The results of trapping, measuring the size and weight of the body of the European Nightjar, as well as migration routes according to the data of the ringing in the Kaliningrad region during ...1957–2016 are discussed. The annual number of migrating birds has fluctuated significantly for 60 years, and the number of those caught and ringed varied from one to 44 individuals in different years. They were most numerous in May, in the period 1969–1981. Four ring recoveries of Nightjars ringed by us were obtained, which gives the effectiveness of ringing of this species with nocturnal activity of only 0.92%. However, these ringing results indicate that in autumn the migration routes of Nightjar population from the western parts of Scandinavia and from southern Finland run through the eastern coast of the Baltic Sea, and later, on the way to Africa, their azimuth of flight varies from 178° to 203°. The longevity record according to the data from one male of the subspecies Caprimulgus europaeus zarudny E. Hartert, 1912 was 15 years. The migration routes of this species are discussed according to the latest literature data.
Based on the results of trapping and ringing Yellow Wagtail on the Courish (Curonian) Spit in Eastern Baltic in the amount of 3076 individuals during 1957–2020, the population numbers, the migration ...routes and wintering grounds are presented. The obtained seven recoveries of our rings account for only 0.23% of the efficiency of Yellow Wagtail ringing. The annual number of Yellow Wagtails captured varied widely over 64 years, from three to 206 individuals. The oscillations were wavelike in nature and showed different amplitudes. Of the seven birds with our rings found two birds in November and February were caught in the Federal Republic of Nigeria (West Africa), three birds during migration were found in Italy and two birds during the summer were found in Sweden and Finland. The length of the migration route from the Courish Spit to Nigeria was more than five thousand kilometers. The results of studying the migrations of this species in other countries and regions are discussed.
Être une femme ou un homme étranger et noir et souffrir du froid, de la faim et de l’absence de sécurité, ne pas avoir d'existence sociale reconnue : telle est l’expérience des personnes migrantes ...suivies durant cette enquête au Maroc. Leur point commun est de n’avoir, à certains moments de leur séjour, plus qu'une seule et ultime ressource : leur propre corps. À partir d’une enquête ethnographique menée entre 2016 et 2020 et de l’analyse de corpus biographiques, cet article propose de revenir sur l’expérience vécue de la vulnérabilité extrême et sur les tactiques envisagées pour y faire face. Il présente une analyse centrée sur les corps des migrants conçus comme des surfaces sur lesquelles des « régimes de vérité » s’inscrivent, en tant que lieu de domination et de résistance créative.
Being a foreign, black woman or man, suffering from cold, hunger and lack of security, with no recognized social existence: this is the experience of the migrants we followed during this survey in Morocco. What they have in common is that, at certain points in their stay, they have only one ultimate resource left: their own bodies. Based on an ethnographic survey conducted between 2016 and 2020 and the analysis of biographical material, this article proposes to revisit the lived experience of extreme vulnerability and the tactics considered to cope with it. It presents an analysis centered on migrants’ bodies conceived as surfaces on which “regimes of truth” are inscribed, as sites of domination and creative resistance.
Abstract In recent years, the Mediterranean crossings have reconfirmed their status as the most perilous routes for migrants attempting to reach European shores, with a significantly high number of ...deaths. In response, the Italian government has implemented various strategies aimed at reducing the number of landings and controlling irregular migration. This research evaluates the impact of these measures on the dynamics of migrant smuggling, both qualitatively and quantitatively. It examines the effectiveness of these measures and their influence on the adaptation of routes, methods, and organization of criminal groups involved in smuggling. The study emphasizes that while the measures to curb irregular immigration have had a limited direct impact on overall migratory flows and primary routes, they have indirectly influenced smugglers’ strategies. The study is grounded in empirical data sourced from interviews with expert witnesses and judicial investigations conducted by Italian prosecutors, with a comprehensive analysis of quantitative data. The findings aim to contribute to a deeper understanding of the multifaceted nature of irregular migration in the Mediterranean and the impacts of policy interventions.
Many migratory species have experienced substantial declines that resulted from rapid and massive expansions of human structures and activities, habitat alterations and climate change. Migrants are ...also recognized as an integral component of biodiversity and provide a multitude of services and disservices that are relevant to human agriculture, economy and health. The plethora of recently published studies reflects the need for better fundamental knowledge on migrations and for better management of their ecological and human‐relevant effects. Yet, where are we in providing answers to fundamental questions and societal challenges?
Engaging a broad network of researchers worldwide, we used a horizon‐scan approach to identify the most important challenges which need to be overcome in order to gain a fuller understanding of migration ecology, and which could be addressed using radar aeroecological and macroecological approaches. The top challenges include both long‐standing and novel topics, ranging from fundamental information on migration routes and phenology, orientation and navigation strategies, and the multitude of effects migrants may have on resident communities, to societal challenges, such as protecting or preventing migrant services and disservices, and the conservation of migrants in the face of environmental changes. We outline these challenges, identify the urgency of addressing them and the primary stakeholders – researchers, policy makers and practitioners, or funders of research.
