Willis KJ, Wilmshurst JM, Steinbauer MJ. The human dimension of biodiversity changes on islands. Science 2021; 372:488-491. [PMID: 33926949 DOI: 10.1126/science.abd6706] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 03/31/2021] [Indexed: 01/23/2023]
Abstract
Islands are among the last regions on Earth settled and transformed by human activities, and they provide replicated model systems for analysis of how people affect ecological functions. By analyzing 27 representative fossil pollen sequences encompassing the past 5000 years from islands globally, we quantified the rates of vegetation compositional change before and after human arrival. After human arrival, rates of turnover accelerate by a median factor of 11, with faster rates on islands colonized in the past 1500 years than for those colonized earlier. This global anthropogenic acceleration in turnover suggests that islands are on trajectories of continuing change. Strategies for biodiversity conservation and ecosystem restoration must acknowledge the long duration of human impacts and the degree to which ecological changes today differ from prehuman dynamics.
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Affiliation(s)
- Sandra Nogué
- School of Geography and Environmental Science, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
| | - Ana M C Santos
- Centre for Ecology, Evolution and Environmental Changes (cE3c), Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal/Azores Biodiversity Group and Universidade dos Açores, 9700-042 Angra do Heroísmo, Azores, Portugal.,Global Change Ecology and Evolution Group (GloCEE), Department of Life Sciences, Universidad de Alcalá, 28805 Alcalá de Henares, Madrid, Spain.,Terrestrial Ecology Group (TEG-UAM), Departamento de Ecología, Universidad Autónoma de Madrid, 28049 Madrid, Spain.,Centro de Investigación en Biodiversidad y Cambio Global (CIBC-UAM), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - H John B Birks
- Department of Biological Sciences and Bjerknes Centre for Climate Research, University of Bergen, N-5020 Bergen, Norway.,Environmental Change Research Centre, University College London, London WC1E 6BT, UK
| | - Svante Björck
- Department of Geology, Lund University, SE-223 62 Lund, Sweden
| | - Alvaro Castilla-Beltrán
- School of Geography and Environmental Science, University of Southampton, Highfield, Southampton SO17 1BJ, UK
| | - Simon Connor
- School of Culture, History and Language, College of Asia and the Pacific, Australian National University, Australian Capital Territory 2601, Australia.,Australian Research Center (ARC) Centre of Excellence for Australian Biodiversity and Heritage, Australian National University, Australian Capital Territory 2601, Australia
| | - Erik J de Boer
- Departament d'Estratigrafia, Paleontologia i Geociències Marines, Facultat de Ciències de la Terra, Universitat de Barcelona, Martí i Franquès s/n, 08028 Barcelona, Catalonia, Spain
| | - Lea de Nascimento
- Island Ecology and Biogeography Group, Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias (IUETSPC), Universidad de La Laguna (ULL), 38200 La Laguna, Canary Islands, Spain.,Long-term Ecology Laboratory, Manaaki Whenua Landcare Research, 7640 Lincoln, New Zealand
| | - Vivian A Felde
- Department of Biological Sciences and Bjerknes Centre for Climate Research, University of Bergen, N-5020 Bergen, Norway
| | - José María Fernández-Palacios
- Island Ecology and Biogeography Group, Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias (IUETSPC), Universidad de La Laguna (ULL), 38200 La Laguna, Canary Islands, Spain
| | - Cynthia A Froyd
- Department of Biosciences, Swansea University, Singleton Park, Swansea SA2 8PP, UK
| | - Simon G Haberle
- School of Culture, History and Language, College of Asia and the Pacific, Australian National University, Australian Capital Territory 2601, Australia.,Australian Research Center (ARC) Centre of Excellence for Australian Biodiversity and Heritage, Australian National University, Australian Capital Territory 2601, Australia
| | - Henry Hooghiemstra
- Department of Ecosystem and Landscape Dynamics, Institute of Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, 1098XH Amsterdam, Netherlands
| | - Karl Ljung
- Department of Geology, Lund University, SE-223 62 Lund, Sweden
| | - Sietze J Norder
- Leiden University Centre for Linguistics. 2300 RA Leiden, Netherlands
| | - Josep Peñuelas
- CSIC, Global Ecology Unit CREAF-CSIC-UAB, Bellaterra, 08193 Barcelona, Catalonia, Spain.,CREAF, Cerdanyola del Vallès, 08193 Barcelona, Catalonia, Spain
| | - Matthew Prebble
- School of Culture, History and Language, College of Asia and the Pacific, Australian National University, Australian Capital Territory 2601, Australia.,School of Earth and Environment, College of Science, University of Canterbury, Christchurch 8140, New Zealand
| | - Janelle Stevenson
- School of Culture, History and Language, College of Asia and the Pacific, Australian National University, Australian Capital Territory 2601, Australia.,Australian Research Center (ARC) Centre of Excellence for Australian Biodiversity and Heritage, Australian National University, Australian Capital Territory 2601, Australia
