Abstract

The MxFLS is the first longitudinal survey in Mexico that follows individuals across rounds, including those who migrate within Mexico or emigrate to the Unites States of America. This allows studying the well-being of the Mexican population, and its transitions over time, as well as the factors that determine those transitions. Given that the MxFLS provides information for individuals who emigrated to the USA, it is possible to study, for the first time, migration dynamics between Mexico and the USA.

A primary goal of the Mexican Family Life Survey (MxFLS) is to create a longitudinal and multi-thematic database. On the one hand, this allows a long term tracking of individuals regardless of change in residence, newly formed homes or home conversions; and on the other hand, these characteristics will be beneficial in their use of a single tool collecting economic, demographic and health population indicators of the Mexican population. The survey’s first round (MxFLS-1) took place during the year 2002 reaching a sample size of 35 thousand individual interviews in 150 urban and rural locations throughout the country. The second round (MxFLS-2) ended during 2006 with 90 per cent a re-contact rate at the household level. During this second operational phase of tracking and interviewing original households between 2002 and 2006, those who migrated to the United States were contacted at a rate of over 91 per cent. Within this content, MxFLS-2 provides statistical evidence on the flow of internal migration into the United States, on population and on the welfare dynamics of the Mexican people that relocate within the country and in the US. This is regardless of whether or not they remain or return to their national territory and/or community of origin.

The MxFLS provides data to analyze the well-being of the Mexican population, and its transitions over time, as well as the factors that determine those transitions.

Geographic coverage

National coverage

Analysis unit

• Household
• Individual
• Community

Kind of data

Sample survey data [ssd]

Sampling procedure

Sampling design The design of the first round, the baseline survey (MxFLS-1), was undertaken by the National Institute of Statistics and Geography (INEGI, per its name in Spanish). The baseline sample is probabilistic, stratified, multi-staged, and independent at every phase of the study. The population is comprised by Mexican households in 2002. Primary sampling units were selected under criterions of national, urban-rural and regional representation on pre-established demographic and economic variables. Regional definitions are in accordance with the National Development Plan 2000-2006.

Longitudinal design The first round or baseline survey (MXFLS-1), implemented in 2002, and collected information on a sample of 35,000 individuals from 8,400 households in 150 communities throughout the country. The second (MxFLS-2) was conducted during 2005-2006. Given the longitudinal design of the survey, the MxFLS-2 aimed to relocate and re-interview the sample of the MxFLS-1-including those individuals who migrated within Mexico or emigrated to the United States of America-and to interview the individuals or households that grew out from previous samples. The MxFLS-2 relocated and re-interviewed almost 90 percent of the original sampled households.

Mode of data collection

Face-to-face [f2f]

Research instrument

The 2005 MxFLS-2 follows the content, design and structure of MxFLS-1 questionnaires. Additionally, MxFLS-2 contains innovative modules collecting data on child upbringing, individual expectations, seasonal preferences, altruistic behavior and risk taking.

This dataset contains genomic records from 184 California Gnatcatchers (Polioptila californica) collected at 18 sites in southern California (USA), 13 sites in Baja California (Mexico), and 17 sites in Baja California Sur (Mexico). Genomic markers were generated from ddRAD loci (Peterson and others, 2012) and analyzed using the Stacks v2.53 (Catchen and others, 2013) pipeline. The genotypes for all samples are provided in a VCF file with 84,125 independent loci and 7 percent missing data. A companion file is provided with sample names and occurrence designations. These files may be opened and edited in a text editor program, such as Notepad (PC) or BBEdit (Mac). The .vcf file can be loaded into the Stacks population program (Catchen and others, 2013) to calculate genetic diversity statistics, or loaded into R, using vcfR (Knaus and Grunwald, 2017), for further analysis. References: Catchen J., Hohenlohe P.A., Bassham S., Amores A., Cresko W.A. Stacks-an analysis tool set for population genomics. Molecular Ecology. 2013; 22:3124-3140. Knaus, B.J, Grunwald N.J. vcfr: a package to manipulate and visualize variant call format data in R. Molecular Ecology Resources. 2016; 17:44-53. Peterson B.K., Weber J.N., Kay E.H., Fisher H.S., Hoekstra H.E. Double Digest RADseq-an inexpensive method for de novo SNP discovery and genotyping in model and non-model species: PLoS ONE. 2012; 7:e37135.

