45 datasets found
  1. Thirteen Colonies: southern colonies population by ethnicity and state...

    • statista.com
    Updated Jan 1, 1999
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    Statista (1999). Thirteen Colonies: southern colonies population by ethnicity and state 1620-1760 [Dataset]. https://www.statista.com/statistics/1415538/thirteen-colonies-southern-colonies-pop-ethnicity-state/
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    Dataset updated
    Jan 1, 1999
    Dataset authored and provided by
    Statistahttp://statista.com/
    Area covered
    United States
    Description

    The Colony of Virginia, the location of the Jamestown Settlement (the first permanent English settlement in the Americas), was the most populous southern colony or state in the region until it was partitioned into Virginia and West Virginia during the American Civil War. Virginia was also the most populous of the Thirteen Colonies throughout most of the Colonial Era. In terms of ethnicity, the southern colonies had the largest relative Black populations, with South Carolina even becoming majority-Black in the 1710s.

  2. Thirteen Colonies: population by colony 1620-1760

    • statista.com
    Updated Jan 1, 1999
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    Statista (1999). Thirteen Colonies: population by colony 1620-1760 [Dataset]. https://www.statista.com/statistics/1415662/thirteen-colonies-pop-per-colony/
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    Dataset updated
    Jan 1, 1999
    Dataset authored and provided by
    Statistahttp://statista.com/
    Area covered
    United States
    Description

    For most of the colonial period, Virginia was the most populous of the Thirteen Colonies, apart from when it was overtaken by Massachusetts between 1710 and 1740. The Plymouth colony was one of the first permanent settlements in what would become the United States, but is not included as one of the Thirteen Colonies as it was incorporated into Massachusetts in 1691.

  3. Colony South, Gainesville, GA, US Demographics 2025

    • point2homes.com
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    Updated 2025
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    Point2Homes (2025). Colony South, Gainesville, GA, US Demographics 2025 [Dataset]. https://www.point2homes.com/US/Neighborhood/GA/Gainesville/Colony-South-Demographics.html
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    htmlAvailable download formats
    Dataset updated
    2025
    Dataset authored and provided by
    Point2Homeshttps://plus.google.com/116333963642442482447/posts
    Time period covered
    2025
    Area covered
    Gainesville, Colony South, Georgia, United States
    Variables measured
    Asian, Other, White, 2 units, Over 65, Median age, Blue collar, Mobile home, 3 or 4 units, 5 to 9 units, and 69 more
    Description

    Comprehensive demographic dataset for Colony South, Gainesville, GA, US including population statistics, household income, housing units, education levels, employment data, and transportation with year-over-year changes.

  4. Data from: Metapopulation dynamics and foraging plasticity in a highly...

    • zenodo.org
    zip
    Updated Jun 2, 2022
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    Nicolas Lois; Nicolas Lois; Leonardo Campagna; Ulises Balza; Michael Polito; Klemens Pütz; Juliana Vianna; Annick Morgenthaler; Esteban Frere; Ricardo Saenz-Samaniego; Andrea Raya Rey; Bettina Mahler; Leonardo Campagna; Ulises Balza; Michael Polito; Klemens Pütz; Juliana Vianna; Annick Morgenthaler; Esteban Frere; Ricardo Saenz-Samaniego; Andrea Raya Rey; Bettina Mahler (2022). Metapopulation dynamics and foraging plasticity in a highly vagile seabird, the southern rockhopper penguin [Dataset]. http://doi.org/10.5061/dryad.vmcvdncpx
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    zipAvailable download formats
    Dataset updated
    Jun 2, 2022
    Dataset provided by
    Zenodohttp://zenodo.org/
    Authors
    Nicolas Lois; Nicolas Lois; Leonardo Campagna; Ulises Balza; Michael Polito; Klemens Pütz; Juliana Vianna; Annick Morgenthaler; Esteban Frere; Ricardo Saenz-Samaniego; Andrea Raya Rey; Bettina Mahler; Leonardo Campagna; Ulises Balza; Michael Polito; Klemens Pütz; Juliana Vianna; Annick Morgenthaler; Esteban Frere; Ricardo Saenz-Samaniego; Andrea Raya Rey; Bettina Mahler
    License

    CC0 1.0 Universal Public Domain Dedicationhttps://creativecommons.org/publicdomain/zero/1.0/
    License information was derived automatically

    Description

    Population connectivity is driven by individual dispersal potential and modulated by natal philopatry. In seabirds, high vagility facilitates dispersal yet philopatry is also common, with foraging area overlap often correlated with population connectivity. We assess the interplay between these processes by studying past and current connectivity and foraging niche overlap among southern rockhopper penguin colonies of the coast of southern South America using genomic and stable isotope analyses. We found two distinct genetic clusters and detected low admixture between northern and southern colonies. Stable isotope analysis indicated niche variability between colonies, with Malvinas/Falklands colonies encompassing the species entire isotopic foraging niche, while the remaining colonies had smaller, nonoverlapping niches. A recently founded colony in continental Patagonia differed in isotopic niche width and position with Malvinas/Falklands colonies, its genetically identified founder population, suggesting the exploitation of novel foraging areas and/or prey items. Additionally, dispersing individuals found dead across the Patagonian shore in an unusual mortality event were also assigned to the northern cluster, suggesting northern individuals reach southern localities, but do not breed in these colonies. Facilitated by variability in foraging strategies, and especially during unfavorable conditions, the number of dispersing individuals may increase and enhance the probability of founding new colonies. Metapopulation demographic dynamics in seabirds should account for interannual variability in dispersal behavior and pay special attention to extreme climatic events, classically related to negative effects on population trends.

  5. n

    Data from: Natural coral recovery despite negative population growth

    • data.niaid.nih.gov
    zip
    Updated May 24, 2024
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    Aziz Mulla; Vianney Denis; Che-Hung Lin; Chia-Ling Fong; Jia-Ho Shiu; Yoko Nozawa (2024). Natural coral recovery despite negative population growth [Dataset]. http://doi.org/10.5061/dryad.msbcc2g5n
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    zipAvailable download formats
    Dataset updated
    May 24, 2024
    Dataset provided by
    National Taiwan University
    National Pingtung University of Science and Technology
    Academia Sinica
    University of the Ryukyus
    National Chiayi University
    Authors
    Aziz Mulla; Vianney Denis; Che-Hung Lin; Chia-Ling Fong; Jia-Ho Shiu; Yoko Nozawa
    License

