Seasonal Migration Research Articles

Exploring Hidden Costs of Seasonal Migration in Agriculture within Roma Communities of Origin: Evidence from Romania

The article is focused on researching the hidden effects of seasonal migration in agriculture on Roma communities in Romania. The theoretical framework considers the specific nature of seasonal migration in agriculture and includes elements relevant to understanding the seasonal migration patterns of the Roma population from Romania. The research is based on a qualitative methodological design and over 120 interviews in four communities with Roma individuals and key actors at the community level (e.g., local authorities, teachers, priests, and social workers). The interviews are thematically analyzed, and the hidden costs of seasonal migration are discussed at three levels of analysis: individual, familial, and community. First and foremost, the analysis emphasizes that migration is the most significant factor of social change in the studied Roma communities, and its effects are multifaceted. The analysis reveals significant negative costs of migration in terms of health, education, employability, family, and community life. In the medium and long term, these effects decrease the positive aspects linked to the material gains from migration, making these Roma communities more vulnerable and dependent.

Birds of a feather flock together: a dataset for Clock and Adcyap1 genes from migration genetics studies

Birds in seasonal habitats rely on intricate strategies for optimal timing of migrations. This is governed by environmental cues, including photoperiod. Genetic factors affecting intrinsic timekeeping mechanisms, such as circadian clock genes, have been explored, yielding inconsistent findings with potential lineage-dependency. To clarify this evidence, a systematic review and phylogenetic reanalysis was done. This descriptor outlines the methodology for sourcing, screening, and processing relevant literature and data. PRISMA guidelines were followed, ultimately including 66 studies, with 34 focusing on candidate genes at the genotype-phenotype interface. Studies were clustered using bibliographic coupling and citation network analysis, alongside scientometric analyses by publication year and location. Data was retrieved for allele data from databases, article supplements, and direct author communications. The dataset, version 1.0.2, encompasses data from 52 species, with 46 species for the Clock gene and 43 for the Adcyap1 gene. This dataset, featuring data from over 8000 birds, constitutes the most extensive cross-species collection for these candidate genes, used in studies investigating gene polymorphisms and seasonal bird migration.

The pace of mitochondrial molecular evolution varies with seasonal migration distance.

Animals that engage in long-distance seasonal migration experience strong selective pressures on their metabolic performance and life history, with potential consequences for molecular evolution. Species with slow life histories typically show lower rates of synonymous substitution (dS) than "fast" species. Previous research suggests long-distance seasonal migrants have a slower life history strategy than short-distance migrants, raising the possibility that rates of molecular evolution may covary with migration distance. Additionally, long-distance migrants may face strong selection on metabolically-important mitochondrial genes due to their long-distance flights. Using over 1,000 mitochondrial genomes, we assessed the relationship between migration distance and mitochondrial molecular evolution in 39 boreal-breeding migratory bird species. We show that migration distance correlates negatively with dS, suggesting that the slow life history associated with long-distance migration is reflected in rates of molecular evolution. Mitochondrial genes in every study species exhibited evidence of purifying selection, but the strength of selection was greater in short-distance migrants, contrary to our predictions. This result may indicate effects of selection for cold tolerance on mitochondrial evolution among species overwintering at high latitudes. Our study demonstrates that the pervasive correlation between life history and molecular evolutionary rates exists in the context of differential adaptations to seasonality.

The (big) role of family constellations in return migration and transnationalism

PurposeThe Albanian migration has always reflected a family character, be that before 1945 when Albania was not yet completely isolated, as well as after 1990 when borders were reopened. This feature characterized all types of movement, internal or international, permanent or seasonal migration, return migration or transnational movements and remigration. The purpose of this study is to investigate the role of the family as a very important factor in making decisions regarding migration and answering questions from why to how to migrate, from when to where, whom to ask for help or how to invest remittances.Design/methodology/approachBased on the case study of a rural area in Northern Albania, the Administrative Unit of Dajç, this paper explores in detail the roles of family and kinship on decisions regarding return migration, the re-adjustment process, remigration or transnational life.FindingsBy exploring the role of the family context in remigration and vice-versa, the paper reflects that the family biography – including the lifestyle, plans for the future or expectations – has changed due to previous migration experiences or challenges and difficulties when returning to the home country.Originality/valueIt demonstrates how individual decisions to migrate or to “return home” are negotiated and supported within families making transnational life a family project. The paper adopts a new approach in the Albanian Migration Studies, which may be implied on broader areas for further research in the future.

