scholarly journals Morphology of migration: Associations between wing shape, bill morphology, and migration in kingbirds (Tyrannus)

2021 ◽  
Author(s):  
Maggie MacPherson ◽  
Alex Jahn ◽  
Nicholas A Mason
Keyword(s):  
Energy Expenditure ◽  
Long Distance ◽  
Migration Strategy ◽  
Dietary Specialization ◽  
Seasonal Movements ◽  
Bill Morphology ◽  
Pan American ◽  
Migratory Status ◽  
And Migration ◽  
Intraspecific Morphological Variation

Morphology is closely linked to locomotion and diet in animals. In animals that undertake long-distance migrations, limb-morphology is under selection to maximize mobility and minimize energy expenditure. Migratory behaviors also interact with diet, such that migratory animals tend to be dietary generalists, while sedentary taxa tend to be dietary specialists. Despite a hypothesized link between migration status and morphology, phylogenetic comparative studies have yielded conflicting findings. In this study, we tested for evolutionary associations between migratory status and limb and bill morphology across kingbirds, a pan-American genus of birds with migratory, partially migratory, and sedentary taxa. We found that migratory kingbirds had longer and more pointed wings, in agreement with expectations if selection favors improved aerodynamics for long-distance migration. We also found an association between migratory status and bill shape, such that more migratory taxa had wider and deeper bills and sedentary taxa had longer bills. However, there was no difference in levels of intraspecific morphological variation among migrants, partial migrants, and residents, suggesting that dietary specialization has evolved independently of migration strategy. Evolutionary links between migration, diet, and morphology in kingbirds further strengthen ecomorphological associations that underlie long-distance seasonal movements in animals.

scholarly journals Simple rules guide dragonfly migration

2006 ◽  
Vol 2 (3) ◽  
pp. 325-329 ◽  
Author(s):  
Martin Wikelski ◽  
David Moskowitz ◽  
James S Adelman ◽  
Jim Cochran ◽  
David S Wilcove ◽  
...  
Keyword(s):  
Decision Rules ◽  
Population Level ◽  
Long Distance ◽  
Migration Strategy ◽  
Anax Junius ◽  
Wind Speeds ◽  
Radio Transmitters ◽  
Migratory Patterns ◽  
And Migration ◽  
Made In

Every year billions of butterflies, dragonflies, moths and other insects migrate across continents, and considerable progress has been made in understanding population-level migratory phenomena. However, little is known about destinations and strategies of individual insects. We attached miniaturized radio transmitters ( ca 300 mg) to the thoraxes of 14 individual dragonflies (common green darners, Anax junius ) and followed them during their autumn migration for up to 12 days, using receiver-equipped Cessna airplanes and ground teams. Green darners exhibited distinct stopover and migration days. On average, they migrated every 2.9±0.3 days, and their average net advance was 58±11 km in 6.1±0.9 days (11.9±2.8 km d −1 ) in a generally southward direction (186±52°). They migrated exclusively during the daytime, when wind speeds were less than 25 km h −1 , regardless of wind direction, but only after two nights of successively lower temperatures (decrease of 2.1±0.6 °C in minimum temperature). The migratory patterns and apparent decision rules of green darners are strikingly similar to those proposed for songbirds, and may represent a general migration strategy for long-distance migration of organisms with high self-propelled flight speeds.

scholarly journals Variability and repeatability of noctule bat migration in Central Europe: evidence for partial and differential migration

2018 ◽  
Vol 285 (1893) ◽  
pp. 20182174 ◽  
Author(s):  
Linn S. Lehnert ◽  
Stephanie Kramer-Schadt ◽  
Tobias Teige ◽  
Uwe Hoffmeister ◽  
Ana Popa-Lisseanu ◽  
...  
Keyword(s):  
Central Europe ◽  
Migratory Behaviour ◽  
Natal Philopatry ◽  
Differential Migration ◽  
Long Distance ◽  
Migration Strategy ◽  
Migration Patterns ◽  
Bat Migration ◽  
Source Populations ◽  
And Migration