    https://spdx.org/licenses/CC0-1.0.htmlhttps://spdx.org/licenses/CC0-1.0.html

    Description

    Demographic processes that ensure the recovery and resilience of marine populations are critical as climate change sends an increasing proportion on a trajectory of decline. Yet for some populations, recovery potential remains high. We conducted annual monitoring over 9-years (2012–2020) to assess the recovery of coral populations belonging to genus Pocillopora. These populations experienced a catastrophic collapse following a severe typhoon in 2009. From the start of the monitoring period, high initial recruitment led to the establishment of a juvenile population that rapidly transitioned to sexually mature adults, which dominated the population within six years after the disturbance. As a result, coral cover increased from 1.1% to 20.2% during this time. To identify key demographic drivers of recovery and population growth rates (λ), we applied kernel resampled Integral Projection Models (IPMs), constructing eight successive models to examine annual change. IPMs were able to capture reproductive traits as key demographic drivers over the initial 3 years, whilst individual growth was a continuous key demographic driver throughout the entire monitoring period. IPMs further detected a pulse of reproductive output subsequent to two further Category 5 typhoon events during the monitoring period, exemplifying key mechanisms of resilience for coral populations impacted by disturbance. Despite rapid recovery, (i.e., increased coral cover, individual colony growth, low mortality), IPMs estimated predominantly negative values of λ, indicating a declining population. Indeed, whilst λ translates to a change in the number of individuals, the recovery of coral populations can also be driven by an increase in the size of coral surviving colonies. Our results illustrate that accumulating long-term data of historical dynamics and applying IPMs to extract demographic drivers are crucial for future predictions that are based on comprehensive and robust understandings of ecological change. Methods Data collection Orchid Island (22°03′N, 121°32′E) is a 45 km2 volcanic, tropical island 64 km off the coast of Taiwan, encircled by a narrow fringing reef (5–10 m depth), leading to a dramatic drop-off. Such reef topography is sensitive to typhoons that are both frequent and intense in the region (Ribas-Deulofeu et al., 2021). In 2009, the island was severely affected by Typhoon Morakot (Hall et al., 2013), the deadliest typhoon to hit Taiwan in recorded history, which caused a ~66% decline in mean live coral cover (~60% to ~20%) along reefs in southern Taiwan (Kuo et al., 2011). Three years after this major disturbance in 2012, three parallel 20 m transects were established at ~8 m depth spaced ~2.5 m apart at a site to the southwest of the island (named Green Grassland; 22°00'N 121°34'E). Usually, this reef site is relatively sheltered from both the waves generated by the winter north-easterly monsoon and summer south-westerly winds. However, on this occasion was proven susceptible to the typhoon in 2009, impacted by a west to south-westerly swell. To the side of each transect, 50 cm × 50 cm permanent quadrats (n = 11) were haphazardly positioned to assess demographic changes over time (Appendix S1: Figure S1 and Figure S2). A total of 33 quadrats were made permanent by placing markers (iron pegs) at each corner with tags attached indicating the designated identification number, making the quadrat easier to detect for future monitoring. With this method, only four quadrats were lost in subsequent surveys, whereas the position of the other quadrats (n = 29) remained. However, the precise location may slightly vary due to the ever-changing dynamics of the reef. For this reason, when quadrats were placed at each marked position, a wide-scale community picture was taken ca. 2 m above the substrate, in order to correct any error in positioning during the analysis, if necessary (Appendix S1: Figure S1a). The quadrat was then photographed at a higher-resolution ca. 1 m above the substrate in order to capture the overall benthic composition (Appendix S1: Figure S1b). The quadrat was then divided into four sections, which were individually captured in order to attain high-resolution images of individual colonies (Appendix S1: Figure S1c). In each of these sections, smaller sized individuals (ca. < 5 cm in length) were photographed with close-up images and scale. This protocol was repeated annually between 2012 and 2020. From photographs of the 29 permanent quadrats, every colony (n = 336) observed was first measured for its two-dimensional (2D) colony size (projected area) using Image J software (Schneider, Rasband and Eliceiri, 2012). The 2D colony size was used for the analysis of annual change in coral cover. Coral cover (%) was determined by measuring the sum of 2D projected areas of coral colonies relative to the area of all quadrats combined. All quadrats were originally occupied by Pocillopora, but from 2016 to the end of the monitoring period, 1 quadrat was empty of Pocillopora colonies with the cover calculation still taking this area into consideration. In the rare case of a slight overlap of colonies (n = 4), the 2D projected area could be easily deduced for the unseen part of colonies. Measurement of demographic vital rates In this study, we focused on locally dominant genus Pocillopora spp. The relative contribution of species to the Pocillopora complex was genetically examined by randomly sampling colonies at the site and barcoding mtORF region after extraction of genomic DNA (Johnston, Forsman and Toonen, 2018). Out of 31 sampled Pocillopora colonies, 17 were P. verrucosa and 14 were P. meandrina (Appendix S1: Table S1 and S2). Besides the two dominant Pocillopora species, there were at least two other Pocillopora species present; Pocillopora eydouxi and Pocillopora sp. These species are broadcast-spawners, with the exception of Pocillopora sp., which is a brooder (Mulla et al. 2021). Due to the difficulty in identifying species morphologically in the field, especially at the early life stages, we treated species as a Pocillopora complex (Pocillopora populations). As corals are 3D structures, colony size (surface area) was used for Pocillopora colonies in the IPMs, which allowed us to build higher-resolution models. 3D surface area (cm2) was allometric and estimated from 2D projections using a pre-established relationship. Detailed information on the 2D to 3D conversion can be found in Appendix Figure S3. We extracted information on colony growth, survival and recruitment of Pocillopora populations over the 9-year period using size-thresholds in 3D to distinguish visible recruits (0.4–10 cm2; n = 154), juveniles (10.1–100 cm2; n = 369) and adults (> 100.1 cm2; n = 532). These threshold for visible recruits was determined from the size range of newly appearing individuals from each year from the second year of monitoring. The threshold for juveniles was determined by the maximum size of visible recruits and the minimum size of sexually mature individuals (described in more detail below). These thresholds differentiate sexually immature (visible recruits/juveniles) to mature (adults) individuals, used for ecological interpretation. To identify size-specific relationships of demographic traits associated with reproduction, two nubbins (~5 cm in branch length) were collected from 40 colonies of varying size of P. verrucosa (probably including P. meandrina: 68.2–685.8 cm2 in 3D size) during the reproductive season (April, 2017) at neighbouring Green Island (Lin and Nozawa, 2017). In addition, a further 20 nubbins (of the same size) were collected (68.2–364.7 cm2 in 3D size) to determine the minimum size of sexual maturity at the same time. Nubbins were fixed in a 10% formalin-seawater solution and examined using standard histological methods. Tissue of nubbins were decalcified and dehydrated in an alcohol series using a tissue processor (Thermo Scientific, Excelsior ES, USA) and embedded in paraffin wax (Thermo Scientific Histoplast PE, USA). Samples were then cut with a microtome (Thermo Scientific, Finesse 325) at 6 µm thick intervals. Xylene was used to deparaffin samples and tissue sections were mounted on glass slides, stained with hematoxylin and eosin using a staining machine (Shandon Varistain, Thermo Scientific, USA) and then preserved with Organol/Limonene mounting medium and a glass cover. Sections were examined under a BX51 light microscope (Olympus, Japan). For each nubbin, 2 polyps were haphazardly chosen and the number of oocytes per polyp was determined by observing the entire section of each polyp (a total of 4 polyps per colony). The probability of a colony being reproductively active was determined by the presence or absence of oocytes over colony size.

