Study Of Bird Migration Research Articles

Global Dynamics of Bird Migration: Trends, Mechanisms and Conservation Challenges

Global bird migration is a complex phenomenon influenced by a multitude of factors, including climate change, habitat loss, and human activities. This paper explores the trends in migratory patterns observed over recent decades, highlighting shifts in timing, routes, and species distributions Bird migrations are behavioural occurrences, exemplifying intricate spatiotemporal tactics to optimise living expenses while enhancing fitness. Birds express a range of migratory patterns, from highly predictable obligate migration, to less predictable nomadic and fugitive migrations. Despite significant advancements in bird migration studies, still certain essential gaps remain. Due to technological advancement, bird migration studies have uncovered significant insights into the behavioural, cognitive, physiological, and evolutionary underpinnings. The seasonal variability of bird populations presents an intriguing phenomenon for avid observers to discern their origins, migratory routes, and return patterns. Among the remarkable migrations executed by several species of fish, animals, and insects, birds exemplify the highest degree of mobility among all living forms on Earth. This paper gives reasons for all Bird migration strategies with a view toward the preservation of Bird ecosystems and assurance of Environmental sustainability.

Contrasting seasonal responses to wind in migrating songbirds on a globally important flyway.

During spring migration, nocturnal migrants attempt to minimize their travel time to reach their breeding grounds early. However, how they behave and respond to unfavourable conditions during their springtime travels is much less understood. In this study, we reveal the effects of atmospheric factors on nocturnal bird migration under adverse conditions during spring and autumn, based on one of the most detailed bird migration studies globally, using radar data from 13 deployments over a period of seven years (2014-2020) in the Levant region. Using ERA5 reanalysis data, we found that migratory birds maintain similar ground speeds in both autumn and spring migrations, but during spring, when encountering unfavourable winds, they put more effort into maintaining their travel speed by increasing self-powered airspeed by 18%. Moreover, we report for the first time that spring migrants showed less selectivity to wind conditions and migrated even under unfavourable headwind and crosswind conditions. Interestingly, we discovered that temperature was the most important weather parameter, such that warm weather substantially increased migration intensities in both seasons. Our results enhance our understanding of bird migration over the Levant region, one of the world's largest and most important migration flyways, and the factors controlling it. This information is essential for predicting bird migration, which-especially under the ongoing anthropogenic changes-is of high importance.

Evaluating the potential of bioacoustics in avian migration research by citizen science and weather radar observations.

The study of nocturnal bird migration brings observational challenges because of reduced visibility and observability of birds at night. Remote sensing tools, especially radars, have long been the preferred choice of scientists to study nocturnal migrations. A major downside of these remote sensing tools is the lack of species-level information. With technological advances in recent decades and with improved accessibility and affordability of acoustic tools, sound recordings have steeply increased in popularity. In Europe, there is no exhaustive qualitative and quantitative evaluation of the content of such acoustic databases and therefore the value for migration science and migration-related applications, such as bird collision hazard assessments, is mostly unknown. In the present work we compared migration schedules estimated from citizen science data with quantitative temporal occurrence of species in four years of acoustic recordings. Furthermore, we contrasted acoustic recordings with citizen science observations and weather radar data from one spring and one autumn season to assess the qualitative and quantitative yield of acoustic recordings for migration-related research and applications. Migration intensity estimated from weather radar data correlated best at low levels with acoustic records including all species in spring while in autumn passerine species showed stronger correlation than the entire species composition. Our findings identify a minor number of species whose call records may be eligible for applications derived from acoustics. Especially the highly vocal species Song thrush and Redwing showed relatively good correlations with radar and citizen science migration schedules. Most long-distance passerine migrants and many other migrants were not captured by acoustics and an estimated seasonal average of about 50% of nocturnally migrating passerine populations remained undetected. Overall, the ability of acoustic records to act as a proxy of overall migration dynamics is highly dependent on the migration period and species involved.

