scholarly journals Long-distance autumn migration across the Sahara by painted lady butterflies: exploiting resource pulses in the tropical savannah

2016 ◽  
Vol 12 (10) ◽  
pp. 20160561 ◽  
Author(s):  
Constantí Stefanescu ◽  
David X. Soto ◽  
Gerard Talavera ◽  
Roger Vila ◽  
Keith A. Hobson
Keyword(s):  
North Africa ◽  
Hydrogen Isotope ◽  
African Countries ◽  
Long Distance ◽  
European Origin ◽  
Resource Pulses ◽  
Vanessa Cardui ◽  
Stable Hydrogen Isotope ◽  
Mixed Origin ◽  
Northwestern Africa

The painted lady, Vanessa cardui , is a migratory butterfly that performs an annual multi-generational migration between Europe and North Africa. Its seasonal appearance south of the Sahara in autumn is well known and has led to the suggestion that it results from extremely long migratory flights by European butterflies to seasonally exploit the Sahel and the tropical savannah. However, this possibility has remained unproven. Here, we analyse the isotopic composition of butterflies from seven European and seven African countries to provide new support for this hypothesis. Each individual was assigned a geographical natal origin, based on its wing stable hydrogen isotope (δ 2 H w ) value and a predicted δ 2 H w basemap for Europe and northern Africa. Natal assignments of autumn migrants collected south of the Sahara confirmed long-distance movements (of 4000 km or more) starting in Europe. Samples from Maghreb revealed a mixed origin of migrants, with most individuals with a European origin, but others having originated in the Sahel. Therefore, autumn movements are not only directed to northwestern Africa, but also include southward and northward flights across the Sahara. Through this remarkable behaviour, the productive but highly seasonal region south of the Sahara is incorporated into the migratory circuit of V. cardui .

scholarly journals Round-trip across the Sahara: Afrotropical Painted Lady butterflies recolonize the Mediterranean in early spring

2018 ◽  
Vol 14 (6) ◽  
pp. 20180274 ◽  
Author(s):  
Gerard Talavera ◽  
Clément Bataille ◽  
Dubi Benyamini ◽  
Martin Gascoigne-Pees ◽  
Roger Vila
Keyword(s):  
Hydrogen Isotope ◽  
Migratory Birds ◽  
Early Spring ◽  
Round Trip ◽  
Reverse Migration ◽  
Vanessa Cardui ◽  
Tangible Evidence ◽  
Stable Hydrogen Isotope ◽  
Sub Saharan ◽  
Work Supports

The Palearctic–African migratory circuit has been typically associated with birds. Very few insects are known to endure annual trans-Saharan circuits, but the Painted Lady butterfly ( Vanessa cardui ) is an exception. While it was demonstrated that this species massively migrates from Europe to the Afrotropics during the autumn, the existence of a reverse migration from the Afrotropics to Europe in the early spring remains hypothetical. Here, we analysed wing stable hydrogen isotope values (δ 2 H) of V. cardui migrants collected from February to April across the circum-Mediterranean region. We assessed their region of natal origin by comparing their wing isotope signature predicted δ 2 H values (isoscape). The results unambiguously demonstrate a sub-Saharan origin for many individuals, especially those collected in February, representing the first tangible evidence for a reverse northwards trans-Saharan migration in spring. This work supports the view that the Afrotropics (mostly exploited from September to February) is key in the V. cardui Palearctic–African population dynamics. This species relies on both temperate and tropical habitats to complete their multigenerational cycle, an unprecedented adaptation for butterflies and for most migratory insects. Such a migratory circuit has strong parallelisms with those of migratory birds.

scholarly journals STABLE HYDROGEN ISOTOPE ANALYSIS OF BAT HAIR AS EVIDENCE FOR SEASONAL MOLT AND LONG-DISTANCE MIGRATION

