Broadening the migratory portfolio of altitudinal migrants.
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ABSTRACT:
SUBMITTER: Denryter K
PROVIDER: S-EPMC8459274 | biostudies-literature | 2021 Aug
REPOSITORIES: biostudies-literature
Publications
Broadening the migratory portfolio of altitudinal migrants.
Denryter Kristin K Stephenson Thomas R TR Monteith Kevin L KL
Ecology 20210430 8
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Project description:BackgroundMigrating birds experience weather conditions that change with time, which affect their decision to stop or resume migration. Soaring migrants are especially sensitive to changing weather conditions because they rely on the availability of environmental updrafts to subsidize flight. The timescale that local weather conditions change over is on the order of hours, while stopovers are studied at the daily scale, creating a temporal mismatch.MethodsWe used GPS satellite tracking data from four migratory Turkey Vulture (Cathartes aura) populations, paired with local weather data, to determine if the decision to stopover by migrating Turkey Vultures was in response to changing local weather conditions. We analyzed 174 migrations of 34 individuals from 2006 to 2019 and identified 589 stopovers based on variance of first passage times. We also investigated if the extent of movement activity correlated with average weather conditions experienced during a stopover, and report general patterns of stopover use by Turkey Vultures between seasons and across populations.ResultsStopover duration ranged from 2 h to more than 11 days, with 51 % of stopovers lasting < 24 h. Turkey Vultures began stopovers immediately in response to changes in weather variables that did not favor thermal soaring (e.g., increasing precipitation fraction and decreasing thermal updraft velocity) and their departure from stopovers was associated with improvements in weather that favored thermal development. During stopovers, proportion of activity was negatively associated with precipitation but was positively associated with temperature and thermal updraft velocity.ConclusionsThe rapid response of migrating Turkey Vultures to changing weather conditions indicates weather-avoidance is one of the major functions of their stopover use. During stopovers, however, the positive relationship between proportion of movement activity and conditions that promote thermal development suggests not all stopovers are used for weather-avoidance. Our results show that birds are capable of responding rapidly to their environment; therefore, for studies interested in external drivers of weather-related stopovers, it is essential that stopovers be identified at fine temporal scales.
| S-EPMC8272267 | biostudies-literature
Project description:Migration has evolved among many animal taxa and migratory species are found across all major lineages. Insects are the most abundant and diverse terrestrial migrants, with trillions of animals migrating annually. Partial migration, where populations consist of resident and migratory individuals, is ubiquitous among many taxa. However, the underlying mechanisms are relatively poorly understood and may be driven by physiological, behavioural or genetic variation within populations. We investigated the differences in migratory tendency between migratory and resident phenotypes of the hoverfly, Episyrphus balteatus, using tethered flight mills. Further, to test whether migratory flight behaviour is heritable and to disentangle the effects of environment during development, we compared the flight behaviour of laboratory-reared offspring of migrating, overwintering and summer animals. Offspring of migrants initiated more flights than those of resident individuals. Interestingly, there were no differences among wild-caught phenotypes with regard to number of flights or total flight duration. Low activity in field-collected migrants might be explained by an energy-conserving state that migrants enter into when under laboratory conditions, or a lack of suitable environmental cues for triggering migration. Our results strongly suggest that flight behaviour is heritable and that genetic factors influence migratory tendency in E. balteatus These findings support the growing evidence that genetic factors play a role in partial migration and warrant careful further investigation.
| S-EPMC6030531 | biostudies-literature
Project description:ObjectiveTo evaluate the factors associated with food insecurity (FI) among Venezuelan migrants residing in Peru. Secondarily, to evaluate the psychometric properties of the Food Insecurity Experience Scale (FIES).DesignA cross-sectional study based on secondary data analysis of the 2022 Venezuelan Population Residing in Peru Survey (ENPOVE-2022, from the Spanish acronym) was conducted. FI was measured with the FIES, whose properties were tested using the Rasch model. Multinomial logistic regression was performed to estimate relative prevalence ratios with their corresponding 95 % confidence intervals.SettingThis survey was conducted in February and March 2022 in the eight cities most populated by Venezuelan migrants and refugees in Peru.ParticipantsVenezuelan migrants and refugees over the age of 18 years living in Peru.ResultsA total of 7727 participants were included. Rasch reliability was adequate (0·73). The prevalence of mild, moderate and severe FI was 36·71 %, 31·14 % and 10·48 %, respectively. Being aged 25-34 and 35-44 years, unemployed, uninsured, having no formal education or secondary, illegal status, living in a dwelling with 2-4 and more than 4 people, presenting one or more than one chronic disease, residing in Peru for 0-6 months and perceived discrimination were associated with a higher probability of moderate FI. Furthermore, having secondary education, being unemployed, uninsured, never married, illegal, residing in Tumbes, presenting one or more than one chronic disease and perceived discrimination were significantly associated with severe FI.ConclusionFour out of ten Venezuelan migrants residing in Peru presented moderate to severe FI. The FIES showed adequate psychometric properties. Differences in the socio-demographic, health and migratory factors associated with FI levels were found. Inter-sectoral and multi-sectoral interventions are needed and should be focused on addressing the determinants of FI.