Kabalis / Kabalia Yüksek Yayla Yerleşimlerinde Zeus ve Şimşek Demeti Kabartmaları

The worship of Zeus, the head of the gods of Olympus, is more widespread in rural areas than in urban centers in the Kabalis / Kabalia region. Zeus, who is generally seen in cities for the prosperity and well-being of the city or for amity in treaties, has a different presence in rural areas than the established cult in the cities. Zeus, who is mostly associated with the sky and celestial phenomena, also manifests himself in rural life in agriculture and animal husbandry. In this context, the bust of Zeus and the reliefs, altars and architectural blocks bearing winged or wingless thunderbolt, the attribute of Zeus and recorded in ancient literature, were analyzed on the basis of rural life and especially seasonal migration. In addition to these finds, two altars, one with an inscription, registered in the inventory of the Burdur Archaeological Museum, were also included in the research, and, in relation to rural life and transhumance activities the characteristics related to this deity were investigated. This depiction, which is sometimes seen as a winged thunderbolt and sometimes as a thunderbolt carried by an eagle on the coins of the cities of the Kabalis / Kabalia Region during the Hellenistic Period, appears on rock reliefs, architectural blocks, and altars in the high plateaus, permanent or periodic rural settlements during the Roman Imperial Period. Through the identification of the finds in the region, including those with similar reliefs, a preliminary impression of the epithets with which this deity may have been worshipped has been attempted.

Историко-экономический экскурс развития межрегиональных миграционных потоков и видов занятости (на примере Царицына – Сталинграда и прилегающих территорий)

Introduction. The purpose of the study is determined by the significance of the formation of labor resources for territorial development. The choice of the object is determined by the presence of historical experience of the growth of interregional migration flows in the territories under consideration. Methods and materials. Statistical collections, materials from general and agricultural censuses, and one-time surveys of the late 19th and early 20th centuries were used. Historical-evolutionary approaches and statistical methods of analysis are applied. Analysis. The migration flows are determined, and their statistical features are identified: 1) seasonal migration before the construction of the railway in 1862; 2) changes in seasonal migration after 1862; 3) formation of qualified and unskilled immigration flows with high settlement when developing factory activity (1897); 4) migration of the period of the First World War and the Civil War in connection with military operations; 5) a gradual reduction in spontaneity and an increase in the regularity of migration processes in the 20–30s of the 20th century. Results. The formation of interregional migration flows and types of employment is determined by the prevailing technological order, existing social institutions, opportunities to have a source of income, similarity of lifestyle, and the insignificance of the shoulder of territorial displacement. Recommendations are formulated based on the use of historical experience to predict migration flows and ensure their specific orientation, for example, for the currently developing digital economy, including the gig economy. Authors’ contribution. T.B. Ivanova identified historical sources, analyzed the patterns of development, and framed the text of the article. S.M. Mironova participated in identifying patterns of historical processes and preparing the article.

Дороги в жизни калмыцкого ханства XVIII в. (на материале документов Национального архива Республики Калмыкия)