| | - Robert J Whittaker
- School of Geography and the Environment, University of Oxford, Oxford OX1 3QY, UK.,Center for Macroecology, Evolution and Climate, GLOBE Institute, University of Copenhagen, 2100 Copenhagen 2100, Denmark
| | - Kathy J Willis
- Oxford Long-Term Ecology Laboratory, Department of Zoology, University of Oxford, Oxford OX1 3PS, UK
| | - Janet M Wilmshurst
- Long-term Ecology Laboratory, Manaaki Whenua Landcare Research, 7640 Lincoln, New Zealand.,School of Environment, University of Auckland, 1142 Auckland, New Zealand
| | - Manuel J Steinbauer
- Bayreuth Center of Ecology and Environmental Research (BayCEER) and Department of Sport Science, University of Bayreuth, 95447 Bayreuth, Germany. .,Department of Biological Sciences, University of Bergen, N-5020 Bergen, Norway
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10
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Valle CA, Ulloa C, Regalado C, Muñoz-Pérez JP, Garcia J, Hardesty BD, Skehel A, Deresienski D, Passingham RK, Lewbart GA. Baseline haematology, biochemistry, blood gas values and health status of the Galapagos swallow-tailed gull ( Creagrus furcatus). CONSERVATION PHYSIOLOGY 2020; 8:coaa064. [PMID: 34336215 PMCID: PMC7428447 DOI: 10.1093/conphys/coaa064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 06/01/2020] [Accepted: 07/05/2020] [Indexed: 06/13/2023]
Abstract
The swallow-tailed gull, Creagrus furcatus, is a seabird endemic to the Galápagos archipelago. In general health, blood chemistry and haematology, parameters have not been published for this species. Blood analyses were run on samples drawn from 58 clinically healthy swallow-tailed gulls captured at Islote Pitt on San Cristóbal Island in July 2016 (28) and South Plaza Island in June 2017 (30). A point of care blood analyzer (iSTAT) was used in the field to obtain results for HCO3 -, pH, pCO2, pO2, TCO2, anion gap, chloride, creatinine, glucose, haematocrit, haemoglobin, ionized calcium, potassium, sodium and urea nitrogen. A portable Lactate Plus™ analyzer was used to measure lactate. The baseline data reported is valuable for comparisons amongst different populations in the archipelago and to detect changes in health status of Galápagos swallow-tailed gulls.
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Affiliation(s)
- Carlos A Valle
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias Biológicas y Ambientales COCIBA, Campus Cumbayá Av. Diego de Robles S/N e Interoceánica, Quito, Ecuador
- Universidad San Francisco de Quito (USFQ) & UNC-Chapel Hill Galápagos Science Center (GSC) Av. Alsacio Northia, Isla San Cristobal, Galápagos, Ecuador
| | - Catalina Ulloa
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias Biológicas y Ambientales COCIBA, Campus Cumbayá Av. Diego de Robles S/N e Interoceánica, Quito, Ecuador
- Universidad San Francisco de Quito (USFQ) & UNC-Chapel Hill Galápagos Science Center (GSC) Av. Alsacio Northia, Isla San Cristobal, Galápagos, Ecuador
| | - Cristina Regalado
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias Biológicas y Ambientales COCIBA, Campus Cumbayá Av. Diego de Robles S/N e Interoceánica, Quito, Ecuador
| | - Juan-Pablo Muñoz-Pérez
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias Biológicas y Ambientales COCIBA, Campus Cumbayá Av. Diego de Robles S/N e Interoceánica, Quito, Ecuador
- Universidad San Francisco de Quito (USFQ) & UNC-Chapel Hill Galápagos Science Center (GSC) Av. Alsacio Northia, Isla San Cristobal, Galápagos, Ecuador
- University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs QLD 4556, Australia
| | - Juan Garcia
- Applied Marine Research, Galápagos National Park, Av. Charles Darwin y S/N
Isla Santa Cruz, Ecuador
| | - Britta Denise Hardesty
- Commonwealth Scientific and Industrial Research Organization, Avian Research, Tasmania, Australia
| | - Alice Skehel
- Universidad San Francisco de Quito (USFQ) & UNC-Chapel Hill Galápagos Science Center (GSC) Av. Alsacio Northia, Isla San Cristobal, Galápagos, Ecuador
| | - Diane Deresienski
- North Carolina State University College of Veterinary Medicine, Clinical Sciences, 1060 William Moore Drive, Raleigh, North Carolina, 27607, United States
| | - Ronald K Passingham
- North Carolina State University College of Veterinary Medicine, Clinical Sciences, 1060 William Moore Drive, Raleigh, North Carolina, 27607, United States
| | - Gregory A Lewbart
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias Biológicas y Ambientales COCIBA, Campus Cumbayá Av. Diego de Robles S/N e Interoceánica, Quito, Ecuador
- Universidad San Francisco de Quito (USFQ) & UNC-Chapel Hill Galápagos Science Center (GSC) Av. Alsacio Northia, Isla San Cristobal, Galápagos, Ecuador
- North Carolina State University College of Veterinary Medicine, Clinical Sciences, 1060 William Moore Drive, Raleigh, North Carolina, 27607, United States
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11
