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The effects of recent climate change on the phenology of avian breeding and migration, geographical range shifts, and decreasing migration distances are well documented. Only a few studies have focused on the long-term influence of these changes on the body condition of migrants, which is important as it is likely to affect the fitness of the whole population. Eurasian blackcaps have adapted their migratory behaviour to changing ecological factors. These changes seem to favour the species and its migratory populations have increased over the last decades in Europe. In the present study, we analysed the body condition index of juvenile blackcaps at their stop-over site in the southern Baltic region during autumn migration from 1967 to 2006. This index was distinctly higher since the 1990s than in the middle of the 1960s, when the number of migrating blackcaps was at least twofold lower. Moreover, there was a reduction in recapture rates of blackcaps from 14% to 6% during these periods which may imply that warblers were staying for a shorter time at the stop-over site as their body condition was higher. We hypothesized that higher berry crop availability resulted in the higher condition of migrating blackcaps. Body condition index also reflecting fuel load in migrants was higher in long-distance blackcaps compared to the short-distance ones. As the former are time-minimizing migrants, their higher body condition/fuel load may allow them to migrate faster to wintering grounds in sub-Saharan Africa. [ABSTRACT FROM AUTHOR]

The effects of recent climate change on the phenology of avian breeding and migration, geographical range shifts, and decreasing migration distances are well documented. Only a few studies have focused on the long-term influence of these changes on the body condition of migrants, which is important as it is likely to affect the fitness of the whole population. Eurasian blackcaps have adapted their migratory behaviour to changing ecological factors. These changes seem to favour the species and its migratory populations have increased over the last decades in Europe. In the present study, we analysed the body condition index of juvenile blackcaps at their stop-over site in the southern Baltic region during autumn migration from 1967 to 2006. This index was distinctly higher since the 1990s than in the middle of the 1960s, when the number of migrating blackcaps was at least twofold lower. Moreover, there was a reduction in recapture rates of blackcaps from 14% to 6% during these periods which may imply that warblers were staying for a shorter time at the stop-over site as their body condition was higher. We hypothesized that higher berry crop availability resulted in the higher condition of migrating blackcaps. Body condition index also reflecting fuel load in migrants was higher in long-distance blackcaps compared to the short-distance ones. As the former are time-minimizing migrants, their higher body condition/fuel load may allow them to migrate faster to wintering grounds in sub-Saharan Africa.

Abstract Even after decades of research, the migration of songbirds still holds numerous secrets. Distinct stopover and routing behavior of diurnally and nocturnally migrating songbirds has been stated in the 1960s, but empirical confirmation is yet lacking widely. We studied the behavior of individual diurnally migrating dunnocks and nocturnally migrating blackcaps by means of large‐scale automated radio‐telemetry. Birds were radio‐tagged during their stopover at the German North Sea coast. Our data indicate longer initial stopover duration in the diurnally migrating dunnocks, opposing the hypothesis of nocturnal migrants needing more time to recover due to their longer migratory flights. Nonetheless, dunnocks stopped over more often along their tracks as when compared to the nocturnally migrating blackcaps. Behavior en route did not differ as clearly between species challenging the general view of contrasting routings of diurnal and nocturnal migrants with regard to landscape and open water. Our results imply additional factors of relevance other than differences in species or daily migration timing per se. We discuss and highlight the need of detailed and individual based data to better understand stopover and routing behavior of songbirds in the environmental context.