  6. Colonial Estates South, Stockton, CA, US Demographics 2025

    • point2homes.com
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    Updated 2025
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    Point2Homes (2025). Colonial Estates South, Stockton, CA, US Demographics 2025 [Dataset]. https://www.point2homes.com/US/Neighborhood/CA/Stockton/Colonial-Estates-South.html
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    htmlAvailable download formats
    Dataset updated
    2025
    Dataset authored and provided by
    Point2Homeshttps://plus.google.com/116333963642442482447/posts
    Time period covered
    2025
    Area covered
    South Stockton Street, California, United States
    Variables measured
    Asian, Other, White, 2 units, Over 65, Median age, Blue collar, Mobile home, 3 or 4 units, 5 to 9 units, and 69 more
    Description

    Comprehensive demographic dataset for Colonial Estates South, Stockton, CA, US including population statistics, household income, housing units, education levels, employment data, and transportation with year-over-year changes.

  7. n

    Data from: Population structure, patterns of natal dispersal, and...

    • data.niaid.nih.gov
    zip
    Updated Mar 1, 2022
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    Evelien de Greef; Wesley Brashear; Kira Delmore; Kevin Fraser (2022). Population structure, patterns of natal dispersal, and demographic history in a declining aerial insectivore, the purple martin Progne subis [Dataset]. http://doi.org/10.5061/dryad.gqnk98spz
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    zipAvailable download formats
    Dataset updated
    Mar 1, 2022
    Dataset provided by
    University of Manitoba
    Texas A&M University
    Authors
    Evelien de Greef; Wesley Brashear; Kira Delmore; Kevin Fraser
    License

    https://spdx.org/licenses/CC0-1.0.htmlhttps://spdx.org/licenses/CC0-1.0.html

    Description

    Genetic variation is a fundamental component of biodiversity, and studying population structure, gene flow, and demographic history can help guide conservation strategies for many species. Like other aerial insectivores, the purple martin (Progne subis) is in decline, and yet their genetic background remains largely unknown. To address this knowledge gap, we assessed population structure in the nominate eastern subspecies (P. s. subis) with relation to natal dispersal and examined historical genetic patterns in all three subspecies (P. s. subis, P. s. arboricola, P. s. hesperia) across their North American breeding range by estimating effective population sizes over time. We used next-generation sequencing strategies for genomic analyses, integrating whole-genome resequencing data with continent-wide band encounter records to examine natal dispersal. We documented population structure across P. s. subis, with the highest differentiation between the northern (Alberta) and more southern colonies and following patterns of isolation-by-distance. Consistent with spatial patterns of genetic differentiation, we also found greater longitudinal than latitudinal natal dispersal distances, signifying potential latitudinal constraints on gene flow. Earlier contractions in effective population sizes in the western P. s. arboricola and P. s. hesperia compared to the eastern P. s. subis subspecies suggest these subspecies originated from two different glacial refugia. Together, these findings support latitudinal distinction in P. s. subis, and elucidate the origin of subspecies differentiation, highlighting the importance to conserve populations across the range to maximize genetic diversity and adaptive potential in the purple martin. Methods This dataset contains the unfiltered and filtered single-nucleotide-polymorphisms (SNPs) for 71 purple martins and corresponding code for the filtering process and population analyses. DNA was sequenced through skimSeq low-coverage whole-genome sequencing. The processed dataset has been filtered for quality (QUAL > 20, MQ > 20, MAF > 0.05, missingness < 20%), HWE, bi-allelic, autosomes, and LD-pruned with r2=0.2. Raw sequence reads are available on the Sequence Read Archive (SRA). Additionally included is code for analyzing bird band encounter records (data was obtained from North American Bird Banding Program in May 2019).

  8. White population of the United States 1790, by state and linguistic origin

    • statista.com
    Updated Jul 4, 2024
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    Statista (2024). White population of the United States 1790, by state and linguistic origin [Dataset]. https://www.statista.com/statistics/1360204/us-white-population-linguistic-origin-state-revolutionary-period/
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    Dataset updated
    Jul 4, 2024
    Dataset authored and provided by
    Statistahttp://statista.com/
    Time period covered
    1790
    Area covered
    United States
    Description

    At the end of the Revolutionary Period in United States history, the majority of white settlers in the United States of America had English heritage. The Thirteen Colonies, which claimed independence in 1776, was part of the British Empire until this point - English settlers and their descendants made up over 60 percent of the population by 1790. The English were the ethnic majority (among whites) in all states except Pennsylvania, which had a similarly-sized German population, while New York had a sizeable Dutch population as it was a former Dutch colony. The second-largest group was the Irish, where those from both the island's north and south made up a combined 10 percent of the population, followed by the Scottish and Germans at over eight percent each. Outside of the United States, the French and Spanish territories that would later be incorporated into the Union were majority French and Spanish - despite their large size they were relatively sparsely populated. The composition of the U.S. population would change drastically throughout the 19th century due largely to waves of migration from Europe.

  9. d

    Data from: Environmental and Ecological Regulation of Differences and...

    • search.dataone.org
    Updated Mar 11, 2025
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    Smith, Walker; Tang, Kam (2025). Environmental and Ecological Regulation of Differences and Interactions between Solitary and Colonial Forms of Phaeocystis Antarctica [Dataset]. http://doi.org/10.15784/600043
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    Dataset updated
    Mar 11, 2025
    Dataset provided by
    US Antarctic Program Data Center
    Authors
    Smith, Walker; Tang, Kam
    Area covered
    Description

    Phaeocystis Antarctica is a widely distributed phytoplankton that forms dense blooms and aggregates in the Southern Ocean. This phytoplankton and plays important roles in polar ecology and biogeochemistry, in part because it is a dominant primary producer, a main component of organic matter vertical fluxes, and the principal producer of volatile organic sulfur in the region. Yet P. Antarctica is also one of the lesser known species in terms of its physiology, life history and trophic relationships with other organisms; furthermore, information collected on other Phaeocystis species and from different locations may not be applicable to P. Antarctica in the Ross Sea. P. Antarctica occurs mainly as two morphotypes: solitary cells and mucilaginous colonies, which differ significantly in size, architecture and chemical composition. Relative dominance between solitary cells and colonies determines not only the size spectrum of the population, but also its carbon dynamics, nutrient uptake and utilization. Conventional thinking of the planktonic trophic processes is also challenged by the fact that colony formation could effectively alter the predator-prey interactions and interspecific competition. However, the factors that regulate the differences between solitary and colonial forms of P. Antarctica are not well-understood.