Climate change and the northern elephant seal (Mirounga angustirostris) population in Baja California, Mexico - Table 1

AbstractThe prevalence of disease-driven mass mortality events is increasing, but our understanding of spatial variation in their magnitude, timing, and triggers are often poorly resolved. Here, we use a novel range-wide dataset comprised of 48,810 surveys to quantify how Sea Star Wasting Disease affected Pycnopodia helianthoides, the sunflower sea star, across its range from Baja California, Mexico to the Aleutian Islands, USA. We found that the outbreak occurred more rapidly, killed a greater percentage of the population, and left fewer survivors in the southern half of the species’ range. Pycnopodia now appears to be functionally extinct (> 99.2% declines) from Baja California, Mexico to Cape Flattery, Washington, USA and exhibited severe declines (> 87.8%) from the Salish Sea to the Gulf of Alaska. The importance of temperature in predicting Pycnopodia distribution rose 450% after the outbreak, suggesting these latitudinal gradients may stem from an interaction between disease severity and warmer waters. We found no evidence of population recovery in the years since the outbreak. Natural recovery in the southern half of the range is unlikely over the short-term and assisted recovery will likely be required for recovery in the southern half of the range on ecologically-relevant time scales. MethodsThirty research groups from Canada, the United States, Mexico, including First Nations, shared 34 datasets containing field surveys of Pycnopodia (Table S1). The data included 48,810 surveys from 1967 to 2020 derived from trawls, remotely operated vehicles, SCUBA dives, and intertidal surveys. We compiled survey data into a standardized format that included at minimum the coordinates, date, depth, area surveyed, and occurrence of Pycnopodia for each survey. When datasets contained more than one survey at a site in the same day (e.g. multiple transects), we divided the total Pycnopodia count in all surveys by the total survey area and averaged the latitude, longitude, and depth as necessary. Using breaks in data coverage, political boundaries, and biogeographic breaks we assigned each survey to one of twelve regions: Aleutian Islands, west Gulf of Alaska (GOA), east Gulf of Alaska, southeast Alaska, British Columbia (excluding the Salish Sea), Salish Sea (including the Puget Sound), Washington outer coast (excluding the Puget Sound), Oregon, northern California, central California, southern California, and the Pacific coast of Baja California (Fig. S1; see Supplementary Material). Usage notesDocumentation, data, and code accompanying Hamilton et al., 2021 Pycnopodia Rangewide Assessment paper. Data MasterPycno_ToShare: Dec_lat = latitude in decimal degrees. Numeric. Dec_lon = longitude in decimal degrees. Numeric. Depth = depth in meters. Numeric. Pres_abs = presence or absence of Pycnopodia on that survey. Binary. Presence = 1, absence = 0 Density_m2 = density in meters squared if available for that set of surveys. Numeric. NA = no density data available for that survey. Source = shorthand name of the group that shared the data with us and the type of data (e.g. trawl, dive). To get further info on who that dataset, group, and group contact, see Table S1. Character. Note: When datasets contained more than one survey at a site in the same day (e.g. multiple transects), we divided the total Pycnopodia count in all surveys by the total survey area and averaged the latitude, longitude, and depth as necessary in order to minimize the impacts of pseudoreplication on the dataset. Used in MaxentSWD_Final and Density-Inc_Models_Figs_Tables_ToShare. CrashEventsForRPlot: Crash Dates were determined trends in Pycnopodia occurrence (site-level presence or absence) to estimate ‘crash date’, defined as the date when the occurrence rate of Pycnopodia in a region decreased by 75% from pre-outbreak levels. Used in OutbreakTimelineFigs_ToShare.R EpidemicPhases: See manuscript methods for information on how the column ‘EpidemicPhases’ was created. “Start-End” specifies whether that date was the start or the end of that epidemic phase for that region. Used in OutbreakTimelineFigs_ToShare.R Incidence_2012-2019: Columns G-J were calculated by fitting a logistic regression model to the occurrence of Pycnopodia over time for each region. We fit a logistic regression model to the occurrence of Pycnopodia from 1/1/2012 to 12/31/2019 to model the shape of the population decline for each region (Fig. 1a). From these models, we 1) estimated regional Pycnopodia occurrence rates on 1/1/2012 and 12/31/2019, 2) calculated the predicted occurrence value corresponding to a 75% decline in starting versus ending occurrence in each region, and 3) solved the inverse logistic equations for the date at which this occurrence value was predicted. All other columns are identifying information derived from MasterPycno_ToShare. Used in OutbreakTimelineFigs_ToShare.R MasterPycno_021821_SpatialJoin: Used to make Fig 5 for the remnant population analysis....