Presentation of a general pattern of migration is very difficult in the case of small passerines, especially nocturnal migrants, as the few accepted methods are inefficient here. It is difficult to follow migration visually (by visual field observations or moon watching). Classic ringing must be extremely intensive due to low or very low recovery rates, especially in Africa, Eastern Europe and Asia, which additionally rule out any reasonable estimation of the intensity of migration towards different destinations. Radar studies tell us nothing about the migration of individual species. Even the most modern methods, such as geolocation and radio tracking, are of very limited use for population studies. For these reasons, in most cases our knowledge in this area is fragmentary and insufficient for a satisfactory description of migration. In many cases only the breeding areas have been faunistically described in detail, while the winter-quarters and areas where the species is observed during migration are frequently described with less precision. The introduction of an effective method for studying local headings of migrants, using 'orientation cages', has made it possible to study the migration patterns of small passerine nocturnal migrants. The presented work is a case study on the migration pattern of the Blackcap, using data from orientation tests collected in autumn as part of the work of SEEN (SE European Bird Migration Network), consisting of 5,392 tests performed at 28 ringing sites in Central/Eastern Europe and the Middle East. The paper continues the discussion of the problem of applying the method to presentation of migration patterns in a geographically wide territory (Busse 2018, 2019, 2020). The hypothesis put forth by Busse (2019) that the arrival/departure heading axes are generally linear is accurate to within about one 10° sector was confirmed earlier. Here it was confirmed at the level of local patterns for the study sites. In general, the average deviation from the straight line is below 1°. However, there is some geographical variation, and this problem could be discussed when many more results of this kind become available for a few more species. Eight headings/streams of migrants are defined for the Blackcap within the area. Southward and south-eastern streams dominate in most of the study area. However, a very special, nearly longitudinal heading was found in southern Europe and the Middle East, which requires further study. Comparison of the patterns obtained from three different procedures strongly suggests that the general picture of Blackcap migration in Central/Eastern Europe and the Middle East is clear and coherent. Some variation in migration stream parameters (linearity and reversed heading share) suggests that further research in this direction should be conducted using data from other species. [ABSTRACT FROM AUTHOR]

Abstract Many bird species are sexually monomorphic and cannot be sexed based on phenotypic traits. Rapid sex determination is often a necessary component of avian studies focusing on behavior, ecology, evolution, and conservation. While PCR‐based methods are the most common technique for molecularly sexing birds in the laboratory, a simpler, faster, and cheaper method has emerged, which can be used in the laboratory, but importantly also in the field. Herein, we used loop‐mediated isothermal amplification (LAMP) for rapid sex determination of blood samples from juvenile European blackcaps, Sylvia atricapilla, sampled in the wild. We designed LAMP primers unique to S. atricapilla based on the sex chromosome‐specific gene, chromo‐helicase‐DNA‐binding protein (CHD), optimized the primers for laboratory and field application, and then used them to test a subset of wild‐caught juvenile blackcaps of unknown gender at the time of capture. Sex determination results were fast and accurate. The advantages of this technique are that it allows researchers to identify the sex of individual birds within hours of sampling and eliminates the need for direct access to a laboratory if implemented at a remote field site. This work adds to the increasing list of available LAMP primers for different bird species and is a new addition within the Passeriformes order.

The blackcap Sylvia atricapilla shows a complex migratory pattern and is a suitable species for the studies of morphological migratory syndrome, including adaptations of wing shape to different migratory performance. Obligate migrants of this species that breed in northern, central, and Eastern Europe differ by migration distance and some cover shorter distance to the wintering grounds in the southern part of Europe/North Africa or the British Isles, although others migrate to sub-Saharan Africa. Based on ˃40 years of ringing data on blackcaps captured during autumn migration in the Southern Baltic region, we studied age- and sex-related correlations in wing pointedness and wing length of obligate blackcap migrants to understand the differences in migratory behavior of this species. Even though the recoveries of blackcaps were scarce, we reported some evidence that individuals which differ in migration distance differed also in wing length. We found that wing pointedness significantly increased with an increasing wing length of migrating birds, and adults had longer and more pointed wings than juvenile birds. This indicates stronger antipredator adaptation in juvenile blackcaps than selection on flight efficiency, which is particularly important during migration. Moreover, we documented more pronounced differences in wing length between adult and juvenile males and females. Such differences in wing length may enhance a faster speed of adult male blackcaps along the spring migration route and may be adaptive when taking into account climatic effects, which favor earlier arrival from migration to the breeding grounds. [ABSTRACT FROM AUTHOR]