Introduction. The object of the analysis is the ways in which the Kalmyk Khanate of the 18th century used communication routes and movements along these paths for a specific purpose. Methods and materials. The official correspondence of Kalmyk khans and owners with representatives of different government levels of the Russian state of the 18th century from the funds of the National Archives of the Republic of Kalmykia is considered, data on the movements of representatives of the Kalmyk Khanate is revealed, and a typology of these movements is proposed. Analysis. It is shown that ways differ in place, time, and purpose of movement. In the life of the Kalmyks, internal and external ways stood out. The internal ones are seasonal migrations within the khanate in order to change pastures for livestock. The documents report on the places of nomads, folk traditions, holidays, and various difficulties. External ways connected the Kalmyks with the world outside the khanate and were divided into postal (communication between different subjects), official (delivery of salaries, trips on judicial and other matters), diplomatic (visits to the court, trips to other states to conclude and maintain peace), military (military campaigns, border protection), trade (trips to Russian and other cities for the purchase and sale of livestock and various goods), and religious (pilgrimage to Tibet, trips for baptism to Stavropol-on-the-Volga). Results. The conclusion is made about the great importance of both internal ways, which determined the mode of life of the nomadic people, and external ones, thanks to which interaction with the Russian state and other countries was carried out. Sources of Kalmyk and Russian origin reveal facts from different points of view and show the actions of both sides as the realization of their complex, multifaceted interaction. Authors’ contribution. D.A. Suseeva proposed the classification principles, identified the main way types, and analyzed the letters of the Kalmyk khans and owners. O.A. Gorban supplemented the classification with individual species and analyzed V.N. Tatishchev’s letters and other documents of the Kalmyk Commission.

Tayeb Salih's Season of Migration to the North: Investigating Stereotypes and the Dehumanizing Effects of Colonialism

Long before colonialism emerged as an imperial project, cultural stereotypes and myths have fed the Western discourse about the Orient. Even during the medieval ages and Renaissance period, the discourse about Muslims and Islam was deeply informed of the distorted images, fabricated views, and overgeneralizations rooted in racial and religious prejudices. These myths were popularized through European art and literature to construct a particular narrative later used to legitimize the imperial designs and economic control of the native people. The research views this dehumanization of people and the vicious cycle of psychological trauma as a direct result of colonial enterprises by imperial forces. Using anti-colonial theories and postcolonialism as a framework of the study and building on the works of anticolonial theorists like Fanon, Memmi, and Césaire, the research seeks to investigate how these dehumanized images form the core of imperial designs and how colonialism dehumanizes people, distorts perspectives, engenders alienation and perpetuates a cycle of psychological violence across cultures and regions.

“Our Poverty has No Shame; the Stomach has No Shame, so We Migrate Seasonally”: Women Sugarcane Cutters from Maharashtra, India

During the season of sugarcane cutting, men and women seasonally migrate toward the sugar belt. Drought conditions in their native districts are always highlighted as the reasons for seasonal migration. However, existing literature on sugarcane cutters emphasizes that mostly poor, lower caste, landless, small landholders, and resourceless people migrate to the sugar belt. Even pregnant or lactating mothers are not an exception for seasonal migration and the work of sugarcane cutting. In Maharashtra, issues like poor work conditions, labor rights, financial exploitation, hysterectomy among women, citizenship status, education, and health of sugarcane cutters are already in the discussion forums. After migration, these workers live without housing, sanitation facilities, and drinking water. For women, there is no social, economic, labor, and personal security. Workers have to bathe, defecate openly, and drink untreated water. Specifically, women have special health needs, and there should not be a compromise while accessing essential health services. Considering the background information, this article considers questions like why women migrate in adversity and do women work for the Sugar Belt without facing any hardship? People at large relate the phenomenon of migration to human development or economic development. Similarly, it is possible to study internal migration or seasonal migration. Nevertheless, the analysis argues that seasonal migration of the poor, unskilled, illiterate, lower caste, landless, resourceless, and vulnerable cannot be connected to human development. Instead, we can relate it to survival at large. Significantly, the ignorance of the state towards these workers and their needs can be seen from the perspective of social exclusion.

Seasonal morphological evolution and migration of granule ripples in the Sanlongsha Dune Field, northern Kumtagh Sand Sea, China

Granule ripples are aeolian landforms that are armored against erosion by coarse grains at their crest. Their bimodal grain-size distributions and large dimensions distinguish them from normal wind ripples. The morphodynamics of granule ripples have attracted considerable attention because they provide a good example of coarse-grained aeolian bedforms. Previous studies have mainly focused on the morphological characteristics and formation process of granule ripples, but their evolution has been less studied. Using unpiloted aerial vehicle photogrammetry and real-time kinematic positioning, we conducted five field observations in the Sanlongsha Dune Field of northern China's Kumtagh Sand Sea. We analyzed the seasonal morphological evolution and migration of granule ripples, and the corresponding wind regimes. The morphometric parameters and migration rate showed distinctly different changes in different periods. The lowest height, the fastest migration, and most of the disintegration of granule ripples occurred in the season with the strongest wind. Although the proportions of wind speeds that exceeded the impact and fluid threshold velocities of coarse grains were low, these wind events significantly influenced the morphodynamics of granule ripples. Our findings and theoretical analysis demonstrate that the evolution of granule ripples is closely related to bimodal and unimodal transport events. To enhance our understanding of the morphodynamics of granule ripples, we must focus future research on the reptation and saltation of coarse grains.