Each year, large numbers of bats move across Europe between their summer and winter areas, yet even though many of them are endangered and legally protected, we are unaware about many aspects of their migratory behaviour. Here, taking Nyctalus noctula as a model species, we used stable hydrogen isotopic values in fur ( δ 2 H f ) as an endogenous marker to shed light on the migratory behaviour of more than 1000 bats from hibernacula across Central Europe. Specifically, we asked the following questions: how flexible is migration in temperate zone bats? Which general migration pattern do noctule bats follow? How repeatable and thus predictable is the migratory behaviour of individuals? Do morphological correlates of migration occur in bats? Our study confirmed that noctule bats engage in partial and female-biased migration across Europe, suggesting the strongest migration pressures for northern populations. Further, we revealed a combination of partial and differential migration patterns with highly variable migration distances which lead to a pronounced mixing of different source populations in hibernacula where mating occurs. Most individuals were consistent in their migration strategy over time, i.e. 86% could be repeatedly assigned to either long-distance or regional origin across years. This is consistent with our finding that the between-individual component explained 84% of the variation in δ 2 H f values, suggesting specialized individual migratory behaviours and a strong natal philopatry. We discovered a positive correlation between forearm length and migration distance and support for sex-specific effects of migration on body condition. Our study elucidated migration patterns over large geographical scales, demonstrating that considerable numbers of migratory bats originating from distant populations depend on hibernacula across Central Europe, calling for international conservation management.

scholarly journals Adaptations to migration in birds: behavioural strategies, morphology and scaling effects

2007 ◽  
Vol 363 (1490) ◽  
pp. 287-299 ◽  
Author(s):  
Anders Hedenström
Keyword(s):  
Fuel Load ◽  
Scaling Effects ◽  
Annual Life Cycle ◽  
Long Distance ◽  
Migration Strategy ◽  
Stopover Site ◽  
Optimal Migration ◽  
Migration Theory ◽  
Time Minimization ◽  
And Migration

The annual life cycle of many birds includes breeding, moult and migration. All these processes are time and energy consuming and the extent of investment in any one may compromise the others. The output from breeding is of course the ultimate goal for all birds, while the investment in moult and migration should be selected so that lifetime fitness is maximized. In particular, long-distance migrants breeding at high latitudes face severe time pressures, which is a probable reason why natural selection has evolved efficient behaviours, physiological and morphological adaptations allowing the maximum possible migration speed. Optimal migration theory commonly assumes time minimization as an overall strategy, but the minimization of energy cost and predation risk may also be involved. Based on these assumptions, it is possible to derive adaptive behaviours such as when and at which fuel load a stopover site should be abandoned. I review some core components of optimal migration theory together with some key predictions. A review of accumulated empirical tests of the departure rule indicates that time minimization is an important component of the overall migration strategy, and hence gives support to the assumption about time-selected migration. I also briefly discuss how the optimal policy may be implemented by the bird by applying a set of simple rules. The time constraints on migrants increase with increasing body size. Some consequences of this are discussed.

Systematics, Biogeography, and Morphological Character Evolution of the Hemiepiphytic Subfamily Monsteroideae (Araceae)

2019 ◽  
Vol 104 (1) ◽  
pp. 33-48 ◽  
Author(s):  
Alejandro Zuluaga ◽  
Martin Llano ◽  
Ken Cameron
Keyword(s):  
Dna Sequences ◽  
Pacific Islands ◽  
R Package ◽  
Morphological Characters ◽  
Ancestral State ◽  
Seed Shape ◽  
Long Distance ◽  
The Pacific ◽  
And Migration ◽  
The Tropics

The subfamily Monsteroideae (Araceae) is the third richest clade in the family, with ca. 369 described species and ca. 700 estimated. It comprises mostly hemiepiphytic or epiphytic plants restricted to the tropics, with three intercontinental disjunctions. Using a dataset representing all 12 genera in Monsteroideae (126 taxa), and five plastid and two nuclear markers, we studied the systematics and historical biogeography of the group. We found high support for the monophyly of the three major clades (Spathiphylleae sister to Heteropsis Kunth and Rhaphidophora Hassk. clades), and for six of the genera within Monsteroideae. However, we found low rates of variation in the DNA sequences used and a lack of molecular markers suitable for species-level phylogenies in the group. We also performed ancestral state reconstruction of some morphological characters traditionally used for genera delimitation. Only seed shape and size, number of seeds, number of locules, and presence of endosperm showed utility in the classification of genera in Monsteroideae. We estimated ancestral ranges using a dispersal-extinction-cladogenesis model as implemented in the R package BioGeoBEARS and found evidence for a Gondwanan origin of the clade. One tropical disjunction (Monstera Adans. sister to Amydrium Schott–Epipremnum Schott) was found to be the product of a previous Boreotropical distribution. Two other disjunctions are more recent and likely due to long-distance dispersal: Spathiphyllum Schott (with Holochlamys Engl. nested within) represents a dispersal from South America to the Pacific Islands in Southeast Asia, and Rhaphidophora represents a dispersal from Asia to Africa. Future studies based on stronger phylogenetic reconstructions and complete morphological datasets are needed to explore the details of speciation and migration within and among areas in Asia.