Busse P. 2020. An analysis of orientation cage field data - a case study of headings of the Blackcap, Sylvia atricapilla, at the Bukowo/Kopañ ringing site in Poland. Ring 42: 51-74. One of the most effective methods of studying the migratory patterns of nocturnal passerine migrants is the use of orientation cages as a supplementary procedure at ringing sites. The most comprehensive studies using orientation cages (Busse's Flat Orientation Cage) were conducted within the SEEN network (SE European Bird Migration Network), with more than 43,000 tests performed at more than 40 ringing sites in autumn. A number of papers were published based on these data, presenting an overall pattern of passerine migration over SE Europe-Middle East-NE Africa. For more detailed analyses, it was first necessary to solve some methodical problems within case studies. The current work presents details for discussion based on data from 1338 tests of Blackcaps performed during the years 1995-2010 at a single ringing station, Bukowo/Kopañ, located on the Polish Baltic coast. The birds were tested according to the standard methodology of the SEEN network (Busse 2000). The problems investigated were (1) the repeatability of heading patterns obtained in different years, (2) the linearity of the estimated arrival and departure headings, and (3) quantitative aspects of the results in the description of the heading pattern when migratory groups are found. It was determined that (1) yearly heading patterns were generally coherent and could be analysed as uniform case data; (2-1) the hypothesis that the arrival/departure heading axes are generally linear is accurate to within about one 10° sector, at least in the case of the Blackcap. This is coherent with impressions from other known data sets, but does not mean that the rule always applies to all species at every location on the migration route. In the future, this problem should be studied on a more detailed scale. It was further established that (2-2) estimating arrival and departure headings makes it possible to define migratory groups (populations) passing the study site. The direct heading estimation procedure seems to be more sensitive in identifying migratory groups than the calculation procedure. Moreover, (3-1) the calculation procedure makes it possible to estimate some quantitative properties of headings of migratory groups and define some interesting, though preliminary, number patterns of local migratory patterns; (3-2) the number relations between birds demonstrating the arrival and departure headings of the migratory group seem to be an interesting parameter for study on the distance of migration of groups within a species and, possibly, between species. This is another interesting problem that cage tests could be used to solve in the future. Finally, (3-3) knowledge about trends of individual populations passing the defined site becomes accessible only using analysis of data from orientation cages. The estimated quantitative indices discussed above could be helpful in presenting the general migratory pattern of the species on a geographical scale. [ABSTRACT FROM AUTHOR]

Even after decades of research, the migration of songbirds still holds numerous secrets. Distinct stopover and routing behavior of diurnally and nocturnally migrating songbirds has been stated in the 1960s, but empirical confirmation is yet lacking widely. We studied the behavior of individual diurnally migrating dunnocks and nocturnally migrating blackcaps by means of large‐scale automated radio‐telemetry. Birds were radio‐tagged during their stopover at the German North Sea coast. Our data indicate longer initial stopover duration in the diurnally migrating dunnocks, opposing the hypothesis of nocturnal migrants needing more time to recover due to their longer migratory flights. Nonetheless, dunnocks stopped over more often along their tracks as when compared to the nocturnally migrating blackcaps. Behavior en route did not differ as clearly between species challenging the general view of contrasting routings of diurnal and nocturnal migrants with regard to landscape and open water. Our results imply additional factors of relevance other than differences in species or daily migration timing per se. We discuss and highlight the need of detailed and individual based data to better understand stopover and routing behavior of songbirds in the environmental context. [ABSTRACT FROM AUTHOR]

Many bird species are sexually monomorphic and cannot be sexed based on phenotypic traits. Rapid sex determination is often a necessary component of avian studies focusing on behavior, ecology, evolution, and conservation. While PCR‐based methods are the most common technique for molecularly sexing birds in the laboratory, a simpler, faster, and cheaper method has emerged, which can be used in the laboratory, but importantly also in the field. Herein, we used loop‐mediated isothermal amplification (LAMP) for rapid sex determination of blood samples from juvenile European blackcaps, Sylvia atricapilla, sampled in the wild. We designed LAMP primers unique to S. atricapilla based on the sex chromosome‐specific gene, chromo‐helicase‐DNA‐binding protein (CHD), optimized the primers for laboratory and field application, and then used them to test a subset of wild‐caught juvenile blackcaps of unknown gender at the time of capture. Sex determination results were fast and accurate. The advantages of this technique are that it allows researchers to identify the sex of individual birds within hours of sampling and eliminates the need for direct access to a laboratory if implemented at a remote field site. This work adds to the increasing list of available LAMP primers for different bird species and is a new addition within the Passeriformes order. [ABSTRACT FROM AUTHOR]

This is the first report of species adulteration in a collection of commercially available bokbunja (Rubus coreanus Miquel) products (n = 17) sold in Korea and the US (all originated from Korea). Twelve samples contained R. occidentalis L. fruit; the two species are clearly distinguishable by their anthocyanin profiles. Seven of 17 products were labeled in English to contain R. coreanus fruit; five of these samples contained R. occidentalis and two contained black carrot anthocyanins. The ten other products described contents as “bokbunja.” For two of the 17 products, species classification could not be made due to low anthocyanin present, while three of the 17 were adulterated with black carrot anthocyanins and contained no fruit anthocyanins. Anthocyanins ranged from 0.8 to 56.9 mg/100 mL, a 71-fold difference, for all samples. We are hopeful that this research will aid bokbunja growers, processors, and researchers in creating, reporting, and marketing accurately labeled improved foods.