Тюркоязычное население степного пограничья Великого княжества Литовского и Крымского ханства в ХV – первой половине ХVІ вв.

The ethnic and demographic situation on the borderland of the Grand Duchy of Lithuania and the Crimean Khanates is analysed on the basis of narratives (Michalon Lituanus, Marcin Broniowski, Marcin Bielski, Bartosz Paprocki) and documentary sources (publications “Lithuanian Metrics”, “Archive of South Western Russia”, documents of the Russian State Archive of Ancient Acts, Central State Historical Archive of Ukraine).
 The boundaries laid by the local prince of Kiev Simeon Olelkovich in the 15th century were significant for a later time as a precedent for ideas about the boundary between the Black Sea Tatars and Ukrainian Cossacks. The Zaporozhian Host at the early 18th century referred it as “Vytautas borders”. However, this “boundary” was conditional. The steppe space between the rivers Southern Bug and Dnieper was occupied by the Ukrainian Cossacks (later the Zaporozhians) in the summer, and by the “Perekop Tatars” in the winter. The seasonal migrations, set by the conditions of the first half of the 16th century, persisted until the middle of the 17th century.
 The notion “Tatars” is a conventional designation for the Turkic-speaking population in the Black Sea steppe before the migration of the Noghais to this region in the second half of the 16th to early 17th centuries. “Perekop Tatars” were not nomads, but a semi-sedentary population. Economic occupations and the degree of settlement of this population differed according to gender, age and social position. Women, children, clients and slaves lived in stationary settlements, were engaged in agriculture and horticulture. Full-fledged men led an mobile lifestyle, were engaged in stockbreeding, hunting and war. The economy was based on sheep and horse breeding.
 Particular attention is paid to the male groups of the “Perekop Tatars”, which had a changeable and often multiethnic composition, combined shepherding and war, and for a long time were without a family and permanent place of residence. Some demographic data (cited by Gilles Veinstein) indicate a significant excess of the number of men relative to women. These male groups in the sources of that time are designated as “Kazak” and “Çoban”.

Social and ecological drivers of illegal bird hunting in the Indawgyi wetland ecosystem in Myanmar

AbstractHunting and illegal bird killing are major concerns for avian conservation globally. Unsustainable bird hunting in wetland habitats, particularly those located along important flyways, has contributed to avifauna defaunation and species endangerment. Since wetlands are primary habitats for migratory birds and are associated with anthropogenic landscapes, a comprehensive understanding of bird harvesting, and its drivers is fundamental to reduce threats to current avifauna. In this study, we examined the distribution of illegal bird hunting and its socioecological drivers in the Indawgyi wetland ecosystem in Myanmar by integrating data from bird surveys, household surveys, and market surveys. We found that illegal bird hunting using nets, traps, and poisonous substances is prevalent in areas close to water and during the migration season. People who had negative attitudes toward avian species were more likely to engage in bird hunting, primarily because of the conflicts between bird conservation and crop production. Socioeconomic needs were not the major driving factors of bird killing. We therefore suggest sustainable management interventions promoting coexistence by integrating bird conservation and agricultural production, accompanied by increasing awareness to improve avian conservation in an internationally important wetland in Myanmar.