| S-EPMC10755391 | biostudies-literature
Project description:BackgroundIn 2015 the increased migratory pressure in Europe posed additional challenges for healthcare providers. The aim of this study was to inform the development of a "Resource Package" to support European Union (EU) member states in improving access to healthcare for refugees, asylum seekers and other migrants.MethodsA mixed method approach was adopted: i) interviews and focus groups were carried out to gather up-to-date information on the challenges the different healthcare providers were facing related to the refugee crisis; ii) to complement the results of the FGs, a literature review was conducted to collect available evidence on barriers and solutions related to access to healthcare for refugees and migrants.ResultsThe different actors providing healthcare for refugees and migrants faced challenges related to the phases of the migration trajectory: arrival, transit and destination. These challenges impacted on the accessibility of healthcare services due to legislative, financial and administrative barriers; lack of interpretation and cultural mediation services; lack of reliable information on the illness and health history of migrant patients; lack of knowledge of entitlements and available services; lack of organisation and coordination between services. These barriers proved particularly problematic for access to specific services: mental health, sexual and reproductive care, child & adolescent care and victim of violence care.ConclusionsThe findings of this study show that solutions that are aimed only at responding to emergencies often lead to fragmented and chaotic interventions, devolving attention from the need to develop structural changes in the EU health systems.
| S-EPMC6651950 | biostudies-literature
Project description:As environmental conditions fluctuate across years, seasonal migrants must determine where and when to move without comprehensive knowledge of conditions beyond their current location. Animals can address this challenge by following cues in their local environment to vary behaviour in response to current conditions, or by moving based on learned or inherited experience of past conditions resulting in fixed behaviour across years. It is often claimed that long-distance migrants are more fixed in their migratory behaviour because as distance between breeding and wintering areas increases, reliability of cues to predict distant and future conditions decreases. While supported by some population-level studies, the influence of migration distance on behavioural variation is seldom examined on an individual level. Lesser black-backed gulls Larus fuscus are generalist seabirds that use a diversity of migration strategies. Using high-resolution multi-year GPS tracking data from 82 individuals from eight colonies in Western Europe, we quantified inter- and intra-individual variation in non-breeding distributions, winter site fidelity, migration routes and timing of migration, with the objectives of determining how much variation lesser black-backed gulls have in their migratory behaviour and examining whether variation changes with migration distance. We found that intra-individual variation was significantly lower than variation between individuals for non-breeding distributions, winter site fidelity, migration routes and timing of migration, resulting in consistent individual strategies for all behaviours examined. Yet, intra-individual variation ranged widely among individuals (e.g. winter site overlap: 0-0.91 out of 1; migration timing: 0-192 days), and importantly, individual differences in variation were not related to migration distance. The apparent preference for maintaining a consistent strategy, present in even the shortest distance migrants, suggests that familiarity may be more advantageous than exactly tracking current environmental conditions. Yet, variation in behaviour across years was observed in many individuals and could be substantial. This suggests that individuals, irrespective of migration distance, have the capacity to adjust to current conditions within the broad confines of their individual strategies, and occasionally, even change their strategy.
| S-EPMC8247866 | biostudies-literature
Project description:IntroductionMigration creates new health vulnerabilities and exacerbates pre-existing medical conditions. Migrants often face legal, system-related, administrative, language and financial barriers to healthcare, but little is known about factors that specifically influence migrants' access to medicines and vaccines. This scoping review aims to map existing evidence on access to essential medicines and vaccines among asylum seekers, refugees and undocumented migrants who aim to reach Europe. We will consolidate existing information and analyse the barriers that limit access at the different stages of the migratory phases, as well as policies and practices undertaken to address them.MethodsWe follow the Arksey and O'Malley framework for knowledge synthesis of research, as updated by Levac et al. For reporting the results of our search and to synthetise evidence, we will adhere to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extended reporting guideline for scoping reviews. This scoping review consists of five iterative stages. Bibliographic databases (PubMed, CINAHL, Cochrane Database of Systematic Reviews and Scopus) and grey literature databases (Open Grey, Grey Literature Report and Google Scholar, Web of Science Conference Proceedings, non-governmental organisations and United Nations agency websites) will be searched for relevant studies.Dissemination and ethicsThis review will be disseminated through a peer-reviewed article in a scientific open-access journal and conference presentations. Furthermore, findings will be shared at workshops of research and operational stakeholders for facilitating translation into research and operational practices. Since it consists of reviewing and collecting data from publicly available materials, this scoping review does not require ethics approval.