In the U.S., there has been a recent surge in Korean black raspberry products available and in the number of reports about this species appearing in the scientific literature. Despite this, the majority of products sold and the work carried out has been on Rubus occidentalis L., not R. coreanus Miquel. The importance of accurate recognition of all starting material is multiplied for research downstream, including genetics/genomics, plant breeding, phenolic identification, food processing improvements and pharmacokinetic investigations. An overview of distinguishing characteristics separating R. coreanus from R. occidentalis will be presented. Research conducted on correctly identified fruit will also be summarized to aid future studies that might showcase the unique qualities that bokbunja can offer.

Black raspberry (Rubus occidentalis L.) has long been recognized as a rich source of anthocyanins. Despite renewed interest in this crop for its potential health benefits, the range of variation in anthocyanin content and other phenolic compounds has not been well examined. Here we present anthocyanin concentration and profiles, as well as total phenolics, in the fruit of 26 black raspberry seedling populations (190 samples over two growing seasons) derived from cultivated and wild parents. There was more than a twofold difference in total anthocyanin concentration between the lowest and highest pigmented populations (ranging from 244.8 to 541.3 mg 100 mL−1). The relative amounts of the two major anthocyanins (cyanidin-3-rutinoside and cyanidin-3-xylosylrutinoside) in black raspberry fruit were significantly different. The range of total phenolics found was much lower (206.7–330.4 mg 100 mL−1). This information will provide a valuable baseline for researchers interested in studying the health effects of these compounds, product developers in the nutraceutical market, and breeders interested in developing new cultivars with improved fruit chemistry traits.

Fuel accumulation, mainly as fatty acids, is one of the main characteristics of migratory birds. Studying to what extent each population or species manages fuel load and how it varies along routes of migration or between seasons (autumn and spring migrations) is crucial to our understanding of bird migration strategies. Our aim here was to analyse whether migratory blackcaps Sylvia atricapilla passing through northern Iberia differ in their mean fuel loads, rate of fuel accumulation and 'potential' flight ranges between migration seasons. Blackcaps were mist netted for 4 h-periods beginning at dawn from 16 September to 15 November 2003–2005, and from 1 March to 30 April 2004–2006 in a European Atlantic hedgerow at Loza, northern Iberia. Both fuel load and fuel deposition rate (this latter assessed with difference in body mass of within-season recaptured individuals) were higher in autumn than in spring. Possible hypotheses explaining these results could be seasonal-associated variations in food availability (likely lower during spring than during autumn), the fact that a fraction of the migrants captured in spring could breed close to the study area and different selective pressures for breeding and wintering [Current Zoology 55 (6): 401–410, 2009].

Recent climate change has a major impact on the sizes and distribution of bird populations, the phenology of their breeding/migration and migratory behaviour (migration distance, migration strategy). We documented changes in the numbers of juvenile Blackcaps migrating in autumn through the S Baltic that were paralleled by changes in wing length of captured individuals during a 43-year study period (1967-2009). We suggest that the observed trends may indicate changing population composition of migrating birds. In the Blackcap, wing length distinguishes among different populations and increases with increasing migration distance of a given population. Available published data show that long-distance and short-distance Blackcaps pass the study region. Hence, we assumed that shorter-winged birds are short-distance migrants wintering in the southern Europe, and that longer-winged individuals are long-distance migrants wintering in the sub-Saharan region. It seems that in 1967-1980 most Blackcap populations declined, but, as wing length slightly increased, the rate of this decline has been higher in the shorter-winged/short-distance Blackcaps. Over the subsequent 24 years alongside with rapidly growing numbers of birds, we noted a remarkable decrease in wing length. This indicates a pronounced increase in the number of short-distance individuals compared to long-distance migrants. Both groups may benefit from improved conditions at their breeding grounds, but the shorter migration route and favourable conditions at wintering sites north of Sahara could favour short-distance migrants over the longer distance and longer-winged Blackcaps. [ABSTRACT FROM AUTHOR]