Mites Living in the Nests of the White Stork and Black Stork in Microhabitats of the Forest Environment and Agrocenoses.

The White Stork (Ciconia ciconia) and the Black Stork (Ciconia nigra) are well-known model organisms for the study of bird migration, as well as the selectivity of nesting sites and the choice of living environment. The former breeds mainly in open areas, while the latter inhabits forest areas. The acarofauna, and in particular Oribatida, inhabiting the nests of these species, has not been thoroughly explored so far. Therefore, we analyzed the material collected from 70 White Stork nests and 34 Black Stork nests in Poland, between Poznań and Rawicz, and in Kampinos National Park. Our research has increased the faunal and ecological knowledge of the mite fauna inhabiting the nests of large migratory bird species. Oribatida constituted 5-12% of the total mites identified in the nests of White and Black Storks. Their average number was several times higher in the Black Stork nests (80.2 individuals in 500 cm3). Also, the species diversity of moss mites was greater in the Black Stork nests (47 species). In total, the nests of the two stork species were inhabited by 62 moss mite species, with only 22 recorded in both the White and the Black Storks' nests. The most numerous species included Ramusella clavipectinata, R. fasciata, Oppiella subpectinata, Acrogalumna longipluma, and Scheloribates laevigatus. In addition, we found that juvenile oribatid mites accounted for 0.6% of all the mites in the White Stork nests, with tritonymphs having the largest share, while juveniles in the Black Stork nests comprised 1.4%, of which larvae and protonymphs had the largest share. Our research shows that the nests of large migratory birds provide living space for many mite species. In addition, we noted the potential importance of White and Black Stork nests for mite dispersion and the evolution of interspecies interactions.

Automatic detection of migrating soaring bird flocks using weather radars by deep learning

Abstract The use of weather radars to detect and distinguish between different biological patterns greatly improves our understanding of aeroecology and its consequences for our lives. Importantly, it allows us to quantify passerine bird migration at different scales. Yet, no algorithm to detect soaring bird flocks in weather radar is available, precluding our ability to study this type of migration over large spatial scales. We developed the first automatic algorithm for detecting the migration of flocks of soaring birds, an important bio‐flow phenomenon involving many millions of birds that travel across large spatial extents, with implications for risk of bird‐aircraft collisions. The algorithm was developed with a deep learning network for semantic segmentation using U‐Net architecture. We tested several models with different weather radar products and with image sequences for flock movement identification. The best model includes the radial velocity product and a sequence of two previous images. It identifies 93% of soaring bird flocks that were tagged by a human on the radar image, with a false discovery of less than 20%. Large birds such as those detected by the algorithm pose a serious risk for flight safety of civilian and military transportation and therefore the application of this algorithm can substantially reduce bird‐strikes, leading to reduced financial losses and threats to human lives. In addition, it can help overcome one of the main challenges in the study of bird migration by automatically and continuously detecting flocks of large birds over wide spatial scales without the need to equip the birds with tracking devices, unravelling the abundance, timing, spatial flyways, seasonal trends and influences of environmental conditions on the migration of bird flocks.