2004 ◽  
Vol 85 (5) ◽  
pp. 995-1001 ◽  
Author(s):  
Paul M. Cryan ◽  
Michael A. Bogan ◽  
Robert O. Rye ◽  
Gary P. Landis ◽  
Cynthia L. Kester
Keyword(s):  
Hydrogen Isotope ◽  
Isotope Analysis ◽  
Long Distance ◽  
Stable Hydrogen Isotope

scholarly journals Origins of Six Species of Butterflies Migrating through Northeastern Mexico: New Insights from Stable Isotope (δ2H) Analyses and a Call for Documenting Butterfly Migrations

Diversity ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 102
Author(s):  
Keith A. Hobson ◽  
Jackson W. Kusack ◽  
Blanca X. Mora-Alvarez
Keyword(s):  
Stable Isotope ◽  
Global Change ◽  
Hydrogen Isotope ◽  
Migratory Connectivity ◽  
Concerted Effort ◽  
Long Distance ◽  
Present Evidence ◽  
Danaus Gilippus ◽  
Northeastern Mexico ◽  
Stable Hydrogen Isotope

Determining migratory connectivity within and among diverse taxa is crucial to their conservation. Insect migrations involve millions of individuals and are often spectacular. However, in general, virtually nothing is known about their structure. With anthropogenically induced global change, we risk losing most of these migrations before they are even described. We used stable hydrogen isotope (δ2H) measurements of wings of seven species of butterflies (Libytheana carinenta, Danaus gilippus, Phoebis sennae, Asterocampa leilia, Euptoieta claudia, Euptoieta hegesia, and Zerene cesonia) salvaged as roadkill when migrating in fall through a narrow bottleneck in northeast Mexico. These data were used to depict the probabilistic origins in North America of six species, excluding the largely local E. hegesia. We determined evidence for long-distance migration in four species (L. carinenta, E. claudia, D. glippus, Z. cesonia) and present evidence for panmixia (Z. cesonia), chain (Libytheana carinenta), and leapfrog (Danaus gilippus) migrations in three species. Our investigation underlines the utility of the stable isotope approach to quickly establish migratory origins and connectivity in butterflies and other insect taxa, especially if they can be sampled at migratory bottlenecks. We make the case for a concerted effort to atlas butterfly migrations using the stable isotope approach.

scholarly journals The COVID-19 Outbreak in North Africa: A Legal Analysis

2021 ◽  
pp. 002190962098358
Author(s):  
Francesco Tamburini
Keyword(s):  
Population Health ◽  
North Africa ◽  
Democratic Institutions ◽  
Legal Analysis ◽  
North African ◽  
African Countries ◽  
Health Security ◽  
Legislative Measures

North African nations, especially Egypt, Algeria, and Morocco, have been heavily affected by COVID-19 if compared to other African countries. Governments in North Africa took proactive legal measures to manage the virus threat, safeguarding population health, but also triggering repressive and invasive mechanisms that in some cases jeopardized basic freedoms and rights. This work will analyze comparatively the anti-COVID-19 legislations, pointing out how the legislative measures mirrored the level of transition of democracy, the opacity of some regimes, exploitation of the pandemic to foster repressive control, and highlighting the weakness of new democratic institutions unprepared to balance health security and democracy.

scholarly journals Mass spectrometric measurement of hydrogen isotope fractionation for the reactions of chloromethane with OH and Cl

2018 ◽  
Author(s):  
Frank Keppler ◽  
Enno Bahlmann ◽  
Markus Greule ◽  
Heinz Friedrich Schöler ◽  
Julian Wittmer ◽  
...  
Keyword(s):  
Hydrogen Isotope ◽  
Isotope Fractionation ◽  
Isotope Effects ◽  
Isotope Analysis ◽  
Isotope Ratio Mass Spectrometry ◽  
Detailed Knowledge ◽  
Mass Spectrometric Measurement ◽  
Isotopic Analyses ◽  
Chlorine Radicals ◽  
Stable Hydrogen Isotope