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Adolf C, Tovar C, Kühn N, Behling H, Berrío JC, Dominguez-Vázquez G, Figueroa-Rangel B, Gonzalez-Carranza Z, Islebe GA, Hooghiemstra H, Neff H, Olvera-Vargas M, Whitney B, Wooller MJ, Willis KJ. Identifying drivers of forest resilience in long-term records from the Neotropics. Biol Lett 2020; 16:20200005. [PMID: 32228400 DOI: 10.1098/rsbl.2020.0005] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Here, we use 30 long-term, high-resolution palaeoecological records from Mexico, Central and South America to address two hypotheses regarding possible drivers of resilience in tropical forests as measured in terms of recovery rates from previous disturbances. First, we hypothesize that faster recovery rates are associated with regions of higher biodiversity, as suggested by the insurance hypothesis. And second, that resilience is due to intrinsic abiotic factors that are location specific, thus regions presently displaying resilience in terms of persistence to current climatic disturbances should also show higher recovery rates in the past. To test these hypotheses, we applied a threshold approach to identify past disturbances to forests within each sequence. We then compared the recovery rates to these events with pollen richness before the event. We also compared recovery rates of each site with a measure of present resilience in the region as demonstrated by measuring global vegetation persistence to climatic perturbations using satellite imagery. Preliminary results indeed show a positive relationship between pre-disturbance taxonomic richness and faster recovery rates. However, there is less evidence to support the concept that resilience is intrinsic to a region; patterns of resilience apparent in ecosystems presently are not necessarily conservative through time.
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Affiliation(s)
- C Adolf
- Long-Term Ecology Laboratory, Department of Zoology, University of Oxford, Oxford, UK
| | - C Tovar
- Biodiversity Informatics and Spatial Analysis, Royal Botanic Gardens Kew, Richmond, UK
| | - N Kühn
- Biodiversity Informatics and Spatial Analysis, Royal Botanic Gardens Kew, Richmond, UK.,School of Geography and the Environment, University of Oxford, Oxford, UK
| | - H Behling
- University of Göttingen, Department of Palynology and Climate Dynamics, Albrecht-von-Haller Institute for Plant Sciences, University of Göttingen, Göttingen, Germany
| | - J C Berrío
- School of Geography, Geology and Environment, University of Leicester, Leicester, UK
| | - G Dominguez-Vázquez
- Universidad Michoacana de San Nicolás de Hidalgo, Facultad de Biología. Morelia, México
| | - B Figueroa-Rangel
- Departamento de Ecología y Recursos Naturales, Centro Universitario de la Costa Sur, Universidad de Guadalajara, Mexico
| | - Z Gonzalez-Carranza
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - G A Islebe
- Departamento de Conservación de la Biodiversidad, El Colegio de la Frontera Sur (ECOSUR), Chetumal, Mexico
| | - H Hooghiemstra
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - H Neff
- Department of Anthropology and IIIRMES, California State University, Long Beach, USA
| | - M Olvera-Vargas
- Departamento de Ecología y Recursos Naturales, Centro Universitario de la Costa Sur, Universidad de Guadalajara, Mexico
| | - B Whitney
- Department of Geography and Environmental Science, Northumbria University, Newcastle-upon-Tyne, UK
| | - M J Wooller
- Institute of Northern Engineering and College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, USA
| | - K J Willis
- Long-Term Ecology Laboratory, Department of Zoology, University of Oxford, Oxford, UK
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12
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Duchicela J, Bever JD, Schultz PA. Symbionts as Filters of Plant Colonization of Islands: Tests of Expected Patterns and Environmental Consequences in the Galapagos. PLANTS (BASEL, SWITZERLAND) 2020; 9:E74. [PMID: 31936005 PMCID: PMC7020428 DOI: 10.3390/plants9010074] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 12/20/2019] [Accepted: 12/23/2019] [Indexed: 11/16/2022]
Abstract
The establishments of new organisms that arrive naturally or with anthropogenic assistance depend primarily on local conditions, including biotic interactions. We hypothesized that plants that rely on fungal symbionts are less likely to successfully colonize remote environments such as oceanic islands, and this can shape subsequent island ecology. We analyzed the mycorrhizal status of Santa Cruz Island, Galapagos flora compared with the mainland Ecuador flora of origin. We experimentally determined plant responsiveness and plant-soil feedback of the island flora and assessed mycorrhizal density and soil aggregate stability of island sites. We found that a greater proportion of the native island flora species belongs to families that typically do not associate with mycorrhizal fungi than expected based upon the mainland flora of origin and the naturalized flora of the island. Native plants benefited significantly less from soil fungi and had weaker negative soil feedbacks than introduced species. This is consistent with the observation that field sites dominated by native plant species had lower arbuscular mycorrhizal (AM) fungal density and lower soil aggregate stability than invaded field sites at the island. We found support for a mycorrhizal filter to the initial colonization of the Galapagos.