盐城沿海海堤林带柳莺属(Phylloscopus)鸟类秋季迁徙规律

江苏盐城沿海具有广阔的平原与湿地滩涂，但缺少自然林地。经过多年的防风林建设，沿海海堤逐渐形成了特有的、南北走向的条带林生境，为迁徙鸟类提供了通道和停歇地，是研究鸟类迁徙规律的理想地点。柳莺属鸟类个体小，野外种类识别难，其迁徙规律缺乏深入研究。分别于2018年和2019年两个秋季，采用雾网法对盐城沿海海堤林带柳莺属鸟类的迁徙规律进行研究。结果表明：两个秋季共捕获柳莺属鸟类8种608只，其中极北柳莺（Phylloscopus borealis）、冕柳莺（P. coronatus）、淡脚柳莺（P. tenellipes）和黄眉柳莺（P. inornatus）的捕获数量分别为245只、131只、107只和94只，占捕获总数量的95%，是秋季迁徙期的优势种。对优势种柳莺日捕获率进行比较：2019年极北柳莺的日捕获率显著高于淡脚柳莺和黄眉柳莺（U test，P<0.05）。对捕获数量随时间变化进行分析，4种柳莺都以集中在短时间内快速通过的迁徙策略穿越盐城沿海海堤林带，符合秋季小型雀形目鸟类迁徙采取时间最小化假说。不同种类的柳莺在通过盐城沿海海堤林带的时间顺序上存在显著差异（K-W test，P<0.05），2018年和2019年均以黄眉柳莺通过最晚。随着时间的推移，四种柳莺的脂肪度都逐渐下降。繁殖地纬度的差异可能是导致4种柳莺通过盐城沿海海堤林带时间差异的原因。盐城沿海海堤林带为柳莺属等雀形目小型鸟类的迁徙提供了非常理想的迁徙通道，应当加强海堤林带在鸟类迁徙和保护中的作用研究。;There are vast plains and wetlands in the coastal area of Yancheng City, Jiangsu Province, China, but there lack natural forest lands. After several decades of construction, the Yancheng coastal seawall forests have formed a very unique habitat with north-south direction narrow forest belts. These forest belts have been served as important migrating channels or stopover sites for long-distance migratory birds. Therefore, an ideal place for the study of bird migration has been provided in this site. However, due to the small body size of warblers, it is difficult to identify them in the field which limits our understanding of their migration patterns. Here, by using mist-nets, we collected eight dominant migratory warbler species in autumn in 2018 and 2019, and studied the temporal rhythm of their migration. In total, 608 warblers belonging to 8 species were captured by using mist-nets in autumn in 2018 and 2019, including 245, 131, 107 and 94 individuals for Phylloscopus borealis, P. coronatus, P. tenellipes and P. inornatus, respectively. The total captured number of these four species accounted for 95% of all the captured warblers, indicating that they were the dominant migratory warbler species in this study site in autumn. The daily captured number of P. borealis in 2019 was significantly higher than those of P. tenellipes and P. inornatus (U test, P<0.05). Based on the changing of captured number with time, all these four dominant warblers tended to adopt the migration strategy that pass through the study site rapidly in a concentrated time. This is consistent with the hypothesis that small passerines usually choose time minimizing strategies to get to the winter sites as soon as possible in autumn. There was a significant difference in the temporal rhythm of the four warbler species in both years (K-W test, P<0.05). The warbler P. inornatus was the last one that passed through the study site both in 2018 and 2019. The fat scores of all the four warbler species significantly decreased with the migration time. We consider that the differences in the temporal rhythm of the four warbler species might attribute to the differences in the geographic locations of their breeding sites. In conclusion, the Yancheng seawall forest belt provided an appropriate migration channel for small passerines such as the warblers. More studies should be conducted to explore the important roles of the Yancheng seawall forest belts for bird migration and conservation in the future.

A tale of two seasons: The link between seasonal migration and climatic niches in passerine birds.

The question of whether migratory birds track a specific climatic niche by seasonal movements has important implications for understanding the evolution of migration, the factors affecting species' distributions, and the responses of migrants to climate change. Despite much research, previous studies of bird migration have produced mixed results. However, whether migrants track climate is only one half of the question, the other being why residents remain in the same geographic range year‐round. We provide a literature overview and test the hypothesis of seasonal niche tracking by evaluating seasonal climatic niche overlap across 437 migratory and resident species from eight clades of passerine birds. Seasonal climatic niches were based on a new global dataset of breeding and nonbreeding ranges. Overlap between climatic niches was quantified using ordination methods. We compared niche overlap of migratory species to two null expectations, (a) a scenario in which they do not migrate and (b) in comparison with the overlap experienced by closely related resident species, while controlling for breeding location and range size. Partly in accordance with the hypothesis of niche tracking, we found that the overlap of breeding versus nonbreeding climatic conditions in migratory species was greater than the overlap they would experience if they did not migrate. However, this was only true for migrants breeding outside the tropics and only relative to the overlap species would experience if they stayed in the breeding range year‐round. In contrast to the hypothesis of niche tracking, migratory species experienced lower seasonal climatic niche overlap than resident species, with significant differences between tropical and nontropical species. Our study suggests that in seasonal nontropical environments migration away from the breeding range may serve to avoid seasonally harsh climate; however, different factors may drive seasonal movements in the climatically more stable tropical regions.