    The research objective of this proposal is therefore to address these over-arching questions: 1. Do P. Antarctica solitary cells and colonies differ in growth, composition and photosynthetic rates? 2. How do nutrients and grazers affect colony development and size distribution of P. Antarctica?
    3. How do nutrients and grazers act synergistically to affect the long-term population dynamics of P. Antarctica?

    Experiments will be conducted in the McMurdo station with natural P. Antarctica assemblages and co-occurring grazers. Laboratory experiments will be conducted to study size-specific growth and photosynthetic rates of P. Antarctica, size-specific grazing mortality due to microzooplankton and mesozooplankton, the effects of macronutrients on the (nitrogen compounds) relative dominance of solitary cells and colonies, and the effects of micronutrient (Fe) and grazing related chemical signals on P. Antarctica colony development. Because this species is of critical importance in the Southern Ocean, and because this research will provide critical information on factors that regulate the role of P.Antarctica in food webs and biogeochemical cycles, a major gap in knowledge will be addressed. This project will train two marine science Ph.D. students. The investigators will also collaborate with the School of Education and a marine science museum to communicate polar science to a broader audience.

  10. d

    Data from: Population structure and phylogeography of the Gentoo Penguin...

    • search.dataone.org
    Updated Apr 1, 2025
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    Hila Levy; Gemma V. Clucas; Alex D. Rogers; Adam D. Leaché; Kate L. Ciborowski; Michael J. Polito; Heather J. Lynch; Michael J. Dunn; Tom Hart (2025). Population structure and phylogeography of the Gentoo Penguin (Pygoscelis papua) across the Scotia Arc [Dataset]. http://doi.org/10.5061/dryad.84c78
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    Dataset updated
    Apr 1, 2025
    Dataset provided by
    Dryad Digital Repository
    Authors
    Hila Levy; Gemma V. Clucas; Alex D. Rogers; Adam D. Leaché; Kate L. Ciborowski; Michael J. Polito; Heather J. Lynch; Michael J. Dunn; Tom Hart
    Time period covered
    Jan 1, 2017
    Description

    Climate change, fisheries pressure on penguin prey, and direct human disturbance of wildlife have all been implicated in causing large shifts in the abundance and distribution of penguins in the Southern Ocean. Without mark-recapture studies, understanding how colonies form and, by extension, how ranges shift is challenging. Genetic studies, particularly focused on newly established colonies, provide a snapshot of colonisation and can reveal the extent to which shifts in abundance and occupancy result from changes in demographic rates (e.g., reproduction and survival) or migration among suitable patches of habitat. Here we describe the population structure of a colonial seabird breeding across a large latitudinal range in the Southern Ocean. Using multilocus microsatellite genotype data from 510 Gentoo penguin (Pygoscelis papua) individuals from 14 colonies along the Scotia Arc and Antarctic Peninsula, together with mitochondrial DNA data, we find strong genetic differentiation between ...

  11. n

    Data from: Dispersal in the sub-Antarctic: king penguins show remarkably...

    • narcis.nl
    Updated Oct 3, 2016
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    Clucas, Gemma V.; Younger, Jane L.; Kao, Damian; Rogers, Alex D.; Handley, Jonathan; Miller, Gary D.; Jouventin, Pierre; Nolan, Paul; Gharbi, Karim; Miller, Karen J.; Hart, Tom (2016). Data from: Dispersal in the sub-Antarctic: king penguins show remarkably little population genetic differentiation across their range [Dataset]. http://doi.org/10.5061/dryad.7c0q8
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    Dataset updated
    Oct 3, 2016
    Dataset provided by
    Data Archiving and Networked Services (DANS)
    Authors
    Clucas, Gemma V.; Younger, Jane L.; Kao, Damian; Rogers, Alex D.; Handley, Jonathan; Miller, Gary D.; Jouventin, Pierre; Nolan, Paul; Gharbi, Karim; Miller, Karen J.; Hart, Tom
    Description

    Background: Seabirds are important components of marine ecosystems, both as predators and as indicators of ecological change, being conspicuous and sensitive to changes in prey abundance. To determine whether fluctuations in population sizes are localised or indicative of large-scale ecosystem change, we must first understand population structure and dispersal. King penguins are long-lived seabirds that occupy a niche across the sub-Antarctic zone close to the Polar Front. Colonies have very different histories of exploitation, population recovery, and expansion. Results: We investigated the genetic population structure and patterns of colonisation of king penguins across their current range using a dataset of 5154 unlinked, high-coverage single nucleotide polymorphisms generated via restriction site associated DNA sequencing (RADSeq). Despite breeding at a small number of discrete, geographically separate sites, we find only very slight genetic differentiation among colonies separated by thousands of kilometers of open-ocean, suggesting migration among islands and archipelagos may be common. Our results show that the South Georgia population is slightly differentiated from all other colonies and suggest that the recently founded Falkland Island colony is likely to have been established by migrants from the distant Crozet Islands rather than nearby colonies on South Georgia, possibly as a result of density-dependent processes. Conclusions: The observed subtle differentiation among king penguin colonies must be considered in future conservation planning and monitoring of the species, and demographic models that attempt to forecast extinction risk in response to large-scale climate change must take into account migration. It is possible that migration could buffer king penguins against some of the impacts of climate change where colonies appear panmictic, although it is unlikely to protect them completely given the widespread physical changes projected for their Southern Ocean foraging grounds. Overall, large-scale population genetic studies of marine predators across the Southern Ocean are revealing more interconnection and migration than previously supposed.

  12. n

    Breeding populations of Southern Giant Petrels at Heard Island, the McDonald...

    • cmr.earthdata.nasa.gov
    Updated Apr 10, 2019
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    (2019). Breeding populations of Southern Giant Petrels at Heard Island, the McDonald Islands and within the AAT [Dataset]. https://cmr.earthdata.nasa.gov/search/concepts/C1214311327-AU_AADC
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    Dataset updated
    Apr 10, 2019
    Time period covered
    Jan 1, 1955 - Dec 31, 2002
    Area covered
    Description

    This indicator is no longer maintained, and is considered OBSOLETE.

    INDICATOR DEFINITION The number of breeding pairs of Southern Giant Petrels at Heard Island, the McDonald Islands, and in colonies near Casey, Davis and Mawson stations.

    TYPE OF INDICATOR There are three types of indicators used in this report: 1. Describes the CONDITION of important elements of a system; 2. Show the extent of the major PRESSURES exerted on a system; 3. Determine RESPONSES to either condition or changes in the condition of a system.

    This indicator is one of: CONDITION

    RATIONALE FOR INDICATOR SELECTION The breeding population of Southern Giant Petrels is related to resource availability (nesting space and food), behavioural mechanisms (immigration/emigration and breeding effort/success) in addition to climate change and human impacts (including fisheries and human disturbance). Monitoring breeding populations and interpretation of the data provides information on changes in the Antarctic and Subantarctic ecosystems.