Threats Associated with the Decline of Monarch ButterflyData are population size estimates for monarch butterflies overwintering in Mexico as well as 76 potential stressors and 3 correlates. These stressors include disease, pesticide, herbicide, temperature, precipitation, and habitat loss measured for Mexican overwintering area and Southern, North Central, and Northeastern breeding areas. Data were collected to understand the broad array of potential stressors affecting monarch butterfly population dynamics.FullThreatsData.csv

Population genetic structure can aide in developing conservation and management strategies by characterizing populations on local and regional scales. The Elegant Tern (Thalasseus elegans) has a restricted breeding range, with a majority of its nesting population historically found on Isla Rasa in the Gulf of California, Mexico. Northward expansion to southern California was noted in 1959 however, in recent years low marine productivity and warm oceanographic anomalies, such as El Nino events, have caused increased northward expansion of Elegant Tern breeding colonies into southern California, USA (San Diego Bay National Wildlife Refuge, Bolsa Chica Ecological Reserve, and Port of Los Angeles). We theorize there will be high gene flow between Gulf of California and southern California Elegant Tern breeding colonies due to northward movements of birds over the past half century. Restriction-site associated DNA sequencing (RADseq) was used to analyze 5,510 single nucleotide polymorphisms from 69 Elegant Terns sampled across four known breeding sites: 30 individuals from Isla Rasa (Mexico), 17 individuals from San Diego (USA), 11 individuals from Bolsa Chica Ecological Reserve (USA), and 11 individuals from the Port of Los Angeles (USA). Our analyses revealed little population structure, with non-significant genetic differentiation (FST) among sites. We also found no geographic association of individuals in a principal components analysis, and individual-based clustering failed to resolve any groups. Discriminant analysis of principal components suggested subtle clustering of individuals by breeding site however, based on randomization analysis, the data indicate that this outcome may be a statistical artifact. These results suggest a strong degree of connectivity (gene flow) among the Gulf of California and southern California nesting colonies. Our findings indicate that Elegant Tern breeding colonies are highly fluid and move readily among sites.

The Earth′s climate is warming, especially in the mid- and high latitudes of the Northern Hemisphere. The northern elephant seal (Mirounga angustirostris) breeds and haul-outs on islands and the mainland of Baja California, Mexico, and California, U.S.A. At the beginning of the 21st century, numbers of elephant seals in California are increasing, but the status of Baja California populations is unknown, and some data suggest they may be decreasing. We hypothesize that the elephant seal population of Baja California is experiencing a decline because the animals are not migrating as far south due to warming sea and air temperatures. Here we assessed population trends of the Baja California population, and climate change in the region. The numbers of northern elephant seals in Baja California colonies have been decreasing since the 1990s, and both the surface waters off Baja California and the local air temperatures have warmed during the last three decades. We propose that declining population sizes may be attributable to decreased migration towards the southern portions of the range in response to the observed temperature increases. Further research is needed to confirm our hypothesis; however, if true, it would imply that elephant seal colonies of Baja California and California are not demographically isolated which would pose challenges to environmental and management policies between Mexico and the United States.

Oyster collection and conditioning In December 2017 and January 2018, subtidal adult C. virginica oysters were collected from two estuaries in Louisiana, USA; Calcasieu Lake (CL; 29° 50′ 58′′ N, 93° 17′ 1′′ W) and Vermilion Bay (VB; 29° 34′ 47′′ N, 92° 2′ 4′′ W). Additionally, in August 2018 oysters were collected from two estuaries in Texas, USA; Packery Channel (PC; 27° 37′ 38′′ N, 97° 13′ 59′′ W) and Aransas Bay (AB; 28° 7′ 38′′ N, 96° 59′ 8′′ W). In August 2018, all four broodstock populations were naturally induced to spawn at the Auburn University Shellfish Laboratory (AUSL) in Dauphin Island, Alabama, as described in Marshall et al. (2021). Oyster spat were maintained in upwelling nursery systems until ~6mm in shell height, and subsequently deployed in bags at an AUSL-permitted grow-out site at Bayou Sullivan, Alabama (30° 21′ 52′′ N, 88° 12′ 57′′ W) before being moved in March 2019 to the Grand Bay Oyster Park (GBOP), Alabama (30˚ 22′ 15′′ N, 88˚ 19’ 0” W) for further growth (se...

Climate change and the northern elephant seal (Mirounga angustirostris) population in Baja California, Mexico - Table 2