Revealing the potential of a huge citizen-science platform to study bird migration

ABSTRACTThe currently best-known ornithological citizen-science platform is Cornell’s eBird, which provides crucial information for bird migration studies. Considering the solid validity of eBird data, and after a validation process, we comparatively explored the data available in the Brazilian-wide platform WikiAves for bird migration studies. We selected five migratory and four resident species as models, controlling for likely sampling biases derived from efforts by the platform collaborators. If data in WikiAves were adequate for migration studies, we respectively expected, after a between-platform comparison, similar yearlong seasonal and non-seasonal occurrence records of all migratory and resident species. Data analysis supported our expectations: eBird and WikiAves data showed consistent temporal occurrence patterns for all evaluated species. Therefore, we selected another six model-species showing literature inconsistency on their migratory behaviour, demonstrating for the first time the potential of a Brazilian citizen-science database – WikiAves – in unveiling geographically seasonal occurrence patterns of the understudied migratory bird species in Brazil. Our study highlights the general public relevance on reducing knowledge gaps about bird migration in Brazil, revealing a feasible strategy to overcome some current logistic barriers that preclude advances in South American bird migration studies, a currently underexplored research area, especially by Brazilian researchers.

Inferring the Wintering Distribution of the Mediterranean Populations of European Storm-Petrels Hydrobates pelagicus melitensis from Stable Isotope Analysis and Observational Field Data

Bird migration studies have been given added impetus recently thanks to the miniaturisation of tracking devices. However, tracking methodologies have remained impractical for the smallest pelagic species and so important gaps in knowledge still exist. In the case of the European Storm-petrel Hydrobates pelagicus, while Atlantic populations are thought to overwinter along the south-western African coast, the winter quarters of Mediterranean birds remain more enigmatic. We performed stable isotope analysis (SIA) of C and N on P1, S8 and P10 feathers from 33 adult birds captured in three Atlantic colonies and 156 adult birds in seven western Mediterranean colonies to infer their wintering areas. In addition, we collated all observational field data, both from peer-reviewed publications and the wider literature, to complement our inferences from SIA. Within the Atlantic, isotopic profiles of feathers moulted at the breeding grounds (P1) differed between birds captured at northern Atlantic and Canary Islands colonies, but were similar for feathers moulted in winter quarters (S8 and P10), indicating low migratory connectivity. Isotopic values of feathers from western Mediterranean birds differed from those of Atlantic birds and showed Mediterranean values for all feathers, indicating that the former overwinter in Mediterranean waters. Variance in the isotopic values was greater in winter than in breeding season feathers, suggesting that birds disperse over larger areas in winter. Isotopic values of feathers moulted during the non-breeding period could match a post-breeding movement towards the southern and eastern Mediterranean. This inference matches the distribution of the few winter reports, which are mainly concentrated in the south-central Mediterranean, mostly in the Tunisian Platform. Our results suggest that this region is the principal wintering area of Mediterranean Storm-petrels.—Martinez, C., Roscales, J.L., Sanz-Aguilar, A. & Gonzalez-Solis, J. (2019). Inferring the wintering distribution of the Mediterranean populations of European Storm-petrels Hydrobates pelagicus melitensis from stable isotope analysis and observational field data. Ardeola, 66: 13-32.