    DESIGN AND STRATEGY FOR INDICATOR MONITORING PROGRAM Spatial scale: Colonies near Australian Stations - Frazier Islands, Casey (lat 66 degrees 16' 54.5' S, long 110 degrees 31' 39.4' E) Hawker Island, Davis (lat 68 degrees 34' 35.8' S, long 77 degrees 58' 02.6' E) Giganteus Island, Mawson (lat 67 degrees 36' 09.7' S, long 62 degrees 52' 25.7' E)

    Heard Island - (lat 53 degrees 06' 00.0' S, long 73 degrees 31' 59.9' E)

    McDonald Islands - (lat 53 degrees 02' 26.2' S, long 72 degrees 36' 00.0' E)

    Frequency: Breeding Southern Giant Petrels are easily disturbed. Colonies are visited every 3-5 years to minimise disturbance to breeding birds.

    Measurement technique: All colonies are visited and breeding birds are counted from outside the colonies by two personnel performing replicate counts. All breeding individuals in a colony are counted. No birds are disturbed off their nests.

    Considerations regarding disturbance associated with census visits are also incorporated into monitoring strategies. The lack of annual census data does not reduce the value of these long-term monitoring programmes.

    RESEARCH ISSUES All Southern Giant Petrel breeding populations in the AAT and at HIMI decreased following their discovery. Southern Giant Petrels breeding on Indian Ocean islands are highly sensitive to human disturbance. Access to breeding colonies is restricted, as are the types of activities permitted. Disturbance from researchers has been implicated in the observed decreases in these populations (Woehler et al. 2001, Woehler et al. in press). Analyses of the long term AAT data suggest that the breeding populations at Hawker Is and at the Frazier Is have recovered following the restrictions on access and activities permitted on breeding islands.

    LINKS TO OTHER INDICATORS

  13. n

    Data from: Reduced representation sequencing detects only subtle regional...

    • data.niaid.nih.gov
    zip
    Updated Aug 10, 2019
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    Nicolas Dussex; Helen R. Taylor; Willam R. Stovall; Kim Rutherford; Ken G. Dodds; Shannon M. Clarke; Neil J. Gemmell (2019). Reduced representation sequencing detects only subtle regional structure in a heavily exploited and rapidly recolonizing marine mammal species [Dataset]. http://doi.org/10.5061/dryad.63nm407
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    zipAvailable download formats
    Dataset updated
    Aug 10, 2019
    Dataset provided by
    University of Otago
    AgResearch
    Authors
    Nicolas Dussex; Helen R. Taylor; Willam R. Stovall; Kim Rutherford; Ken G. Dodds; Shannon M. Clarke; Neil J. Gemmell
    License

    https://spdx.org/licenses/CC0-1.0.htmlhttps://spdx.org/licenses/CC0-1.0.html

    Area covered
    New Zealand
    Description

    Next‐generation reduced representation sequencing (RRS) approaches show great potential for resolving the structure of wild populations. However, the population structure of species that have shown rapid demographic recovery following severe population bottlenecks may still prove difficult to resolve due to high gene flow between subpopulations. Here, we tested the effectiveness of the RRS method Genotyping‐By‐Sequencing (GBS) for describing the population structure of the New Zealand fur seal (NZFS, Arctocephalus forsteri), a species that was heavily exploited by the 19th century commercial sealing industry and has since rapidly recolonized most of its former range from a few isolated colonies. Using 26,026 neutral single nucleotide polymorphisms (SNPs), we assessed genetic variation within and between NZFS colonies. We identified low levels of population differentiation across the species range (<1% of variation explained by regional differences) suggesting a state of near panmixia. Nonetheless, we observed subtle population substructure between West Coast and Southern East Coast colonies and a weak, but significant (p = 0.01), isolation‐by‐distance pattern among the eight colonies studied. Furthermore, our demographic reconstructions supported severe bottlenecks with potential 10‐fold and 250‐fold declines in response to Polynesian and European hunting, respectively. Finally, we were able to assign individuals treated as unknowns to their regions of origin with high confidence (96%) using our SNP data. Our results indicate that while it may be difficult to detect population structure in species that have experienced rapid recovery, next‐generation markers and methods are powerful tools for resolving fine‐scale structure and informing conservation and management efforts.

  14. a

    Antarctic Fur Seal Populations on Heard Island Summer 1987-1988

    • data.aad.gov.au
    Updated Oct 7, 1999
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    GOLDSWORTHY, SIMON (1999). Antarctic Fur Seal Populations on Heard Island Summer 1987-1988 [Dataset]. http://doi.org/10.26179/fdqh-cd64
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    Dataset updated
    Oct 7, 1999
    Dataset provided by
    Australian Antarctic Data Centre
    Authors
    GOLDSWORTHY, SIMON
    License

    Attribution 4.0 (CC BY 4.0)https://creativecommons.org/licenses/by/4.0/
    License information was derived automatically

    Time period covered
    Nov 25, 1987 - Feb 25, 1988
    Area covered
    Description

    Abstract from ANARE Research Notes 72 The Antarctic fur seal Arctocephalus gazella has increased in numbers at Heard Island since the Australian National Antarctic Research Expeditions (ANARE) station was established in 1947. Increases have also been recorded at other breeding sites in the South Atlantic and South Indian Oceans this century, particularly at South Georgia.

    In the 1987-88 summer, fur seals at Heard Island were counted in several age and sex categories. The aims of the project were to determine the location of pupping sites, the extent of the pupping season and the size of the population, and to record the changes in numbers of animals ashore during the summer. Maps of the colonies and main haul-out areas, together with descriptions of census areas and tabulations of counts, provide a basis for future comparison.

    This dataset contains the results from surveys of Antarctic Fur Seals (Arctocephalus gazella) on Heard Island during the summer of 1987-1988. As well as habitat descriptions, age, sex, count of adults and pups were determined. The three major aims of the study include: to determine accurately the location of pupping sites; to determine the extent of the pupping season, the median date of birth and the number of pups born; and to census fur seals on as much of the island as possible in order to determine the number of animals ashore and to document changes in numbers during the summer. The results are listed in the document, which includes detailed tabulations of counts made at colonies and major haul-out sites on Macquarie Island during summer 1987-88, and descriptions and maps of these locations. Tagging, mainly of pups, was also undertaken, and a total of 234 pups, 8 under-yearlings, 9 yearlings, 2 juveniles and 1 sub-adult male were tagged. Counts at 3-day intervals (pups) were made between 25 November and 19 December 1987, and major censuses were made between 19 December 1987 and 25 February 1988.