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Affiliation(s)
- Jessica Duchicela
- Universidad de las Fuerzas Armadas-ESPE, Departamento de Ciencias de la Vida, Sangolquí 171103, Ecuador
- Indiana University, Biology Department, Bloomington, IN 47405, USA
| | - James D. Bever
- Department of Ecology and Evolution, and Kansas Biological Survey, Kansas University, Lawrence, KS 66047, USA;
| | - Peggy A. Schultz
- Environmental Studies Program, and Kansas Biological Survey, University of Kansas, Lawrence, KS 66047, USA;
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13
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Tapia PI, Negoita L, Gibbs JP, Jaramillo P. Effectiveness of water-saving technologies during early stages of restoration of endemic Opuntia cacti in the Galápagos Islands, Ecuador. PeerJ 2019; 7:e8156. [PMID: 31824769 PMCID: PMC6896940 DOI: 10.7717/peerj.8156] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 11/04/2019] [Indexed: 11/20/2022] Open
Abstract
Restoration of keystone species is a primary strategy used to combat biodiversity loss and recover ecological services. This is particularly true for oceanic islands, which despite their small land mass, host a large fraction of the planet’s imperiled species. The endemic Opuntia spp. cacti are one example and a major focus for restoration in the Galápagos archipelago, Ecuador. These cacti are keystone species that support much of the unique vertebrate animal community in arid zones, yet human activities have substantially reduced Opuntia populations. Extreme aridity poses an obstacle for quickly restoring Opuntia populations though water-saving technologies may provide a solution. The aim of this study was to evaluate current restoration efforts and the utility of two water-saving technologies as tools for the early stages of restoring Opuntia populations in the Galápagos archipelago. We planted 1,425 seedlings between 2013 and 2018, of which 66% had survived by the end of 2018. Compared with no-technology controls, seedlings planted with Groasis Waterboxx® water-saving technology (polypropylene trays with water reservoir and protective refuge for germinants) had a greater rate of survival in their first two-years of growth on one island (Plaza Sur) and greater growth rate on four islands whereas the “Cocoon” water-saving technology (similar technology but made of biodegradable fiber) did not affect growth and actually reduced seedling survival. Survival and growth rate were also influenced by vegetation zone, elevation, and precipitation in ways largely contingent on island. Overall, our findings suggest that water-saving technologies are not always universally applicable but can substantially increase the survival and growth rate of seedlings in certain conditions, providing in some circumstances a useful tool for improving restoration outcomes for rare plants of arid ecosystems.
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Affiliation(s)
- Patricia Isabela Tapia
- School of Natural and Environmental Sciences, Newcastle University, Newcastle Upon Tyne, Tyne and Wear, United Kingdom.,Charles Darwin Research Station, Charles Darwin Foundation, Santa Cruz, Galápagos, Ecuador
| | - Luka Negoita
- Charles Darwin Research Station, Charles Darwin Foundation, Santa Cruz, Galápagos, Ecuador
| | - James P Gibbs
- Department of Environmental and Forest Biology, State University of New York, Syracuse, NY, United States of America
| | - Patricia Jaramillo
- Charles Darwin Research Station, Charles Darwin Foundation, Santa Cruz, Galápagos, Ecuador.,Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
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14
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Urquía D, Gutierrez B, Pozo G, Pozo MJ, Espín A, Torres MDL. Psidium guajava in the Galapagos Islands: Population genetics and history of an invasive species. PLoS One 2019; 14:e0203737. [PMID: 30865637 PMCID: PMC6415804 DOI: 10.1371/journal.pone.0203737] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 02/07/2019] [Indexed: 11/30/2022] Open
Abstract
The threat of invasive plant species in island populations prompts the need to better understand their population genetics and dynamics. In the Galapagos islands, this is exemplified by the introduced guava (Psidium guajava), considered one of the greatest threats to the local biodiversity due to its effective spread in the archipelago and its ability to outcompete endemic species. To better understand its history and genetics, we analyzed individuals from three inhabited islands in the Galapagos archipelago with 11 SSR markers. Our results reveal similar genetic diversity between islands, and the populations appear to be distinct: the islands of San Cristobal and Isabela are genetically different while the population of Santa Cruz is a mixture from both. Additional evidence for genetic bottlenecks and the inference of introduction events suggests an original introduction of the species in San Cristobal, from where it was later introduced to Isabela, and finally into Santa Cruz. Alternatively, a second introduction in Isabela might have occurred. These results are contrasted with the historical record, providing a first overview of the history of P. guajava in the Galapagos islands and its current population dynamics.