Carrying a logger reduces escape flight speed in a passerine bird, but relative logger mass may be a misleading measure of this flight performance detriment

Abstract The recent boost in bird migration studies following the development of various tracking devices raised awareness of how detrimental attaching devices can be for animals. Such effects can occur during migration, but also immediately post‐release if the device impairs escape flight performance and, consequently, the bird's ability to evade predators. In this study, we investigated the effect of carrying a device on the escape flight speed and aerodynamic force production in a migratory passerine. We recorded upward‐directed escape flights of 15 male blackcaps. Each individual was tested without a tag, and when equipped with three different leg‐loop dummy tags with masses representing around 3%, 5%, and 7% of their body mass. The experiment was designed such that all individuals passed through all treatments in a randomized order. We found that two factors affected flight speed in roughly equal amounts: first, tagged escape flights had lower flight speeds compared to the control flights, irrespective of tag mass. Second, we found an effect of the total mass, that is, the sum of the masses of the individual bird and of the tag, with heavier birds being slower. In contrast, flight speed was not correlated with relative tag mass in percentage of body mass, the metric commonly used in ethical guidelines for tag attachment. Aerodynamic flight force production also depended on total mass, with heavier birds producing higher forces. But these flight forces did not differ between flights with or without a tag. We conclude that, when tagging birds, it is misleading to choose heavy individuals for tagging in order to minimize the tag mass as a percentage of body mass. This is particularly relevant in species for which body mass is not necessarily related to size, like migratory birds that accumulate large fat reserves. The lower escape speed in “tagged” flights could not be explained by differences in net flight force production, because these did not differ between flights with and without a tag. This suggests that the tag also affected pre‐flight take‐off dynamics, possibly due to a leg harness‐induced reduction in leg push‐off performance.

Sir Richard Graham and the marking of ducks at Netherby, Cumberland, 1908–1933 – an early bird-ringing project

ABSTRACTTo increase the variety of game available on his estate at Netherby, near Carlisle, Sir Richard Graham began in 1890 to develop extensive facilities for the captive breeding of wild ducks. Large numbers of birds were involved, 8000–10 000 Mallard Anas platyrhynchos being reared annually in the peak years around 1900, and thousands of Eurasian Teal A. crecca a decade or so later. One of the innovations that Graham and his keeper W. Bell made was to fit some of the birds with metal rings, creating one of the first British projects to take advantage of the then-novel technique of bird ringing. A little over 2000 birds, mainly Eurasian Teal but including also some Gadwall Mareca strepera, Eurasian Wigeon M. penelope, Mallard, Northern Pintail A. acuta, and Common Snipe Gallinago gallinago were marked between 1908 and 1933. Initially some privately produced rings showing only the year of ringing were used (c1000 birds): between 1930 and 1932, privately produced but serially numbered rings were used (c300 birds); and at other times rings issued by the British Birds Marking Scheme were used (c800 birds). In total, 103 ring recoveries from birds marked in these various ways have been identified. Although most were from birds that had been part of Graham’s captive-breeding programme, their movements do not appear to differ markedly from those of fully wild birds. The purpose of marking the birds, the effectiveness of the various types of rings used and the overall contribution of the project to early studies of bird migration are briefly discussed.

Patterns of nocturnal bird migration in southern Mexico

The Isthmus of Tehuantepec is the narrowest landmass between the Gulf of Mexico and the Pacific Ocean. It is known as an important stopover site and migration corridor for Nearctic-Neotropical migratory birds. We characterized nocturnal bird migration along the Pacific side of the isthmus with marine radar, and identified species with diurnal point counts during 5 fall seasons (2009–2013) at operational and proposed wind farms. We found significant differences in migratory traffic rates, flight directions, and flight altitudes among years and sites, but we also found patterns of similarity including flight directions heading to the southeast each season; migratory traffic rates peaking 3–4h after sunset and decreasing thereafter; flight altitudes increasing throughout the night; seasonal mean flight altitudes fluctuating between ∼520 and ∼720m above ground level (m agl); and <7% of detected targets flying below 100m agl. Our data suggest that migratory activity initiates around mid-September and peaks in mid-October. We identified 58 bird species of nocturnal migrants. Studies of nocturnal bird migration are important for understanding potential impacts from wind farms.