TRANSLATING TAYEB SALIH’S PSYCHOLOGICAL TRAUMA AS REPRESENTED IN HIS NOVEL SEASON OF MIGRATION TO THE NORTH: A SEARCH FOR BELONGINGNESS

Tayeb Salih, a prominent British author of Arabic language and origin is regarded as a pioneer who carved an identity of African-Arab literature globally. Salih acclaimed in one of his interviews in the Arabic press that he attempted to reshape the East and West relationship conceived by the world. He stated that the West romanticizes the idea of the East-West interaction merely as an emotion whereas it is an unresolved conflict that leads a trauma related to loss of identity, belongingness, and existentialism (Salih, 1929). Denys Johnson-Davies, an accredited translator, credited with making Arabic literature accessible to readers of the English language, who also translated Salih’s Season of Migration to the North (1966) regards the author and this literary piece as an intelligent work on East-West conflict produced by any Western or non-Western author. Season of Migration to the North provides a tapestry of events, multi-layered interpretations, traumatic outbreaks, struggles to identify with the world and finally succumbing to the pain. It is not a simple story of physical migration and the life of an African on the European land. It is an embodiment of an emotional, spiritual, religious, and mental search for belongingness. This present research is an attempt to capture the journey of the protagonist Mustafa Saeed and his life from his birth as a slave in the then colony of Britain, Sudan to his migration to Britain as a free individual. The rollercoaster of events that shape him and his destiny. Did he manage to break the clutches of his birth and slavery? Did he attain freedom from his belongingness to a British colony? Did he get peace to fly away from his roots is what makes this novel an extremely viable research material. The authors attempt to explore the psychological trauma and translate the author’s search for belongingness and understand the East-West relationship from his perspective.

Greylag Goose Optimization: Nature-inspired optimization algorithm

Nature-inspired metaheuristic approaches draw their core idea from biological evolution in order to create new and powerful competing algorithms. Such algorithms can be divided into evolution-based and swarm-based algorithms. This paper proposed a new nature-inspired optimizer called the Greylag Goose Optimization (GGO) algorithm. The proposed algorithm (GGO) belongs to the class of swarm-based algorithms and is inspired by the Greylag Goose. Geese are excellent flyers and during their seasonal migrations, they fly in a group and can cover thousands of kilometers in a single flight. While flying, a group of geese forms themselves as a “V” configuration. In this way, the geese in the front can minimize the air resistance of the ones in the back. This allows the geese to fly around 70% farther as a group than they could individually. The GGO algorithm is first validated by being applied to nineteen datasets retrieved from the UCI Machine Learning Repository. Each dataset contains a varied amount of characteristics, instances, and classes that are used to choose features. After that, it is put to use in the process of solving a number of engineering benchmark functions and case studies. Several case studies are solved using the proposed algorithm too, including the pressure vessel design and the tension/compression spring design. The findings demonstrate that the GGO method outperforms numerous other comparative optimization algorithms and delivers superior accuracy compared to other algorithms. The results of the statistical analysis tests, such as Wilcoxon’s rank-sum and one-way analysis of variance (ANOVA), demonstrate that the GGO algorithm achieves superior results.

The birds of Cameroon: bird survey in a forest plain of the Congo basin forest (Oveng, Cameroon) confirms the great diversity of birds linked to the vegetation of the second largest biodiversity reserve in the world as well as the distribution pattern of taxa

We carried out a bird survey in the Oveng plain in the Congo Basin Forest to investigate the avifauna as well as to explore the abundance, diversity and distribution of taxa. To obtain abundance of bird species and analyze their diversity and distribution, we used the mist net method for bird sampling for five months and performed analyzes with SAS/STAT and PAST software, respectively; moreover, to compare the diversity and dominance of the Oveng plain to other plains already explored, we proceeded to a simple comparison for a small sample, placing the values in a double-entry table and analyzing them. We captured 146 individuals belonging to 22 bird families and compared to previous surveys in this region, we recorded three new species, Campethera maculosa, Buccanodon duchaillui and Alethe diademeta; the birds caught were mainly sedentary and the rest were a mixture of intra-African, seasonal and Palearctic migrants, etc. Values ​​of the diversity indices show a great avifaunistic diversity within the Oveng site; thus, the Shannon-Wiener index (H’= 3.09) expresses the high number of the species within the Oveng avifauna while the Equitability index (J’=0.83) reveals an absence of dominance of one species and therefore an equal distribution of individuals within species. The Simpson index (λ=0.92) supports abundant species representation in Oveng’s birdlife due to the presence of year-round vegetation. The distribution pattern of taxa appeared directly linked to vegetation. Comparison of the diversity and dominance of plains avifauna supports a close relationship between the presence of vegetation and a high diversity of birds and that between an absence of vegetation and a more pronounced dominance.