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Affiliation(s)
- Diego Urquía
- Universidad San Francisco de Quito (USFQ), Colegio de Ciencias Biológicas y Ambientales, Laboratorio de Biotecnología Vegetal, Campus Cumbayá, Quito, Ecuador
| | - Bernardo Gutierrez
- Universidad San Francisco de Quito (USFQ), Colegio de Ciencias Biológicas y Ambientales, Laboratorio de Biotecnología Vegetal, Campus Cumbayá, Quito, Ecuador
- Department of Zoology, University of Oxford, South Parks Road, Oxford, United Kingdom
| | - Gabriela Pozo
- Universidad San Francisco de Quito (USFQ), Colegio de Ciencias Biológicas y Ambientales, Laboratorio de Biotecnología Vegetal, Campus Cumbayá, Quito, Ecuador
| | - María José Pozo
- Universidad San Francisco de Quito (USFQ), Colegio de Ciencias Biológicas y Ambientales, Laboratorio de Biotecnología Vegetal, Campus Cumbayá, Quito, Ecuador
| | - Analía Espín
- Universidad San Francisco de Quito (USFQ), Colegio de Ciencias Biológicas y Ambientales, Laboratorio de Biotecnología Vegetal, Campus Cumbayá, Quito, Ecuador
| | - María de Lourdes Torres
- Universidad San Francisco de Quito (USFQ), Colegio de Ciencias Biológicas y Ambientales, Laboratorio de Biotecnología Vegetal, Campus Cumbayá, Quito, Ecuador
- Galapagos Science Center, Universidad San Francisco de Quito and University of North Carolina at Chapel Hill, San Cristobal, Galapagos, Ecuador
- * E-mail:
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15
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Lorant A, Pedersen S, Holst I, Hufford MB, Winter K, Piperno D, Ross-Ibarra J. The potential role of genetic assimilation during maize domestication. PLoS One 2017; 12:e0184202. [PMID: 28886108 PMCID: PMC5590903 DOI: 10.1371/journal.pone.0184202] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 08/18/2017] [Indexed: 11/25/2022] Open
Abstract
Domestication research has largely focused on identification of morphological and genetic differences between extant populations of crops and their wild relatives. Little attention has been paid to the potential effects of environment despite substantial known changes in climate from the time of domestication to modern day. In recent research, the exposure of teosinte (i.e., wild maize) to environments similar to the time of domestication, resulted in a plastic induction of domesticated phenotypes in teosinte. These results suggest that early agriculturalists may have selected for genetic mechanisms that cemented domestication phenotypes initially induced by a plastic response of teosinte to environment, a process known as genetic assimilation. To better understand this phenomenon and the potential role of environment in maize domestication, we examined differential gene expression in maize (Zea mays ssp. mays) and teosinte (Zea mays ssp. parviglumis) between past and present conditions. We identified a gene set of over 2000 loci showing a change in expression across environmental conditions in teosinte and invariance in maize. In fact, overall we observed both greater plasticity in gene expression and more substantial changes in co-expressionnal networks in teosinte across environments when compared to maize. While these results suggest genetic assimilation played at least some role in domestication, genes showing expression patterns consistent with assimilation are not significantly enriched for previously identified domestication candidates, indicating assimilation did not have a genome-wide effect.