| S-EPMC9743384 | biostudies-literature
Project description:Mammalian primordial germ cells (PGCs) migrate asynchronously through the embryonic hindgut and dorsal mesentery to reach the gonads. To characterize transcriptional heterogeneity of migrating PGCs and their niches, we performed single-cell RNA sequencing of 13,262 mouse PGCs and 7,868 surrounding somatic cells during migration (E9.5, E10.5, E11.5) and in anterior versus posterior locations to enrich for leading and lagging migrants. Analysis of PGCs by position revealed dynamic gene expression changes between faster or earlier migrants in the anterior and slower or later migrants in the posterior at E9.5. At E10.5, we found that anterior PGCs upregulate Nodal transcriptional targets including Lefty1/2 and validated this LEFTY1/2 upregulation via whole-mount immunofluorescence staining. This positional and temporal atlas of mouse PGCs supports the idea that niche interactions along the migratory route elicit changes in proliferation, actin dynamics, pluripotency and epigenetic reprogramming.
2024-10-08 | GSE274603 | GEO
Project description:IntroductionAccess to essential medicines is a critical element of health systems and an important measure of their performance. Migrants may face barriers in accessing healthcare, including essential medicines, throughout the migration cycle, which includes the stages of departure from home or residence countries, transit through non-European or European countries, reception and settlement in a country in Europe and deportation. We aim to provide an overview of research and grey literature concerning access to essential medicines for asylum seekers, refugees and undocumented migrants in or heading to Europe (European Union, European Economic Area, Switzerland and the UK).MethodsTo delineate and conceptualise access to medicines, we considered the definition of the Lancet Commission on Essential Medicines and the Pharmaceutical Management framework. These frameworks were combined to guide several critical steps in our review, including defining the search terms, data extraction, data analyses and reporting. Relevant studies and reports were identified through searches in bibliographic and grey literature databases.ResultsOut of 5760 studies and 66 grey literature reports, 108 met the inclusion criteria, with 72 focusing on medicine access. Overall, medicine use and medicine expenditure were found to be lower in migrant populations compared with the host population in many European countries. Although many studies focused on the use of infectious disease and psychotropic medicines, the most frequently used medicines by migrants were analgesics, hypertension and diabetes medicines. Determinants of medicine access were legal restrictions, language and transit times, which all contributed to interruption of and inequities in access to medicines among this population. This scoping review also indicated significant gaps in the literature regarding the evidence on access to medicine at different stages of the migration cycle, specifically in departure, transit and deportation stages.ConclusionOverall, our findings highlighted significant unmet medicine needs among migrants in or on the way to Europe and access disparities attributable to various interconnected barriers. Urgent access is needed to address such inequities, particularly legal barriers, including registration of certain medicines required for treatment. Future research should prioritise investigating medicine access during departure, transit and deportation stages. Policy discussions around migrants' access to medicines should be centred on framing healthcare as a fundamental right.
| S-EPMC11481121 | biostudies-literature
Project description:COVID-19 has taught us that a pandemic can significantly increase biometric risk and at the same time trigger crashes of the stock market. Taking these potential co-movements of financial and non-financial risks into account, we study the portfolio problem of an agent who is aware that a future pandemic can affect her health and personal finances. The corresponding stochastic dynamic optimization problem is complex: It is characterized by a system of Hamilton-Jacobi-Bellman equations which are coupled with optimality conditions that are only given implicitly. We prove that the agent's value function and optimal policies are determined by the unique global solution to a system of non-linear ordinary differential equations. We show that the optimal portfolio strategy is significantly affected by the mere threat of a potential pandemic.
| S-EPMC9131511 | biostudies-literature
Project description:Over decades it has been unclear how individual migratory songbirds cross large ecological barriers such as seas or deserts. By deploying light-level geolocators on four songbird species weighing only about 12 g, we found that these otherwise mainly nocturnal migrants seem to regularly extend their nocturnal flights into the day when crossing the Sahara Desert and the Mediterranean Sea. The proportion of the proposed diurnally flying birds gradually declined over the day with similar landing patterns in autumn and spring. The prolonged flights were slightly more frequent in spring than in autumn, suggesting tighter migratory schedules when returning to breeding sites. Often we found several patterns for barrier crossing for the same individual in autumn compared to the spring journey. As only a small proportion of the birds flew strictly during the night and even some individuals might have flown non-stop, we suggest that prolonged endurance flights are not an exception even in small migratory species. We emphasise an individual's ability to perform both diurnal and nocturnal migration when facing the challenge of crossing a large ecological barrier to successfully complete a migratory journey.
| S-EPMC4753512 | biostudies-literature