Abstract. Chloromethane (CH3Cl) is an important provider of chlorine to the stratosphere but yet lacks detailed knowledge of its budget. Stable isotope analysis is potentially a powerful tool to constrain CH3Cl flux estimates. The largest degree of isotope fractionation is expected to occur for deuterium in CH3Cl in the hydrogen abstraction reactions with its main sink reactant tropospheric OH and its minor sink reactant Cl atoms. We determined the isotope fractionation by stable hydrogen isotope analysis of the fraction of CH3Cl remaining after reaction with hydroxyl and chlorine radicals in a 3.5 m3 Teflon smog-chamber at 293 ± 1 K. We measured the increasing stable hydrogen isotope values of the unreacted CH3Cl using compound specific thermal conversion isotope ratio mass spectrometry. The isotope fractionations of CH3Cl for the reactions with hydroxyl and chlorine radicals were found to be −242 ± 7 mUr (or ‰) and −280 ± 11 mUr, respectively. For comparison, we performed similar experiments using methane (CH4) as the target compound with OH and obtained a fractionation constant of −205 ± 6 mUr which is in good agreement with values previously reported. The observed large kinetic isotope effects are helpful when employing isotopic analyses of CH3Cl in the atmosphere to improve our knowledge of its atmospheric budget.

Slavery and the Slave Trade in Dār Fūr

1973 ◽  
Vol 14 (1) ◽  
pp. 29-43 ◽  
Author(s):  
R. S. O'Fahey
Keyword(s):  
State Formation ◽  
North Africa ◽  
Central African Republic ◽  
Slave Trade ◽  
The State ◽  
The South ◽  
Ruling Elite ◽  
Long Distance ◽  
State Organization ◽  
Slave Raid

The institutions of slavery, slave raiding and the slave trade were fundamental in the rise and expansion of the Keira Sultanate of Dār Fūr. The development of a long-distance trade in slaves may be due to immigrants from the Nile, who probably provided the impetus to state formation. This process may be remembered in the ‘Wise Stranger’ traditions current in the area. The slave raid or ghazwa, penetrating into the Baḥr al-Ghazāl and what is now the Central African Republic, marked the triumph of Sudanic state organization over the acephalous societies to the south.The slaves, who were carefully classified, were not only exported to Egypt and North Africa, but also served the sultans and the title-holding elite as soldiers, labourers and bureaucrats. In the latter role, the slaves began to encroach on the power of traditional ruling groups within the state; the conflict between the slave bureaucrats and the traditional ruling elite lasted until the end of the first Keira Sultanate in 1874.

scholarly journals Environmental Performance and Economic Growth in Middle East and North Africa Countries

2019 ◽  
Vol 9 (24) ◽  
Author(s):  
Hichem Dkhili
Keyword(s):  
Economic Growth ◽  
Middle East ◽  
North Africa ◽  
Environmental Performance ◽  
Middle Eastern ◽  
Smooth Transition ◽  
African Countries ◽  
Mena Region ◽  
Mena Countries ◽  
The Impact

Background. Studies on environmental performance/quality and economic growth show inconclusive results. Objective. The aim of the present study is to assess the non-linear relationship between environmental performance and economic growth in the Middle East and North Africa (MENA) region from 2002–2018. Methods. A sample of fourteen (14) MENA countries was used in the present analysis. However, due to important differences between countries in this region, the whole sample was divided into two sub-samples; nine Middle Eastern countries (MEAS) and five North African countries (NAF). We performed the panel smooth transition regression model as an econometric approach. Discussion. Empirical results indicate a threshold effect in the environmental performance and economic growth relationship. The threshold value differs from one group of countries to another. More specifically, we found that the impact of environmental performance and economic growth is positive and significant only if a certain threshold level has been attained. Until then, the effect remains negative. Conclusions. The findings of the present study are of great importance for policymakers since they determine the optimal level of environmental performance required to act positively on the level of economic growth. MENA countries should seek to improve their environmental performance index in order to grow output. Competing Interests. The authors declare no competing financial interests.