In songbirds, territorial songs are key regulators of sexual selection and are learned from conspecifics. The cultural transmission of songs leads to divergence in song characteristics within populations, which can ultimately lead to speciation. Many songbirds also migrate, and individual differences in migratory behaviours can influence population genetic structure and local song differentiation. Blackcaps, Sylvia atricapilla, exhibit versatile territorial songs and show diversity in migration behaviours. They therefore comprise a good model for investigating the relationships between migratory patterns, song variation, and genetic diversity. We studied a migratory population (two groups near Paris) and a sedentary population (three groups in Corsica). All of the birds were ringed and blood sampled to investigate genetic relatedness using 17 microsatellite loci. A detailed song analysis showed that this species has a complex repertoire (> 100 syllables), which required the development of a semi-supervised method to classify different categories of syllables and compare sequences of syllables. Our analysis showed no genetic structuring among populations: individuals belonging to the same group were not genetically closer than those from different groups. However, we found a strong wingsize difference between sedentary and migratory populations. We also showed that geographical variations in songs rely at least on both syllable and sequence content. Unexpectedly, despite a higher turnover of individuals, migratory groups share as many syllables and sequences as sedentary groups, which raises interesting issues on song learning and the maintenance of dialects in migratory birds. [ABSTRACT FROM AUTHOR]

A lack of genetic diversity in cultivated black raspberry ( Rubus occidentalis L.) germplasm has been widely recognized as a major factor limiting progress towards breeding improved cultivars. Despite this, little effort has been made since the early twentieth century to systematically collect and evaluate wild black raspberry for germplasm improvement. In recent years, there has been renewed interest in black raspberry breeding to replace existing cultivars that lack durability and disease resistance. We planted seedlings from 109 wild black raspberry populations, representing 24 US states and two Canadian provinces, in the field in replicated trial plots in Corvallis, Oregon (USA), to evaluate their performance. These populations showed wide variation in morphology, architecture, fruiting season, vigor, and apparent field tolerance to Verticillium wilt. For nearly every trait examined, wild black raspberry germplasm exhibited a range of variation beyond existing cultivars, and showed great potential for use in future breeding. While most populations were fairly uniform phenotypically, segregation for fruit gloss and possible tolerance to Verticillium wilt was noted in a few, indicating the possibility of simple inheritance of these traits. A few populations with unusual morphology, such as spinelessness or flower abnormalities, were identified, as were populations that flowered on first year canes and produced fall fruit. Populations from the southern edge of the range appear to be particularly well adapted to western Oregon, with vigorous upright growth, strong canes, and some with a low incidence of Verticillium wilt. This germplasm will be of great value to breeders interested in developing improved black raspberry cultivars. [ABSTRACT FROM AUTHOR]

Human activities are causing rapid environmental change at a global scale. Urbanization is responsible for some of the most extreme human-altered habitats and is a known driver of evolutionary change, but evidence and understanding of these processes is limited. Here, we investigate the potential underlying mechanisms contributing to the contemporary evolution of migration behaviour in the Eurasian blackcap ( Sylvia atricapilla). Blackcaps from central Europe have been wintering in urban areas of Britain with increasing frequency over the past 60 years, rather than migrating south to the Mediterranean. It has been hypothesized that the popularization of providing supplementary foods for wild birds within Britain may have influenced this marked migratory change, but quantifying the selective forces shaping evolutionary changes remains challenging. Using a long-term national scale data set, we examine both the spatial distribution and interannual variation in blackcap wintering behaviour in Britain in relation to supplementary food availability and local climate. Over a 12-year period, we show that blackcaps are becoming increasingly associated with the provision of supplementary foods in British gardens, and that the reliability of bird food supplies is influencing their winter distribution at a national scale. In addition, local climatic temperatures and broader scale weather variation are also important determinants of blackcap wintering patterns once they arrive in Britain. Based on our findings, we conclude that a synergistic effect of increased availability of feeding resources, in the form of garden bird food, coupled with climatic amelioration, has enabled a successful new wintering population to become established in Britain. As global biodiversity is threatened by human-induced environmental change, this study presents new and timely evidence of the role human activities can play in shaping evolutionary trajectories. [ABSTRACT FROM AUTHOR]