Taxonomy, genetics and biogeography each make key contributions to biological conservation. However, integrating these disciplines to obtain a coherent account of the status of a taxon of concern is not always straightforward. This is the case for the cross-border endemic plant Physaria thamnophila (Brassicaceae). This US federally-listed endangered species is restricted to a set of unique geological sites just north of the Rio Grande (Rio Bravo del Norte) river in south Texas, USA. A single highly-disjunct occurrence of this species is found on a geologically and ecologically distinct site 260 km to the south, in Tamaulipas, Mexico. In this work, we quantify the genetic differentiation between the U.S. and Mexican populations using four microsatellite markers and sequences from three nuclear genes. In both sets of data, we find a high level of genetic divergence consistent with geographic isolation on a time scale of 1–2.5 million years. Further, we provide a hypothesis for the geological basis of this geographic isolation. Integrating our data with ecological, taxonomic and conservation considerations, we propose the sub-specific designation of Physaria thamnophila subsp. loretensis for the Mexican population. The evolutionary and conservation implications of this designation are presented. Methods Plant collections and DNA sampling.—All Physaria species were formerly included in the genus Lesquerella (Al-Shebaz & O’Kane 2002). Tissues were obtained from 1) laboratory-germinated seedlings, 2) herbaria specimens as listed in Appendix 1. Additional tissue collections were made from P. thamnophila populations under permit and consultation with the US Fish and Wildlife Service. We sampled all known populations of P. thamnophila in which plants were present at the time of sampling. Four populations were in Zapata County, Texas, ten in Starr County, Texas, and one in Tamaulipast, Mexico. Approximately 0.5 cm2 of tissue was used for each DNA isolation. DNAs were isolated from both fresh and dried tissue by a simple micro-scale preparation described previously (Pepper & Norwood, 2001). Microsatellite marker analyses.—Genomic DNAs from a single individual from the P. thamnophila SMR population (Starr County, Texas, U.S.A.) were used for microsatellite discovery. DNA fragments containing microsatellite (CT, CT and GG) repeats were captured using a biotinylated-oligonucleotide method described previously (Terry et al. 2006). All primers were designed to have a 45-60% GC content and a salt-adjusted (50 mM NaCl) melting temperature of 63–64°C. Amplifications were performed with Phusion Hi-Fi polymerase (New England Biolabs) using ±10 ng genomic DNA as a template. An annealing temperature of 58°C was employed for all reactions. PCR buffer and cycling conditions followed the manufacturer’s recommendations (New England Biolabs). Four microsatellite markers (Appendix 2) were amplified using fluorescently labeled primers (6-HEX and 6-FAM). Multiplexed (HEX + FAM) fragment analysis was performed using the ABI 3130 capillary DNA sequencer as described (Tarin et al. 2014). Fragment sizes were determined using GeneScan ver. 3.1 software (Applied Biosystems Inc.). Microsatellite genotyping was performed using Genotyper ver. 2.5 software (Applied Biosystems Inc.). GeneAlEx ver. 6.5 (Peakall & Smouse 2012).

The Western Hercules beetle (Dynastes grantii) is endemic to the highland forest habitats of southwestern USA and northern Mexico. The habitats harbor many endemic species, but are being threatened by rapid climate change and urban development. In this study, the genetic structure of D. grantii populations from southwestern USA was investigated. Specifically, genomic data from double-digest RADseq (ddRADseq) libraries were utilized to test whether geographically distant populations from the Mogollon Rim (Arizona [N = 12 individuals] and New Mexico [N = 10 individuals]) are genetically structured. The study also estimated the effective population size of the Mogollon Rim populations based on genetic diversity. The results indicated that the two geographic populations from the Mogollon Rim were not genetically structured. A population size reduction was detected since the end of the last glacial period, which coincided with a reduction of forest habitat in the study area. The results implied that the connectivity and the size of highland forest habitats in the Mogollon Rim could have been the major factors shaping the population genetic structure and demographic history of D. grantii. The Western Hercules beetle could be a useful flagship species for local natural history education and to promote the conservation of highland forest habitats.

These satellite tag data were collected on three species of Mobulid Ray (Mobula mobular, Mobula thurstoni, Mobula munkiana) in the southern Gulf of California between 2004 and 2014 to describe their movement patterns and habitat use. Wildlife Computers PAT tags (Mk10, MiniPAT, PAT4) were deployed. Data collected include: 1) date, time and location of PAT tag deployment; 2) date, time, and location of PAT tag pop-off; 3) light geolocation of PAT tag while at liberty; and 4) depth and temperature time series and histograms from PAT tags. Data provided in CSV and proprietary Wildlife Computers formats.

Aims: We investigate native and introduced populations of Solanum rostratum, an annual, self-compatible plant that has been introduced around the globe. This study is the first to compare the genetic diversity of Solanum rostratum between native and introduced populations. We aim to (1) determine the level of genetic diversity across the studied regions; (2) explore the likely origins of invasive populations in China; and (3) investigate whether there is the evidence of multiple introductions into China. Methods: We genotyped 329 individuals at 10 microsatellite loci to determine the levels of genetic diversity and to investigate population structure of native and introduced populations of S. rostratum. We studied five populations in each of three regions across two continents: Mexico, the U.S.A. and China. Important Findings: We found the highest genetic diversity among Mexican populations of S. rostratum. Genetic diversity was significantly lower in Chinese and U.S.A. populations, but...