    The fields in this dataset are: Locality Age Class Date Colony Bulls Cows Pups

  15. Data from: Geographic patterns in colonial reproductive strategy in...

    • zenodo.org
    bin
    Updated Jun 3, 2022
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    Adam Cronin; Adam Cronin; Noriko Azuma; Satoshi Miyazaki; Emiko Oguri; Michael Schwarz; Fuminori Ito; Noriko Azuma; Satoshi Miyazaki; Emiko Oguri; Michael Schwarz; Fuminori Ito (2022). Data from: Geographic patterns in colonial reproductive strategy in Myrmecina nipponica: links between biogeography and a key polymorphism in ants [Dataset]. http://doi.org/10.5061/dryad.9w0vt4bc5
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    binAvailable download formats
    Dataset updated
    Jun 3, 2022
    Dataset provided by
    Zenodohttp://zenodo.org/
    Authors
    Adam Cronin; Adam Cronin; Noriko Azuma; Satoshi Miyazaki; Emiko Oguri; Michael Schwarz; Fuminori Ito; Noriko Azuma; Satoshi Miyazaki; Emiko Oguri; Michael Schwarz; Fuminori Ito
    License

    CC0 1.0 Universal Public Domain Dedicationhttps://creativecommons.org/publicdomain/zero/1.0/
    License information was derived automatically

    Description

    The ability to express different phenotypes can help define species distributions by allowing access to, and exploitation of, new environments. Social insects employ two markedly different reproductive strategies with contrasting cost/benefit characteristics: independent colony foundation (ICF), which is associated with high dispersal range and high risk, and dependent colony foundation (DCF), characterized by low risk but low dispersal. The ant Myrmecina nipponica employs both of these strategies, with the frequency of each apparently varying between populations. We combine molecular data with data on reproductive strategy from different populations of this species throughout Japan to explore how this polymorphism is linked to environmental factors and if this relationship can help explain the current and historical biogeography of this species. Reproductive strategy exhibited a strong geographic pattern, with ICF predominant in southern populations and DCF more common in northern and southern highland populations. Molecular analyses clearly divided populations into broad geographic regions, with the southern-lowland populations basal to (southern-highland (+ northern)) populations. Intra-population polymorphism in colony founding strategy was widespread, and polymorphism was reconstructed as the likely ancestral state. The frequency of different strategies was linked with climate, with DCF more common in colder areas. A recent inferred origin to the northern lineage suggests that colonization of northern Japan was a rapid event coincident with warming at the end of the last glacial maxima, likely facilitated by the cold-adaptive advantages of DCF. We discuss how such polymorphisms could help explain the biogeography of this and other social insects.

  16. Population of the United States 1500-2100

    • statista.com
    Updated Aug 1, 2025
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    Statista (2025). Population of the United States 1500-2100 [Dataset]. https://www.statista.com/statistics/1067138/population-united-states-historical/
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    Dataset updated
    Aug 1, 2025
    Dataset authored and provided by
    Statistahttp://statista.com/
    Area covered
    United States
    Description

    In the past four centuries, the population of the Thirteen Colonies and United States of America has grown from a recorded 350 people around the Jamestown colony in Virginia in 1610, to an estimated 346 million in 2025. While the fertility rate has now dropped well below replacement level, and the population is on track to go into a natural decline in the 2040s, projected high net immigration rates mean the population will continue growing well into the next century, crossing the 400 million mark in the 2070s. Indigenous population Early population figures for the Thirteen Colonies and United States come with certain caveats. Official records excluded the indigenous population, and they generally remained excluded until the late 1800s. In 1500, in the first decade of European colonization of the Americas, the native population living within the modern U.S. borders was believed to be around 1.9 million people. The spread of Old World diseases, such as smallpox, measles, and influenza, to biologically defenseless populations in the New World then wreaked havoc across the continent, often wiping out large portions of the population in areas that had not yet made contact with Europeans. By the time of Jamestown's founding in 1607, it is believed the native population within current U.S. borders had dropped by almost 60 percent. As the U.S. expanded, indigenous populations were largely still excluded from population figures as they were driven westward, however taxpaying Natives were included in the census from 1870 to 1890, before all were included thereafter. It should be noted that estimates for indigenous populations in the Americas vary significantly by source and time period. Migration and expansion fuels population growth The arrival of European settlers and African slaves was the key driver of population growth in North America in the 17th century. Settlers from Britain were the dominant group in the Thirteen Colonies, before settlers from elsewhere in Europe, particularly Germany and Ireland, made a large impact in the mid-19th century. By the end of the 19th century, improvements in transport technology and increasing economic opportunities saw migration to the United States increase further, particularly from southern and Eastern Europe, and in the first decade of the 1900s the number of migrants to the U.S. exceeded one million people in some years. It is also estimated that almost 400,000 African slaves were transported directly across the Atlantic to mainland North America between 1500 and 1866 (although the importation of slaves was abolished in 1808). Blacks made up a much larger share of the population before slavery's abolition. Twentieth and twenty-first century The U.S. population has grown steadily since 1900, reaching one hundred million in the 1910s, two hundred million in the 1960s, and three hundred million in 2007. Since WWII, the U.S. has established itself as the world's foremost superpower, with the world's largest economy, and most powerful military. This growth in prosperity has been accompanied by increases in living standards, particularly through medical advances, infrastructure improvements, clean water accessibility. These have all contributed to higher infant and child survival rates, as well as an increase in life expectancy (doubling from roughly 40 to 80 years in the past 150 years), which have also played a large part in population growth. As fertility rates decline and increases in life expectancy slows, migration remains the largest factor in population growth. Since the 1960s, Latin America has now become the most common origin for migrants in the U.S., while immigration rates from Asia have also increased significantly. It remains to be seen how immigration restrictions of the current administration affect long-term population projections for the United States.

  17. Variation in population size, nest distribution, colony extent, and timing...

    • data.niaid.nih.gov
    zip
    Updated Aug 30, 2024
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    Juan Masello; Lena Gonther; Mauricio Failla; Heike Wemhoff-de Groot; Fabián Llanos; Christina Sommer; Roger Mundry; Verónica Seijas; Petra Quillfeldt (2024). Variation in population size, nest distribution, colony extent, and timing of movements at the largest known parrot colony [Dataset]. http://doi.org/10.5061/dryad.1ns1rn93f
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    zipAvailable download formats
    Dataset updated
    Aug 30, 2024
    Dataset provided by
    Bielefeld University
    German Primate Center
    Justus-Liebig-Universität Gießen
    Institute of Avian Research
    Proyecto Patagonia Noreste, Balneario El Cóndor, Río Negro, Argentina
    Secretaría de Ambiente y Cambio Climático, Gobierno de Río Negro, Viedma, Río Negro, Argentina
    M.E.E.R. e.V., Berlin, Germany
    Authors
    Juan Masello; Lena Gonther; Mauricio Failla; Heike Wemhoff-de Groot; Fabián Llanos; Christina Sommer; Roger Mundry; Verónica Seijas; Petra Quillfeldt
    License