Using Theoretical Flight Speeds to Discriminate Birds from Insects in Radar Studies

Abstract. Marine radar is a tool widely used in the study of bird migration, but in most cases it cannot identify detected objects to species. For this reason airspeed is used as one of the main criteria to separate birdlike from insectlike targets, but this criterion has not been tested outside the temperate regions where it was developed. We used a theoretical approach for calculating minimum-power speeds (Vmp) and maximum-range speeds (Vmr) of birds and insects to estimate an interval of airspeeds from which an appropriate value of the criterion can be selected and to propose a criterion based on flight speed for the Isthmus of Tehuantepec in southern Mexico. This approach, with data from 36 species of insects and 60 of passerines either known to occur or similar to species occurring in southern Mexico, found that although Vmp of insects and birds overlaps at 5.5 m sec-1, birds generally fly faster than insects. After combining our results with data from the literature, we conclude that the best airspe...

Seasonal differences in behavior patterns of the migratory white-throated sparrow

Avian migration and associated changes in behavior patterns occur on a seasonal basis and are regulated by both circadian and circannual clocks. It is well known that seasonally migrating birds must alter the temporal partitioning of behaviors in order to successfully complete nocturnal migration, although the precise changes in allocation have not previously been examined. Because of the difficulties related to the study of bird migration in the wild, many studies regarding the physiology of migration have been performed in captivity, where nocturnal migratory restlessness is readily observable at the appropriate times of the year. Even so, quantifying the amount and timing of daily behavioral rhythms in migrating and non-migrating individuals has not previously been performed. We used video recordings of a common nocturnal migrant, the white-throated sparrow (Zonotrichia albicollis), to generate a basic ethogram and to chart the timing and frequency of occurrence of each behavior in order to compare migrant individuals with non-migrating birds. Our study suggests that the specific allocation of behaviors are altered during migration and that these changes might contribute to the development of the “migratory syndrome”.

An Overview of Bird Migration Studies in Egypt

ABSTRACT Ibrahim W.A.L. 2011. An overview of bird migration studies in Egypt. Ring 33, 1-2: 55-75. This is an overview of ornithological studies carried out in Egypt since the beginning of XXth century till the present time made on the basis of several more or less general publications. Geographical location and climate descriptions give the background information about the area. The literature overview stresses especially problems connected with the migration of passerines, but wider avifaunistic background is discussed as well. Special attention is paid to the passerines’ strategy of migration through the Mediterranean Sea and Sahara Desert, its direction and timing, as well as to the factors affecting passerines migration and bird ringing in Egypt. In conclusion, it is stressed that the studies on bird migration were done sporadically, from time to time and from one place to another, and there is a dramatic lack of permanent ringing / bird migration study field stations, despite the fact that some suitable and promising localities have been found, in which the studies have been carried out since 2001 by the SE European Bird Migration Network in cooperation with some protected areas managements.