scholarly journals Acordos entre Espanha e países do Norte da África como mecanismos de controle das migrações irregulares nos anos 2000 | Agreements between Spain and North African countries as a mechanism of irregular migration control in the 2000s

2021 ◽  
Vol 12 ◽  
pp. e59962
Author(s):  
Ana Beatriz Da Costa Mangueira ◽  
Filipe Reis Melo
Keyword(s):  
North Africa ◽  
The European Union ◽  
European Security ◽  
Labor Costs ◽  
North African ◽  
African Countries ◽  
Foreign Labor ◽  
The Moment ◽  
North African Countries ◽  
The Relationship

Este artigo analisa como a Espanha securitizou fluxos migratórios irregulares do Norte da África na primeira década dos anos 2000. Esse processo realizou-se com medidas de segurança nas fronteiras, especialmente nas regiões de Ceuta e Melila. Por outro lado, os governos espanhóis ao longo daquela década reavivaram acordos firmados com os africanos ainda nos anos 1990 para readmissão de migrantes e para admissão de indivíduos no mercado de trabalho espanhol. A relação entre Espanha e países africanos foi contraditória, pois enquanto se buscava conter as migrações indesejadas, pretendia-se usar a mão de obra estrangeira para reduzir os custos trabalhistas. Essas contradições são influenciadas pela presença da União Europeia que delibera e atua na temática de migrações na região, um assunto que tem sido um dos principais interesses da agenda de segurança europeia nos últimos anos. Palavras-Chave: Espanha. Fluxos migratórios. Norte da África. ABSTRACTThis paper analyses how Spain securitized irregular migratory flows from North Africa in the 2000s first decade. This process was carried out by security actions at the borders, specially at Ceuta and Melilla regions. On other hand, over the years of 2000s Spanish governments renewed agreements that were signed with Africans in the 1990s to foster readmission of migrants and promote the admission of individuals to the Spanish labor market. Furthermore, the relationship between Spain and African countries was inconsistent due to the fact that at the moment which the contention of unwanted migration was the focus, it was intended to use foreign labor to reduce labor costs. These contradictions are influenced by the presence of the European Union, which deliberates and acts on the issue of migration in the region, a subject that has been one of the main interests of the European security agenda in recent years. Keywords: Spain. Migration flows. North Africa. Recebido em: 24 mai. 2021 | Aceito em: 01 out. 2021.

scholarly journals Enteric Fever in Mediterranean North Africa

2009 ◽  
Vol 3 (10) ◽  
pp. 753-761 ◽  
Author(s):  
Khalifa Sifaw Ghenghesh ◽  
Ezzedin Franka ◽  
Khaled Tawil ◽  
Momtaz Wasfy ◽  
Salwa F. Ahmed ◽  
...  
Keyword(s):  
North Africa ◽  
Salmonella Enterica ◽  
Enteric Fever ◽  
Salmonella Typhi ◽  
Multidrug Resistant ◽  
Population Based ◽  
North African ◽  
African Region ◽  
African Countries ◽  
The Mediterranean

Typhoid fever is endemic in the Mediterranean North African countries (Morocco, Algeria, Tunisia, Libya, and Egypt) with an estimated incidence of 10-100 cases per 100,000 persons. Outbreaks caused by Salmonella enterica serovar Typhi are common and mainly due to the consumption of untreated or sewage-contaminated water. Salmonella enterica Paratyphi B is more commonly involved in nosocomial cases of enteric fever in North Africa than expected and leads to high mortality rates among infants with congenital anomalies. Prevalence among travellers returning from this region is low, with an estimate of less than one per 100,000. Although multidrug resistant strains of Salmonella Typhi and Paratyphi are prevalent in this region, the re-emergence of chloramphenicol- and ampicillin-susceptible strains has been observed. In order to better understand the epidemiology of enteric fever in the Mediterranean North African region, population-based studies are needed. These will assist the health authorities in the region in preventing and controlling this important disease.

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