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Affiliation(s)
- Anne Lorant
- Dept. of Plant Sciences, University of California Davis, Davis, CA, United States of America
| | - Sarah Pedersen
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, United States of America
| | - Irene Holst
- Smithsonian Tropical Research Institute, Panama, Republic of Panama
| | - Matthew B. Hufford
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, United States of America
| | - Klaus Winter
- Smithsonian Tropical Research Institute, Panama, Republic of Panama
| | - Dolores Piperno
- Smithsonian Tropical Research Institute, Panama, Republic of Panama
- Department of Anthropology, Smithsonian National Museum of Natural History, Washington, DC, United States of America
| | - Jeffrey Ross-Ibarra
- Dept. of Plant Sciences, University of California Davis, Davis, CA, United States of America
- Genome Center and Center for Population Biology, University of California Davis, Davis, CA, United States of America
- * E-mail:
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16
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Yackulic CB, Blake S, Bastille-Rousseau G. Benefits of the destinations, not costs of the journeys, shape partial migration patterns. J Anim Ecol 2017; 86:972-982. [PMID: 28390059 DOI: 10.1111/1365-2656.12679] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 03/26/2017] [Indexed: 11/29/2022]
Abstract
The reasons that lead some animals to seasonally migrate, and others to remain in the same area year-round, are poorly understood. Associations between traits, such as body size, and migration provide clues. For example, larger species and individuals are more likely to migrate. One explanation for this size bias in migration is that larger animals are capable of moving faster (movement hypothesis). However, body size is linked to many other biological processes. For instance, the energetic balances of larger animals are generally more sensitive to variation in food density because of body size effects on foraging and metabolism and this sensitivity could drive migratory decisions (forage hypothesis). Identifying the primary selective forces that drive migration ultimately requires quantifying fitness impacts over the full annual migratory cycle. Here, we develop a full annual migratory cycle model from metabolic and foraging theory to compare the importance of the forage and movement hypotheses. We parameterize the model for Galapagos tortoises, which were recently discovered to be size-dependent altitudinal migrants. The model predicts phenomena not included in model development including maximum body sizes, the body size at which individuals begin to migrate, and the seasonal timing of migration and these predictions generally agree with available data. Scenarios strongly support the forage hypothesis over the movement hypothesis. Furthermore, male Galapagos tortoises on Santa Cruz Island would be unable to grow to their enormous sizes without access to both highlands and lowlands. Whereas recent research has focused on links between traits and the migratory phases of the migratory cycle, we find that effects of body size on the non-migratory phases are far more important determinants of the propensity to migrate. Larger animals are more sensitive to changing forage conditions than smaller animals with implications for maintenance of migration and body size in the face of environmental change.
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Affiliation(s)
- Charles B Yackulic
- U.S. Geological Survey, Southwest Biological Science Center, 2255 N. Gemini Dr., Flagstaff, AZ, 86001, USA
| | - Stephen Blake
- Max Planck Institute for Ornithology, Radolfzell, Germany.,Whitney-Harris World Ecology Center, University of Missouri-St. Louis, St. Louis, MO, 63121, USA.,WildCare Institute, Saint Louis Zoo, St. Louis, MO, 63101, USA.,State University of New York, College of Environmental Science and Forestry, 1 Forestry Dr., Syracuse, NY, 13210, USA
| | - Guillaume Bastille-Rousseau
- State University of New York, College of Environmental Science and Forestry, 1 Forestry Dr., Syracuse, NY, 13210, USA.,Roosevelt Wild Life Station, State University of New York, College of Environmental Science and Forestry, Syracuse, NY, 13210, USA
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17
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Bastille-Rousseau G, Gibbs JP, Yackulic CB, Frair JL, Cabrera F, Rousseau LP, Wikelski M, Kümmeth F, Blake S. Animal movement in the absence of predation: environmental drivers of movement strategies in a partial migration system. OIKOS 2017. [DOI: 10.1111/oik.03928] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Guillaume Bastille-Rousseau
- Dept of Environmental and Forest Biology; State Univ. of New York, College of Environmental Science and Forestry; Syracuse, NY 13210 USA
| | - James P. Gibbs
- Dept of Environmental and Forest Biology; State Univ. of New York, College of Environmental Science and Forestry; Syracuse, NY 13210 USA
| | - Charles B. Yackulic
- U.S. Geological Survey, Southwest Biological Science Center, Grand Canyon Monitoring and Research Center; Flagstaff AZ USA
| | - Jacqueline L. Frair
- Dept of Environmental and Forest Biology; State Univ. of New York, College of Environmental Science and Forestry; Syracuse, NY 13210 USA