Bird songs are complex manifold acoustic signals serving two main functions: mate attraction and territorial defense. The way information is encoded in the song often reflects adaptation to proximate and ultimate constraints. Male blackcaps, Sylvia atricapilla , display versatile songs with two parts, a warble and a whistle, whose functions remain unclear. We showed that the two parts of songs differ in terms of intensity, frequency and temporal parameters. They also contain totally different sets of syllables. Furthermore, the warble is versatile whereas the whistle part shows syllable sharing between individuals leaving closeby. Altogether, the results of our analysis suggest that the two parts encode different information potentially directed to different audiences. In order to test the potential function of these two parts, we performed playback experiments by broadcasting entire songs and each part separately. Warble and whistle alone are sufficient to trigger male responses and males sing both parts in responses to all stimuli, showing that both parts of the song are used in male–male competition. It is suggested that the segregation of information in the blackcap song could be related to public versus private communication, used in both intra- and intersexual contexts, rather than directed to male versus female audiences only. [ABSTRACT FROM AUTHOR]

Bird song is a sexually selected signal that serves two main functions, attracting a mate and deterring rivals. Different signal parameters may be important in advertising to females compared to advertising to rival males. Species solve the problem of this dual function in a variety of ways, one of which may be to have separate parts of song directed at male and female receivers. The blackcap song has two distinct parts, a complex warble, assumed to be directed at female receivers, followed by a louder and more stereotyped whistle putatively directed at males. We simulated territorial intrusions by broadcasting blackcap song in territories. Comparing songs sung prior, with those produced in response to playback, showed that the proportion of the whistle component of songs increased, but not the warble. This study thus provides empirical evidence that the whistle component of the blackcap song plays a prominent role in male-male competition. The warble component of the blackcap song may be directed at females, but this requires further testing. [ABSTRACT FROM AUTHOR]

This is the first report of species adulteration in a collection of commercially available bokbunja ( Rubus coreanus Miquel) products (n = 17) sold in Korea and the US (all originated from Korea). Twelve samples contained R. occidentalis L. fruit; the two species are clearly distinguishable by their anthocyanin profiles. Seven of 17 products were labeled in English to contain R. coreanus fruit; five of these samples contained R. occidentalis and two contained black carrot anthocyanins. The ten other products described contents as “bokbunja.” For two of the 17 products, species classification could not be made due to low anthocyanin present, while three of the 17 were adulterated with black carrot anthocyanins and contained no fruit anthocyanins. Anthocyanins ranged from 0.8 to 56.9 mg/100 mL, a 71-fold difference, for all samples. We are hopeful that this research will aid bokbunja growers, processors, and researchers in creating, reporting, and marketing accurately labeled improved foods. [ABSTRACT FROM AUTHOR]

Melanin is the most common pigment in animal integuments including bird plumage. It has been shown that several trace elements may play roles in the production and signaling function of melanin-colored plumage. We investigated coloration and content of various metal elements in the rectrices of two insectivorous passerines, Common Redstarts (Phoenicurus phoenicurus) and Blackcaps (Sylvia atricapilla), which have eumelanin- and pheomelanin-based coloration, respectively. We hypothesized that 1) the two species would differ in concentrations of metals important in melanin synthesis (Ca, Fe, Cu, Zn), 2) differences in metal concentration levels would be related to feather coloration. Our study confirmed the first prediction and provides the first evidence that selected elements may play a greater role in pheomelanin than in eumelanin synthesis. Concentrations of three elements considered as important in melanin synthesis (Ca, Fe, Zn) were 52% to 93% higher in rusty colored Common Redstart feathers compared to the dark gray Blackcap feathers. However, element concentrations were not correlated with feather coloration or sex in either species. Our study suggests that, of the two melanin forms, pheomelanin synthesis may bear higher costs associated with the acquisition of specific elements or limited elements may create trade-offs between ornamentation and other physiological functions. Our findings warrant further investigations designed to better understand the roles of macro- and microelements in the synthesis of both forms of melanin. [ABSTRACT FROM AUTHOR]