scholarly journals Prevalence and genetic diversity of avian haemosporidian parasites in wild bird species of the order Columbiformes

2021 ◽  
Author(s):  
Yvonne R. Schumm ◽  
Dimitris Bakaloudis ◽  
Christos Barboutis ◽  
Jacopo G. Cecere ◽  
Cyril Eraud ◽  
...  
Keyword(s):  
Host Species ◽  
Large Scale ◽  
Phylogenetic Reconstruction ◽  
Bird Species ◽  
Avian Species ◽  
Blood Parasites ◽  
Migration Strategy ◽  
Haemosporidian Parasites ◽  
Multiplex Pcr Assay ◽  
And Migration

AbstractDiseases can play a role in species decline. Among them, haemosporidian parasites, vector-transmitted protozoan parasites, are known to constitute a risk for different avian species. However, the magnitude of haemosporidian infection in wild columbiform birds, including strongly decreasing European turtle doves, is largely unknown. We examined the prevalence and diversity of haemosporidian parasites Plasmodium, Leucocytozoon and subgenera Haemoproteus and Parahaemoproteus in six species of the order Columbiformes during breeding season and migration by applying nested PCR, one-step multiplex PCR assay and microscopy. We detected infections in 109 of the 259 screened individuals (42%), including 15 distinct haemosporidian mitochondrial cytochrome b lineages, representing five H. (Haemoproteus), two H. (Parahaemoproteus), five Leucocytozoon and three Plasmodium lineages. Five of these lineages have never been described before. We discriminated between single and mixed infections and determined host species-specific prevalence for each parasite genus. Observed differences among sampled host species are discussed with reference to behavioural characteristics, including nesting and migration strategy. Our results support previous suggestions that migratory birds have a higher prevalence and diversity of blood parasites than resident or short-distance migratory species. A phylogenetic reconstruction provided evidence for H. (Haemoproteus) as well as H. (Parahaemoproteus) infections in columbiform birds. Based on microscopic examination, we quantified parasitemia, indicating the probability of negative effects on the host. This study provides a large-scale baseline description of haemosporidian infections of wild birds belonging to the order Columbiformes sampled in the northern hemisphere. The results enable the monitoring of future changes in parasite transmission areas, distribution and diversity associated with global change, posing a potential risk for declining avian species as the European turtle dove.

War Captives, Left-Behind Wives, and Buddhist Nuns: Female Migrants in Early Medieval China (4th–6th Century CE)

2021 ◽  
pp. 1-18
Author(s):  
Wen-Yi Huang
Keyword(s):  
Fourth Century ◽  
Early Medieval ◽  
Long Distance ◽  
Textual Representations ◽  
Medieval China ◽  
Gender And Migration ◽  
Early Medieval China ◽  
And Migration ◽  
Northern Wei ◽  
Distance Travel

Abstract Using received texts and excavated funerary epitaphs, this article examines the intricacies of gender and migration in early medieval China by exploring women's long-distance mobility from the fourth century to the sixth century, when what is now known as China was divided by the Northern Wei and a succession of four southern states—the Eastern Jin, Liu-Song, Southern Qi, and Liang. I focus on three types of migration in which women participated during this period: war-induced migration, family reunification, and religious journeys. Based on this analysis, I propose answers to two important questions: the connection between migration and the state, and textual representations of migrants. Though the texts under consideration are usually written in an anecdotal manner, the references to women, I argue, both reveals nuances in perceptions of womanhood at the time and elucidates the contexts within—and through—which long-distance travel became possible for women.

scholarly journals Great flights by great snipes: long and fast non-stop migration over benign habitats

2011 ◽  
Vol 7 (6) ◽  
pp. 833-835 ◽  
Author(s):  
Raymond H. G. Klaassen ◽  
Thomas Alerstam ◽  
Peter Carlsson ◽  
James W. Fox ◽  
Åke Lindström
Keyword(s):  
Migratory Birds ◽  
Strenuous Exercise ◽  
Migration Route ◽  
Long Distance ◽  
Migration Strategy ◽  
Ice Caps ◽  
Fuel Loads ◽  
Stopover Sites ◽  
Ecological Barriers ◽  
Suitable Habitats