Spatiotemporal Intertropical Convergence Zone dynamics during the last 3 millennia in northeastern Brazil and related impacts in modern human history

Abstract. Changes in tropical precipitation over the past millennia have usually been associated with latitudinal displacements of the Intertropical Convergence Zone (ITCZ). Recent studies provide new evidence that contraction and expansion of the tropical rain belt may also have contributed to ITCZ variability on centennial timescales. Over tropical South America few records point to a similar interpretation, which prevents a clear diagnosis of ITCZ changes in the region. In order to improve our understanding of equatorial rain belt variability, our study presents a reconstruction of precipitation for the last 3200 years from the northeastern Brazil (NEB) region, an area solely influenced by ITCZ precipitation. We analyze oxygen isotopes in speleothems that serve as a faithful proxy for the past location of the southern margin of the ITCZ. Our results, in comparison with other ITCZ proxies, indicate that the range of seasonal migration, contraction, and expansion of the ITCZ was not symmetrical around the Equator on secular and multidecadal timescales. A new NEB ITCZ pattern emerges based on the comparison between two distinct proxies that characterize the ITCZ behavior during the last 2500 years, with an ITCZ zonal pattern between NEB and the eastern Amazon. In NEB, the period related to the Medieval Climate Anomaly (MCA – 950 to 1250 CE) was characterized by an abrupt transition from wet to dry conditions. These drier conditions persisted until the onset of the period corresponding to the Little Ice Age (LIA) in 1560 CE, representing the longest dry period over the last 3200 years in NEB. The ITCZ was apparently forced by teleconnections between Atlantic and Pacific that controlled the position, intensity, and extent of the Walker cell over South America, changing the zonal ITCZ characteristics, while sea surface temperature changes in both the Pacific and Atlantic stretched or weakened the ITCZ-related rainfall meridionally over NEB. Wetter conditions started around 1500 CE in NEB. During the last 500 years, our speleothems document the occurrence of some of the strongest drought events over the last centuries, which drastically affected population and environment of NEB during the Portuguese colonial period. The historical droughts were able to affect the karst system and led to significant impacts over the entire NEB region.

The Seasonal Migrants Spatially Affect the Park Green Space Accessibility and Equity under Different Travel Modes: Evidence from Sanya, China

The influx of seasonal migrants has a significant impact on public services in destination places and may reshape the spatial accessibility and equity patterns of park green space (PGS). However, the two-step floating catchment area (2SFCA) method and its extended forms neglect discrepancies between the travel behaviors of seasonal migrants and native residents and thus fail to delineate variations in PGS accessibility and equity in areas with seasonal migrants. To avoid this issue, this study drew on the case of Sanya, a city with large numbers of Houniao, who are primarily retirees leading seasonal migration between the north and the south of China. A multi-group, multi-mode Gaussian-based 2SFCA method was also proposed to evaluate the PGS accessibility and equity before and after the Houniao influx. The method considered the changes in the COVID-19 restrictions from a refined perspective, with fine-scale residential areas being the research units and travel time requested from the web map application programming interface. The results showed that most residential areas were found to have relatively low PGS accessibility and equity levels, except for those in the south-central and southwestern urban areas of Sanya. Both the Houniao influx and lifted COVID-19 restrictions affected the spatial patterns of PGS accessibility and equity. PGS accessibility and equity were decreased by the Houniao influx, whereas walking and public transport within a few residential areas outside Houniao gathering spots improved. This study can serve as a basis for the reasonable planning of PGS and other public services in cities receiving seasonal migrants, such as Sanya.

The role of seasonal migration in spatial population synchrony.