    https://spdx.org/licenses/CC0-1.0.htmlhttps://spdx.org/licenses/CC0-1.0.html

    Description

    Psittaciformes are among the most threatened birds, and population size and trend estimates are needed to aid conservation. The burrowing parrot (Cyanoliseus patagonus) is undergoing substantial changes in its population size, due to habitat degradation, trapping for the pet trade, and persecution as a crop pest. The species formerly had several large colonies, but these were severely reduced during a program of agriculture pest control. Currently, only one large colony remains, together with a decreasing number of smaller colonies spread throughout the Monte and adjacent ecoregions. The colony at El Cóndor, north-eastern Patagonia, Argentina, is of particular importance, concentrating 71% of the global breeding population of burrowing parrots. We aimed to determine changes in 1) breeding population size, 2) the extent of the colony, 3) the distribution of nests along the colony, and 4) the timing of movements from the nest to the foraging locations during the breeding season, over our long-term study (1998-2019). We found that the number of active nests declined from 37531 in 2001 to 21883 in 2005, and recovered in the following years, reaching 40671 nests in 2019. The decline observed in 2005 could be related to droughts and associated food shortage during the La Niña phase of El Niño Southern Oscillation. The colony expanded westwards, from 9 km length in 2001, to 18.1 km in 2019. During the same period, the part of the colony with the highest number of active nests shifted 5 km westwards from El Cóndor village. Both changes could be the consequence of human disturbance. As any serious threat affecting this colony could have severe consequences for the survival of the species, regular monitoring is needed, together with legal protection of the burrowing parrot colony at El Cóndor and the Monte ecosystem around it. Methods The dataset consist of photographs taken at the burrowing parrot Cyanoliseus patagonus colony at El Cóndor, village, adjacent to the estuary of the Río Negro in Río Negro, north-eastern Patagonia, Argentina, from 2001 to 2019. During the earlier years of current study (breeding seasons 2004-2005, and 2005-2006), we followed the methodology of Masello et al. (2006) to estimate of the breeding population size of El Cóndor colony (breeding season 2001-2002, hereafter 2001). We photographed the entirety of the densest part of the colony (easternmost; Table 1). This is a part of the cliff, up to 27 m high, where soft sandstone layers belonging to the Río Negro geological formation make the entire cliff. In this part of the colony, the parrots dig their nests between 3 and 26.5 m above sea level. However, for the westernmost part of the colony, sample photographs were taken every 450 m, and the total number of nests in the 450-m sector was extrapolated from these photographs (Masello et al. 2006). In more recent years (breeding seasons 2007-2008, 2008-2009, and 2019-2020), following advances in digital photography, we took a continuous series of digital photographs (3000 x 4000 pixels) covering the entire colony. This means, that the nest counts for those later years represent a complete census of the colony. We took all photographs of the Burrowing Parrot colony from the sandy beach exposed at the bottom of the cliff during low tide. The colony is accessible from its easternmost end (kilometre 1), and from three man-made accesses cut in the cliff and situated at the easternmost part of kilometre 2 (car access called ‘Segunda Bajada del Faro’), in kilometre 15 (pedestrian access, ‘El Espigón’), and at the easternmost part of kilometre 17 (pedestrian access, ‘Playa Bonita’). Using those accesses, we were able to walk along the cliff, from the vicinity of El Cóndor village to up to three kilometres past the pedestrian access at kilometre 17; thus, we were able to survey the entire Burrowing Parrot colony. During low tide, we were able to shoot photographs from 150 to 170 m away from the cliff. This, resulted in larger sector of the cliff included in each photograph (approximately 200 m). During high tide, we had to take the photographs closer to the cliff (40 to 50 m), resulting in shorter sectors being captured per photograph (approximately 50 m). Due to the sheer size of the colony, we took the photographs over four to five days of fieldwork during each studied season. For this reason, the photographs show small differences in illumination. To minimize such differences, and to avoid strong shadows that could create false structures in the images, we took the photographs during overcast days. Masello, J.F., Pagnossin, M.L., Sommer, C., Quillfeldt, P. 2006. Population size, provisioning frequency, flock size and foraging range at the largest known colony of Psittaciformes: the Burrowing Parrots of the north-eastern Patagonian coastal cliffs. Emu, 106: 69-79.

  18. f

    Breeding data of little penguins collected at ten colonies in South...

    • open.flinders.edu.au
    txt
    Updated Jun 9, 2023
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    Bianca Johnson; Diane Colombelli-Negrel (2023). Breeding data of little penguins collected at ten colonies in South Australia between 1990 and 2018 [Dataset]. http://doi.org/10.25957/dyv5-4a64
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    txtAvailable download formats
    Dataset updated
    Jun 9, 2023
    Dataset provided by
    Flinders University
    Authors
    Bianca Johnson; Diane Colombelli-Negrel
    License

    Attribution 4.0 (CC BY 4.0)https://creativecommons.org/licenses/by/4.0/
    License information was derived automatically

    Area covered
    South Australia, Australia
    Description

    As bio-indicators, seabirds across the globe help us understand how our environment is changing, and how this is affecting our wildlife. Little penguins (Eudyptula minor) in Australia are a key species in understanding the changes to the Australian environment. However, studies generally focus on the effects of oceanic changes without always accounting for the potential interactions with the environmental conditions experienced on land during breeding. This study examined the relationships between both marine and terrestrial environmental variables and breeding success in South Australian little penguins, observing ten colonies over a non-consecutive 28-year time period. Our results showed that South Australian little penguins had a lower breeding success (fewer fledglings produced per pair) when sea surface temperatures were higher in the three months before breeding and when high winds occurred during the breeding season. We also observed local variation between the colonies: breeding success was only influenced by environmental variables for colonies located near open waters and not for colonies located in enclosed bays. These results confirms the idea that future oceanographic warming is expected to reduce the breeding success (and population size) of some Australian seabirds, including little penguins.Date coverage: 1990 - 2018

  19. f

    Data from: Uncovering population structure in the Humboldt penguin...