Migratory land birds perform extreme endurance flights when crossing ecological barriers, such as deserts, oceans and ice-caps. When travelling over benign areas, birds are expected to migrate by shorter flight steps, since carrying the heavy fuel loads needed for long non-stop flights comes at considerable cost. Here, we show that great snipes Gallinago media made long and fast non-stop flights (4300–6800 km in 48–96 h), not only over deserts and seas but also over wide areas of suitable habitats, which represents a previously unknown migration strategy among land birds. Furthermore, the great snipes achieved very high ground speeds (15–27 m s −1 ), which was not an effect of strong tailwind support, and we know of no other animal that travels this rapidly over such a long distance. Our results demonstrate that some migratory birds are prepared to accept extreme costs of strenuous exercise and large fuel loads, even when stopover sites are available along the route and there is little tailwind assistance. A strategy of storing a lot of energy before departure, even if migration is over benign habitats, may be advantageous owing to differential conditions of fuel deposition, predation or infection risk along the migration route.

scholarly journals The dematerialization of telecommunication: communication centres and peripheries in Europe and the world, 1850–1920

2007 ◽  
Vol 2 (3) ◽  
pp. 345-372 ◽  
Author(s):  
Roland Wenzlhuemer
Keyword(s):  
Telecommunication Network ◽  
Local Development ◽  
Global Communication ◽  
Communication Structure ◽  
Long Distance ◽  
Interregional Trade ◽  
Distance Information ◽  
History Information ◽  
And Migration ◽  
Global Data

AbstractInterregional communication has been a key constituent of the process of globalization since its very origins. For most of its history, information has moved between world regions and along the routes according to the rationales established by interregional trade and migration. The dematerialization of telecommunication in the late eighteenth and nineteenth century eventually detached long-distance information transmission from transport and transformed the global communication structure. New communication centres (and new peripheries) emerged. Some regions moved closer to the global data stream than others. It is still unclear how such different degrees of global connectivity impacted on local development. This essay contributes to the identification and valuation of global communication centres and peripheries in order to provide suitable candidates for future case studies. To this end, statistical data on the development of domestic telegraph networks in selected countries has been analysed and interpreted. In a second step, Social Network Analysis methods have been employed to measure the centrality of almost three hundred cities and towns in the European telecommunication network of the early twentieth century.‘You cannot not communicate.’Paul Watzlawick

scholarly journals On the interrelations between migration and commuting

Stanovnistvo ◽  
2013 ◽  
Vol 51 (1) ◽  
pp. 69-90 ◽  
Author(s):  
Vesna Lukic
Keyword(s):  
Real Estate ◽  
Labour Market ◽  
Real Estate Market ◽  
Modern Trend ◽  
Population Mobility ◽  
Rural Settlements ◽  
Long Distance ◽  
And Migration ◽  
Vojvodina Province

In this paper, we emphasise the significance of studying the interrelations between commuting and migration. The aim of the paper is to point out the factors which affect these interrelations (demographic and socio-economic characteristics of migrants and commuters, labour market, real estate market, information, life style, etc.), with the special emphasis on the role of commuting distance onto the chosen mobility type. Besides theorethical frameworks and results of the selected foreign researches up to date, the overview of research of interrelations between migration and commuting in Serbia has also been presented. While earlier studies conducted by Gawryszenski (1978), Termote (1980) and Reitsma&Vergoossen (1987) pointed to the replacement of migration types between each other within country, in recent literature the interaction between migration and commuting has been studied in a trans-boundary context of the contemporary EU. Modern trend of long distance commuting instead of migration and the concept of substitution/replacement regarding migration and commuting have also been discussed. In Serbia, there is a positive correlation between commuting outflows and immigration in rural settlements of Vojvodina province. Namely, commuting and migration are complement, which is the characteristic of both processes sub-urbanisation and ex-urbanisation (Lukic, 2012). In addition to ownership of real estate and previous migration experience, marital status influenced the chosen mobility type in Serbia as well. Adjustment to changes of Serbian labour market is mostly conducted via migration (Miletic, Lukic, Miljanovic, 2011). Interrelations between migration and commuting are very significant due to the tendency of transformation of some commuters into migrants. This process has its consequences, both on demographic as well as the overall socio-economic development of the area of commuters? origin and destination. However, even though the surveys conducted in Serbia during the 1980s showed that around 30 per cent of commuters expressed desire to move to their place of work, the degree of realization of these intentions remained unknown. While in some countries traffic studies and data from the management of the enterprises are used as sources of data on commuting, the studies on the commuter population in Serbia are based solely onto two types of data sources. These are census and poll surveys. Although they have more potential than the official statistics for the analysis of the links between migration and commuting and other characteristics of commuters, poll surveys on this topic in Serbia are relatively rare due to financial and organizational obstacles. Indeed, the last major survey was conducted in the 1980s. Therefore, even though the interrelations between migration and commuting have been confirmed, there is still a lot of space for their research indicating the need for further methodology developments in researching these types of population mobility.

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