- Roosevelt Wild Life Station, State Univ. of New York, College of Environmental Science and Forestry; Syracuse NY USA
| | - Fredy Cabrera
- Charles Darwin Foundation, Puerto Ayora; Gal pagos Ecuador
| | | | | | | | - Stephen Blake
- Max Planck Inst. for Ornithology; Radolfzell Germany
- Wildcare Inst.; Saint Louis Zoo Saint Louis MO USA
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18
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Linking historical ecology and invasion biology: some lessons from European rabbit introductions into the new world before the nineteenth century. Biol Invasions 2015. [DOI: 10.1007/s10530-015-0905-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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19
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Blake S, Guézou A, Deem SL, Yackulic CB, Cabrera F. The Dominance of Introduced Plant Species in the Diets of Migratory Galapagos Tortoises Increases with Elevation on a Human-Occupied Island. Biotropica 2015. [DOI: 10.1111/btp.12195] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Stephen Blake
- Max Planck Institute for Ornithology; Vogelwarte Radolfzell; Schlossallee 2 Radolfzell D-78315 Germany
- Whitney R. Harris; World Ecology Center; University of Missouri-St. Louis; B216 Benton Hall One University Boulevard St. Louis MO 63121-4400 U.S.A
- WildCare Institute; Saint Louis Zoo; 1 Government Drive St. Louis MO 63110 U.S.A
- Department of Biology; Washington University; Campus Box 1137 1 Brookings Drive St. Louis MO 63130 U.S.A
- 247 Illick Hall; State University of New York College of Environmental Science and Forestry; 1 Forestry Drive Syracuse NY 13210 U.S.A
| | - Anne Guézou
- Charles Darwin Foundation; Isla Santa Cruz Puerto Ayora Casilla Quito Galápagos 17-01-3891 Ecuador
| | - Sharon L. Deem
- Whitney R. Harris; World Ecology Center; University of Missouri-St. Louis; B216 Benton Hall One University Boulevard St. Louis MO 63121-4400 U.S.A
- Institute for Conservation Medicine; Saint Louis Zoo; 1 Government Drive St. Louis MO 63110 U.S.A
| | - Charles B. Yackulic
- U.S. Geological Survey; Southwest Biological Science Center; Grand Canyon Monitoring and Research Center; 2255 North Gemini Drive (Mail Stop 9394) Flagstaff AZ 86001 U.S.A
| | - Fredy Cabrera
- Charles Darwin Foundation; Isla Santa Cruz Puerto Ayora Casilla Quito Galápagos 17-01-3891 Ecuador
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20
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21
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Bush MB, Restrepo A, Collins AF. Galápagos History, Restoration, and a Shifted Baseline. Restor Ecol 2014. [DOI: 10.1111/rec.12080] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Mark B. Bush
- Department of Biological Sciences; Florida Institute of Technology; 150 West University Boulevard Melbourne FL 32901 U.S.A
| | - Alejandra Restrepo
- Department of Biological Sciences; Florida Institute of Technology; 150 West University Boulevard Melbourne FL 32901 U.S.A
- Plant Biology Department of the School of Integrative Biology; University of Illinois; Urbana IL 61801 U.S.A
| | - Aaron F. Collins
- Department of Biological Sciences; Florida Institute of Technology; 150 West University Boulevard Melbourne FL 32901 U.S.A
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22
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Loire E, Chiari Y, Bernard A, Cahais V, Romiguier J, Nabholz B, Lourenço JM, Galtier N. Population genomics of the endangered giant Galápagos tortoise. Genome Biol 2013; 14:R136. [PMID: 24342523 PMCID: PMC4053747 DOI: 10.1186/gb-2013-14-12-r136] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 12/16/2013] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND The giant Galápagos tortoise, Chelonoidis nigra, is a large-sized terrestrial chelonian of high patrimonial interest. The species recently colonized a small continental archipelago, the Galápagos Islands, where it has been facing novel environmental conditions and limited resource availability. To explore the genomic consequences of this ecological shift, we analyze the transcriptomic variability of five individuals of C. nigra, and compare it to similar data obtained from several continental species of turtles. RESULTS Having clarified the timing of divergence in the Chelonoidis genus, we report in C. nigra a very low level of genetic polymorphism, signatures of a weakened efficacy of purifying selection, and an elevated mutation load in coding and regulatory sequences. These results are consistent with the hypothesis of an extremely low long-term effective population size in this insular species. Functional evolutionary analyses reveal a reduced diversity of immunity genes in C. nigra, in line with the hypothesis of attenuated pathogen diversity in islands, and an increased selective pressure on genes involved in response to stress, potentially related to the climatic instability of its environment and its elongated lifespan. Finally, we detect no population structure or homozygosity excess in our five-individual sample. CONCLUSIONS These results enlighten the molecular evolution of an endangered taxon in a stressful environment and point to island endemic species as a promising model for the study of the deleterious effects on genome evolution of a reduced long-term population size.