The Development of a Genome Wide SNP Set for the Barnacle Goose Branta leucopsis

Migratory birds are of particular interest for population genetics because of the high connectivity between habitats and populations. A high degree of connectivity requires using many genetic markers to achieve the required statistical power, and a genome wide SNP set can fit this purpose. Here we present the development of a genome wide SNP set for the Barnacle Goose Branta leucopsis, a model species for the study of bird migration. We used the genome of a different waterfowl species, Mallard Anas platyrhynchos, as a reference to align Barnacle Goose second generation sequence reads from an RRL library and detected 2188 SNPs genome wide. Furthermore, we used chimeric flanking sequences, merged from both Mallard and Barnacle Goose DNA sequence information, to create primers for validation by genotyping. Validation with a 384 SNP genotyping set resulted in 374 (97%) successfully typed SNPs in the assay, of which 358 (96%) were polymorphic. Additionally, we validated our SNPs on relatively old (30 years) museum samples, which resulted in a success rate of at least 80%. This shows that museum samples could be used in standard SNP genotyping assays. Our study also shows that the genome of a related species can be used as reference to detect genome wide SNPs in birds, because genomes of birds are highly conserved. This is illustrated by the use of chimeric flanking sequences, which showed that the incorporation of flanking nucleotides from Mallard into Barnacle Goose sequences lead to equal genotyping performance when compared to flanking sequences solely composed of Barnacle Goose sequence.

“An outstanding man among Scottish ornithologists”: Surgeon Rear-Admiral John Hutton Stenhouse (1865–1931)

A biographical sketch of John Hutton Stenhouse (1865–1931) is provided. This focuses on his contributions to ornithology in Scotland and to Scottish ornithology, most notably through his long association with the Royal Scottish Museum. His involvements with bird migration studies on Fair Isle and his influence on the subsequent development of a permanent bird observatory on the island are discussed

Optimal site matching of wind turbine generator: Case study of the Gulf of Suez region in Egypt

During the last few years, Egypt has emerged as the leader of wind power in the Middle East and Africa. In the Gulf of Suez region, a continuously expanding large-scale grid-connected wind farm is available at Zafarana site. The Gulf of EL-Zayt site in the Gulf of Suez region is now under extensive studies related to wind power projects such as feasibility and bird migration studies. Therefore, the Gulf of Suez region is considered in this paper for optimal site matching of wind turbine generator (WTG). This paper treats the problem of site matching of WTG through improved formulation of the capacity factor. Such factor is estimated based on Weibull PDF and an accurate model for the WTG output-power-curve. Ornithological, martial, and other limitations placed on WTG hub heights in the Gulf of Suez region in Egypt are taken into account. In addition, a MATLAB based program is created to implement the presented technique of optimal site matching of WTG. Based on turbine-performance-index (TPI) maximization, optimal output-power-curve and optimal commercial WTG are determined for each candidate site in the Gulf of Suez region. Long-term performance measurements at Zafarana wind farms in comparison with the results are used to validate the presented technique and the optimality of the results.

Integrating concepts and technologies to advance the study of bird migration

Recent technological innovation has opened new avenues in migration research – for instance, by allowing individual migratory animals to be followed over great distances and long periods of time, as well as by recording physiological information. Here, we focus on how technology – specifically applied to bird migration – has advanced our knowledge of migratory connectivity, and the behavior, demography, ecology, and physiology of migrants. Anticipating the invention of new and smaller tracking devices, in addition to the ways that technologies may be combined to measure and record the behavior of migratory animals, we also summarize major conceptual questions that can only be addressed once innovative, cutting‐edge instrumentation becomes available.

Any change in the Methodology of field studies on bird Migration? A comparison of methods used in 1994-2003 and a Quarter Century earlier

Any change in the Methodology of field studies on bird Migration? A comparison of methods used in 1994-2003 and a Quarter Century earlier The holistic approach to the study of bird migration observed in the past decades and the huge advancement in technology should be seen in the numbers and types of methods used in field studies for this phenomenon. To check this assumption, we compared field methods used in the studies on bird migration published in international journals in 1994-2003 (N = 570 papers) and in 1967-1976 (N = 394 papers). We noted an increase in the mean number of methods per a single paper (from 1.49 in the former of these decades to 1.98 in the latter) and a change in the frequency of each method. In recent years, methods such as satellite telemetry, DNA or isotope proportions analyses have been developed. An increase in the mean number of methods as well as changes of the most frequently used methods were more apparent in journals indexed on the ISI Master Journal List in 2003 than in other current journals, where the methods were often found to be similar to those applied a quarter century earlier, which surprised us.