Drosophila buzzatii (Diptera: Drosophilidae) is a fly that breeds exclusively on decaying tissues of cacti species widely distributed in tropical and subtropical areas of South America. This ...distribution includes biomes in distinct climatic regimes (e.g., seasonal rain forest, semi-arid scrubs, savannas, and grasslands), which at first glance could might give the false impression that the species is not sensitive to either climate or vegetation physiognomies. However, detection of historical demographic events within D. buzzatii reveal the interplay between climate and the population structure of the species as the Late Quaternary climate changes occurred. To understand this process, we performed a phylogeographic analysis based on sequences of the mitochondrial gene COI for 128 individuals from 43 localities. Our analyses combined coalescent methods, population genetics, and paleodistributions estimation methods. Our study reveals that the COI haplotype diversity is geographically structured, with a decreasing cline from north to south. The results suggest an ancient range expansion, dated from 610k to 550k years before present, in the northernmost region of the species distribution, the Caatinga vegetation. More recently, an intense gene flow and a population expansion were detected in the central and south portions of its distribution. The demographic events detected date back to the glacial periods of the Quaternary.
The small size of the billions of migrating songbirds commuting between temperate breeding sites and the tropics has long prevented the study of the largest part of their annual cycle outside the ...breeding grounds. Using light-level loggers (geolocators), we recorded the entire annual migratory cycle of the red-backed shrike Lanius collurio, a trans-equatorial Eurasian-African passerine migrant. We tested differences between autumn and spring migration for nine individuals. Duration of migration between breeding and winter sites was significantly longer in autumn (average 96 days) when compared with spring (63 days). This difference was explained by much longer staging periods during autumn (71 days) than spring (9 days). Between staging periods, the birds travelled faster during autumn (356 km d–1) than during spring (233 km d–1). All birds made a protracted stop (53 days) in Sahelian sub-Sahara on southbound migration. The birds performed a distinct loop migration (22 000 km) where spring distance, including a detour across the Arabian Peninsula, exceeded the autumn distance by 22 per cent. Geographical scatter between routes was particularly narrow in spring, with navigational convergence towards the crossing point from Africa to the Arabian Peninsula. Temporal variation between individuals was relatively constant, while different individuals tended to be consistently early or late at different departure/arrival occasions during the annual cycle. These results demonstrate the existence of fundamentally different spatio-temporal migration strategies used by the birds during autumn and spring migration, and that songbirds may rely on distinct staging areas for completion of their annual cycle, suggesting more sophisticated endogenous control mechanisms than merely clock-and-compass guidance among terrestrial solitary migrants. After a century with metal-ringing, year-round tracking of long-distance migratory songbirds promises further insights into bird migration.
The Sahara Desert is one of the largest land-based barriers on the Earth, crossed twice each year by billions of birds on migration. Here we investigate how common swifts migrating between breeding ...sites in Sweden and wintering areas in sub-Saharan Africa perform the desert crossing with respect to route choice, winds, timing and speed of migration by analysing 72 geolocator tracks recording migration. The swifts cross western Sahara on a broad front in autumn, while in spring they seem to use three alternative routes across the Sahara, a western, a central and an eastern route across the Arabian Peninsula, with most birds using the western route. The swifts show slower migration and travel speeds, and make longer detours with more stops in autumn compared with spring. In spring, the stopover period in West Africa coincided with mostly favourable winds, but birds remained in the area, suggesting fuelling. The western route provided more tailwind assistance compared with the central route for our tracked swifts in spring, but not in autumn. The ultimate explanation for the evolution of a preferred western route is presumably a combination of matching rich foraging conditions (swarming insects) and favourable winds enabling fast spring migration.
This article is part of the themed issue ‘Moving in a moving medium: new perspectives on flight’.
In recent decades, several explanations for vagrancy of North Asian bird species in Europe have been suggested. The explanations can typically be divided into two, non‐exclusive groups. Some cite ...weather factors as the primary cause of vagrancy, whereas others hypothesize an internal defect behind the phenomenon. In addition, some authors also suggest climate‐driven range expansion following breeding population increase as a contributing factor. In recent years, studies have been published that have provided clear evidence for the origin of vagrant birds, as well as the reasons for their vagrancy. Here we summarize current knowledge and conclude that weather, habitat use, feeding habit, breeding success and climate change are important factors that affect the vagrancy of birds, together with the number of observers playing an important role in contributing data. In the future, advances in technology such as the development of tracking systems and the extensive use of stable isotopes will make it possible to explain the causes of vagrancy more precisely, so further research in this area of ornithology is essential.
The combination of population and landscape genetics can facilitate the understanding of conservation strategy under the changing climate. Here, we focused on the two most diverse and ecologically ...important evergreen oaks:
and
in Qinghai-Tibetan Plateau (QTP), which is considered as world's biodiversity hotspot. We genotyped 1,657 individuals of 106 populations at 15 nuclear microsatellite loci throughout the species distribution range. Spatial patterns of genetic diversity were identified by mapping the allelic richness (AR) and locally common alleles (LCA) according to the circular neighborhood methodology. Migration routes from QTP were detected by historical gene flow estimation. The response pattern of genetic variation to environmental gradient was assessed by the genotype-environment association (GEA) analysis. The overall genetic structure showed a high level of intra-species genetic divergence of a strong west-east pattern. The West-to-East migration route indicated the complex demographic history of two oak species. We found evidence of isolation by the environment in
-East and
-West lineage but not in
-West and
-East lineage. Furthermore, priority for conservation should be given to populations that retain higher spatial genetic diversity or isolated at the edge of the distribution range. Our findings indicate that knowledge of spatial diversity and migration route can provide valuable information for the conservation of existing populations. This study provides an important guide for species conservation for two oak species by the integration of population and landscape genetic methods.
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