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Affiliation(s)
- Etienne Loire
- Université Montpellier 2, CNRS UMR 5554, Institut des Sciences de l’Evolution de Montpellier, Place E. Bataillon, 34095 Montpellier, France
| | - Ylenia Chiari
- Université Montpellier 2, CNRS UMR 5554, Institut des Sciences de l’Evolution de Montpellier, Place E. Bataillon, 34095 Montpellier, France
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Campus Agrário de Vairão, 4485-661 Vairão, Portugal
| | - Aurélien Bernard
- Université Montpellier 2, CNRS UMR 5554, Institut des Sciences de l’Evolution de Montpellier, Place E. Bataillon, 34095 Montpellier, France
| | - Vincent Cahais
- Université Montpellier 2, CNRS UMR 5554, Institut des Sciences de l’Evolution de Montpellier, Place E. Bataillon, 34095 Montpellier, France
| | - Jonathan Romiguier
- Université Montpellier 2, CNRS UMR 5554, Institut des Sciences de l’Evolution de Montpellier, Place E. Bataillon, 34095 Montpellier, France
| | - Benoît Nabholz
- Université Montpellier 2, CNRS UMR 5554, Institut des Sciences de l’Evolution de Montpellier, Place E. Bataillon, 34095 Montpellier, France
| | - Joao Miguel Lourenço
- Université Montpellier 2, CNRS UMR 5554, Institut des Sciences de l’Evolution de Montpellier, Place E. Bataillon, 34095 Montpellier, France
| | - Nicolas Galtier
- Université Montpellier 2, CNRS UMR 5554, Institut des Sciences de l’Evolution de Montpellier, Place E. Bataillon, 34095 Montpellier, France
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23
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Collins AF, Bush MB, Sachs JP. Microrefugia and species persistence in the Galápagos highlands: a 26,000-year paleoecological perspective. Front Genet 2013; 4:269. [PMID: 24348520 PMCID: PMC3848256 DOI: 10.3389/fgene.2013.00269] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 11/18/2013] [Indexed: 11/13/2022] Open
Abstract
The Galápagos Islands are known to have experienced significant drought during the Quaternary. The loss of mesophytic upland habitats has been suggested to underlie the relatively lower endemism of upland compared with lowland plant assemblages. A fossil pollen record spanning the last 26,000 years from an upland bog on Santa Cruz Island, revealed the persistent presence of highland pollen and spore types during the last glacial maximum and a millennial-scale series of droughts in the mid Holocene. The absence of lowland taxa and presence of mesic taxa led to the conclusion that the highland flora of the Galápagos persisted during both these periods. The resiliency of the highland flora of the Galápagos to long-term drought contradicts an earlier hypothesis that an extinction of highland taxa occurred during the last glacial maximum and that rapid Holocene speciation created the modern plant assemblage within the last 10,000 years. Based on the palynological data, we suggest that, even during the height of glacial and Holocene droughts, cool sea-surface temperatures and strong trade-wind activity would have promoted persistent ground level cloudiness that provided the necessary moisture inputs to maintain microrefugia for mesophytic plants. Although moist conditions were maintained, the lack of precipitation caused the loss of open water habitat during such events, and accounts for the known extinctions of species such as Azolla sp., and Elatine sp., while other moisture dependent taxa, i.e., Cyathea weatherbyana, persisted.
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Affiliation(s)
- Aaron F Collins
- Department of Biological Sciences, Florida Institute of Technology Melbourne, FL, USA
| | - Mark B Bush
- Department of Biological Sciences, Florida Institute of Technology Melbourne, FL, USA
| | - Julian P Sachs
- School of Oceanography, University of Washington Seattle, WA, USA
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24
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Heleno RH, Olesen JM, Nogales M, Vargas P, Traveset A. Seed dispersal networks in the Galápagos and the consequences of alien plant invasions. Proc Biol Sci 2013; 280:20122112. [PMID: 23173203 DOI: 10.1098/rspb.2012.2112] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Alien plants are a growing threat to the Galápagos unique biota. We evaluated the impact of alien plants on eight seed dispersal networks from two islands of the archipelago. Nearly 10 000 intact seeds from 58 species were recovered from the droppings of 18 bird and reptile dispersers. The most dispersed invaders were Lantana camara, Rubus niveus and Psidium guajava, the latter two likely benefiting from an asynchronous fruit production with most native plants, which facilitate their consumption and spread. Lava lizards dispersed the seeds of 27 species, being the most important dispersers, followed by small ground finch, two mockingbirds, the giant tortoise and two insectivorous birds. Most animals dispersed alien seeds, but these formed a relatively small proportion of the interactions. Nevertheless, the integration of aliens was higher in the island that has been invaded for longest, suggesting a time-lag between alien plant introductions and their impacts on seed dispersal networks. Alien plants become more specialized with advancing invasion, favouring more simplified plant and disperser communities. However, only habitat type significantly affected the overall network structure. Alien plants were dispersed via two pathways: dry-fruited plants were preferentially dispersed by finches, while fleshy fruited species were mostly dispersed by other birds and reptiles.
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Affiliation(s)
- Ruben H Heleno
- Centre for Functional Ecology, Department of Life Sciences, University of Coimbra, Coimbra, Portugal.
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