Spatially synchronized population dynamics are common in nature, and understanding their causes is key for predicting species persistence. A main driver of synchrony between populations of the same species is shared environmental conditions, which cause populations closer together in space to be more synchronized than populations further from one another. Most theoretical and empirical understanding of this driver considers resident species. For migratory species, however, the degree of spatial autocorrelation in the environment may change across seasons and vary by their geographic location along the migratory route or on a nonbreeding ground, complicating the synchronizing effect of the environment. Migratory species show a variety of different strategies in how they disperse to and aggregate on nonbreeding grounds, ranging from completely shared nonbreeding grounds to multiple different ones. Depending on the sensitivity to environmental conditions off the breeding grounds, we can expect that migration and overwintering strategies will impact the extent and spatial pattern of population synchrony on the breeding grounds. Here, we use spatial population-dynamic modeling and simulations to investigate the relationship between seasonal environmental autocorrelation and migration characteristics. Our model shows that the effects of environmental autocorrelation experienced off the breeding ground on population synchrony depend on the number and size of nonbreeding grounds, and how populations migrate in relation to neighboring populations. When populations migrated to multiple nonbreeding grounds, spatial population synchrony increased with increasing environmental autocorrelation between nonbreeding grounds. Populations that migrated to the same place as near neighbors had higher synchrony at short distances than populations that migrated randomly. However, synchrony declined less across increasing distances for the random migration strategy. The differences in synchrony between migration strategies were most pronounced when the environmental autocorrelation between nonbreeding grounds was low. These results show the importance of considering migration when studying spatial population synchrony and predicting patterns of synchrony and population viability under global environmental change. Climate change and habitat loss and fragmentation may cause range shifts and changes in migratory strategies, as well as changes in the mean and spatial autocorrelation of the environment, which can alter the scale and patterns observed in spatial population synchrony.

Space weather disrupts nocturnal bird migration

Space weather, including solar storms, can impact Earth by disturbing the geomagnetic field. Despite the known dependence of birds and other animals on geomagnetic cues for successful seasonal migrations, the potential effects of space weather on organisms that use Earth's magnetic field for navigation have received little study. We tested whether space weather geomagnetic disturbances are associated with disruptions to bird migration at a macroecological scale. We leveraged long-term radar data to characterize the nightly migration dynamics of the nocturnally migrating North American avifauna over 22 y. We then used concurrent magnetometer data to develop a local magnetic disturbance index associated with each radar station (ΔBmax), facilitating spatiotemporally explicit analyses of the relationship between migration and geomagnetic disturbance. After controlling for effects of atmospheric weather and spatiotemporal patterns, we found a 9 to 17% decrease in migration intensity in both spring and fall during severe space weather events. During fall migration, we also found evidence for decreases in effort flying against the wind, which may represent a depression of active navigation such that birds drift more with the wind during geomagnetic disturbances. Effort flying against the wind in the fall was most reduced under both overcast conditions and high geomagnetic disturbance, suggesting that a combination of obscured celestial cues and magnetic disturbance may disrupt navigation. Collectively, our results provide evidence for community-wide avifaunal responses to geomagnetic disturbances driven by space weather during nocturnal migration.

Structural genomic variation and migratory behavior in a wild songbird.

Structural variants (SVs) are a major source of genetic variation; and descriptions in natural populations and connections with phenotypic traits are beginning to accumulate in the literature. We integrated advances in genomic sequencing and animal tracking to begin filling this knowledge gap in the Eurasian blackcap. Specifically, we (a) characterized the genome-wide distribution, frequency, and overall fitness effects of SVs using haplotype-resolved assemblies for 79 birds, and (b) used these SVs to study the genetics of seasonal migration. We detected >15 K SVs. Many SVs overlapped repetitive regions and exhibited evidence of purifying selection suggesting they have overall deleterious effects on fitness. We used estimates of genomic differentiation to identify SVs exhibiting evidence of selection in blackcaps with different migratory strategies. Insertions and deletions dominated the SVs we identified and were associated with genes that are either directly (e.g., regulatory motifs that maintain circadian rhythms) or indirectly (e.g., through immune response) related to migration. We also broke migration down into individual traits (direction, distance, and timing) using existing tracking data and tested if genetic variation at the SVs we identified could account for phenotypic variation at these traits. This was only the case for 1 trait-direction-and 1 specific SV (a deletion on chromosome 27) accounted for much of this variation. Our results highlight the evolutionary importance of SVs in natural populations and provide insight into the genetic basis of seasonal migration.