    • datasetcatalog.nlm.nih.gov
    Updated May 10, 2019
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    Luna-Jorquera, Guillermo; Dantas, Gisele P. M.; González-Acuña, Daniel; Vianna, Juliana A.; Santos, Amanda M.; Valdés-Velásquez, Armando; Oliveira, Larissa R.; Morgante, João S.; Simeone, Alejandro; Le Bohec, Céline; Cardeña, Marco; de Melo, Daniella R.; Flores, Mariana D. (2019). Uncovering population structure in the Humboldt penguin (Spheniscus humboldti) along the Pacific coast at South America [Dataset]. https://datasetcatalog.nlm.nih.gov/dataset?q=0000093961
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    Dataset updated
    May 10, 2019
    Authors
    Luna-Jorquera, Guillermo; Dantas, Gisele P. M.; González-Acuña, Daniel; Vianna, Juliana A.; Santos, Amanda M.; Valdés-Velásquez, Armando; Oliveira, Larissa R.; Morgante, João S.; Simeone, Alejandro; Le Bohec, Céline; Cardeña, Marco; de Melo, Daniella R.; Flores, Mariana D.
    Area covered
    West Coast of the United States
    Description

    The upwelling hypothesis has been proposed to explain reduced or lack of population structure in seabird species specialized in food resources available at cold-water upwellings. However, population genetic structure may be challenging to detect in species with large population sizes, since variation in allele frequencies are more robust under genetic drift. High gene flow among populations, that can be constant or pulses of migration in a short period, may also decrease power of algorithms to detect genetic structure. Penguin species usually have large population sizes, high migratory ability but philopatric behavior, and recent investigations debate the existence of subtle population structure for some species not detected before. Previous study on Humboldt penguins found lack of population genetic structure for colonies of Punta San Juan and from South Chile. Here, we used mtDNA and nuclear markers (10 microsatellites and RAG1 intron) to evaluate population structure for 11 main breeding colonies of Humboldt penguins, covering the whole spatial distribution of this species. Although mtDNA failed to detect population structure, microsatellite loci and nuclear intron detected population structure along its latitudinal distribution. Microsatellite showed significant Rst values between most of pairwise locations (44 of 56 locations, Rst = 0.003 to 0.081) and 86% of individuals were assigned to their sampled colony, suggesting philopatry. STRUCTURE detected three main genetic clusters according to geographical locations: i) Peru; ii) North of Chile; and iii) Central-South of Chile. The Humboldt penguin shows signal population expansion after the Last Glacial Maximum (LGM), suggesting that the genetic structure of the species is a result of population dynamics and foraging colder water upwelling that favor gene flow and phylopatric rate. Our findings thus highlight that variable markers and wide sampling along the species distribution are crucial to better understand genetic population structure in animals with high dispersal ability.

  20. n

    Abandoned Elephant Seal Colonies in Antarctica: Integration of Genetic,...

    • cmr.earthdata.nasa.gov
    Updated Nov 15, 2020
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    (2020). Abandoned Elephant Seal Colonies in Antarctica: Integration of Genetic, Isotopic, and Geologic Approaches toward Understanding Holocene Environmental Change [Dataset]. https://cmr.earthdata.nasa.gov/search/concepts/C2532069615-AMD_USAPDC.html
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    Dataset updated
    Nov 15, 2020
    Time period covered
    Sep 15, 2005 - Aug 31, 2009
    Area covered
    Description

    During previous NSF-sponsored research, the PI's discovered that southern elephant seal colonies once existed along the Victoria Land coast (VLC) of Antarctica, a region where they are no longer observed. Molted seal skin and hair occur along 300 km of coastline, more than 1000 km from any extant colony. The last record of a seal at a former colony site is at ~A.D. 1600. Because abandonment occurred prior to subantarctic sealing, disappearance of the VLC colony probably was due to environmental factors, possibly cooling and encroachment of land-fast, perennial sea ice that made access to haul-out sites difficult. The record of seal inhabitation along the VLC, therefore, has potential as a proxy for climate change. Elephant seals are a predominantly subantarctic species with circumpolar distribution. Genetic studies have revealed significant differentiation among populations, particularly with regard to that at Macquarie I., which is the extant population nearest to the abandoned VLC colony. Not only is the Macquarie population unique genetically, but it is has undergone unexplained decline of 2%/yr over the last 50 years3. In a pilot study, genetic analyses showed a close relationship between the VLC seals and those at Macquarie I. An understanding of the relationship between the two populations, as well as of the environmental pressures that led to the demise of the VLC colonies, will provide a better understanding of present-day population genetic structure, the effect of environmental change on seal populations, and possibly the reasons underlying the modern decline at Macquarie Island. This project addresses several key research problems: (1) Why did elephant seals colonize and then abandon the VLC? (2) What does the elephant seal record reveal about Holocene climate change and sea-ice conditions? (3) What were the foraging strategies of the seals and did these strategies change over time as climate varied? (4) How does the genetic structure of the VLC seals relate to extant populations? (5) How did genetic diversity change over time and with colony decline? (6) Using ancient samples to estimate mtDNA mutation rates, what can be learned about VLC population dynamics over time? (7) What was the ecological relationship between elephant seals and Adelie penguins that occupied the same sites, but apparently at different times? The proposed work includes the professional training of young researchers and incorporation of data into graduate and undergraduate courses.

    Because of extreme isolation of the Antarctic continent since the
    Early Oligocene, one expects a unique invertebrate benthic fauna with
    a high degree of endemism. Yet some invertebrate taxa that constitute
    important ecological components of sedimentary benthic communities
    include more than 40 percent non-endemic species (e.g., benthic
    polychaetes). To account for non-endemic species, intermittent genetic
    exchange must occur between Antarctic and other (e.g. South American)
    populations. The most likely mechanism for such gene flow, at least
    for in-faunal and mobile macrobenthos, is dispersal of planktonic
    larvae across the sub- Antarctic and Antarctic polar fronts. To test
    for larval dispersal as a mechanism of maintaining genetic continuity
    across polar fronts, the scientists propose to (1) take plankton
    samples along transects across Drake passage during both the austral
    summer and winter seasons while concurrently collecting the
    appropriate hydrographic data. Such data will help elucidate the
    hydrographic mechanisms that allow dispersal across Drake Passage.
    Using a molecular phylogenetic approach, they will (2) compare
    seemingly identical adult forms from Antarctic and South America
    continents to identify genetic breaks, historical gene flow, and
    control for the presence of cryptic species. (3) Similar molecular
    tools will be used to relate planktonic larvae to their adult forms.
    Through this procedure, they propose to link the larval forms
    respectively to their Antarctic or South America origins. The proposed
    work builds on previous research that provides the basis for this
    effort to develop a synthetic understanding of historical gene flow
    and present day dispersal mechanism in South American/Drake Passage/ Antarctic Peninsular region. Furthermore, this work represents one of
    the first attempts to examine recent gene flow in Antarctic benthic
    invertebrates. Graduate students and a postdoctoral fellow will be
    trained during this research

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Statista (1999). Thirteen Colonies: southern colonies population by ethnicity and state 1620-1760 [Dataset]. https://www.statista.com/statistics/1415538/thirteen-colonies-southern-colonies-pop-ethnicity-state/
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Thirteen Colonies: southern colonies population by ethnicity and state 1620-1760

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Dataset updated
Jan 1, 1999
Dataset authored and provided by
Statistahttp://statista.com/
Area covered
United States
Description

The Colony of Virginia, the location of the Jamestown Settlement (the first permanent English settlement in the Americas), was the most populous southern colony or state in the region until it was partitioned into Virginia and West Virginia during the American Civil War. Virginia was also the most populous of the Thirteen Colonies throughout most of the Colonial Era. In terms of ethnicity, the southern colonies had the largest relative Black populations, with South Carolina even becoming majority-Black in the 1710s.

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