Abstract: In Israel, a well-known avian migratory bottleneck, there is a temporal and geophysical divide in the flyways. The migration at Eilat, at the southern tip of Israel, is disjunct from the flyway in central and northern Israel. In order to elucidate the differences between the two flyways, we compared the data collected simultaneously at the Kfar Ruppin ringing station in northern Israel, and in the IBRCE Bird Sanctuary in Eilat at the southern tip of Israel. We chose the three most common species that are typical long distance, trans-Saharan, passerine migrants: Blackcap (Sylvia atricapilla), Lesser Whitethroat (Sylvia curruca) and Reed Warbler (Acrocephalus scirpaceus). At both ringing stations, the number of migrants recorded in spring was considerably greater than in autumn for all three species. Individuals from all species analysed in both passage seasons at Kfar Ruppin had longer wings than in Eilat, and in spring all three species were heavier in Kfar Ruppin. Our study is the first to show that there are biometric differences within Israel and stress the need to study the eastern migratory flyway of the Western Palaearctic in order to fully understand the intercontinental movements of the EurAsian migratory passerine populations. [Copyright &y& Elsevier]

Introduction A remarkable aspect of bird migration is its nocturnality, particularly common in Passeriformes. The switch in activity from purely diurnal to also nocturnal is evident even in caged birds that during migratory periods develop an intense nocturnal restlessness, termed Zugunruhe. The mechanisms that control this major change in activity are mostly unknown. Previous work with Sylvia warblers suggested an involvement of melatonin, a hormone associated with day-night cycles in most vertebrates. In a recent study we found no effects of melatonin administration on Zugunruhe during spring migration. However, previous studies indicated that the response to melatonin manipulation could differ between spring and autumn migration, which are in fact separate life history stages. Here we tested whether a non-invasive treatment with melatonin can alter Zugunruhe in wild garden warblers S. borin and blackcaps S. atricapilla subject to temporary captivity at an autumnal stopover site. Food availability in the cage (yes/no) was added as a second factor because previous work showed that it enhanced Zugunruhe. Results The melatonin treatment significantly decreased the amount of Zugunruhe, while the availability of food only tended to increase the amount of Zugunruhe. Fuel deposits also had a strong effect on the amount of nocturnal activity: lean birds with a fat score of 1 showed significantly less Zugunruhe than fatter birds. The change in body mass during the time spent in the recording cage depended on food availability, but not on any of the other factors. Conclusions This study shows that the migratory programme of two Sylvia warblers can be manipulated by administration of exogenous melatonin and confirms that this hormone is involved in the control of migratory behaviour. To our knowledge, this is one of the first demonstrations that the autumn migratory programme can be altered by hormonal manipulation in migrating birds. The comparison with a similar study carried out with the same modalities during spring migration suggests that there are seasonal differences in the sensitivity of the migratory programme to hormonal factors. In birds breeding in the northern hemisphere, the importance of a timely arrival to the breeding sites could explain why the control of the migratory programme is more rigid in spring. [ABSTRACT FROM AUTHOR]

Breeding progress in black raspberry ( Rubus occidentalis L.) has been limited by a lack of genetic diversity in elite germplasm. Black raspberry cultivars have been noted for showing very few phenotypic differences and seedlings from crosses between cultivars for a lack of segregation for important traits. Despite these challenges, little molecular work has been done to explore genetic diversity and relationships in wild and cultivated black raspberry germplasm. Microsatellite, or simple sequence repeat (SSR), markers are highly polymorphic codominant markers useful for studying genetic diversity, population genetics, genetic fingerprinting and other applications. We examined genetic diversity in 148 wild and cultivated black raspberry accessions using 21 polymorphic SSR markers. Black raspberry cultivars clustered tightly and showed higher than expected heterozygosity while that of wild accessions was low. Relationships between wild black raspberry accessions were poorly resolved and regional clusters were mostly absent from our analysis. Our results indicated that wild black raspberry germplasm is a relatively untapped resource available for future breeding. [ABSTRACT FROM AUTHOR]

During migratory flight, the mass of the gastrointestinal tract (GIT) and its associated organs in small birds decreases in size by as much as 40%, compared with the preflight condition because of the catabolism of protein. At stopover sites, birds need 2-3days to rebuild their GIT so that they can restore body mass and fat reserves to continue migration. The source of protein used to rebuild the GIT may be exogenous (from food ingested) or endogenous (reallocated from other organs) or both. Because the relative contribution of these sources to rebuild the GIT of migratory birds Is not yet known, we mimicked in-flight fasting and then re-feeding in two groups of blackcaps {Sylvia athcapilla), a Palearctic migratory passerine. The birds were fed a diet containing either 3% or 20% protein to simulate different refueling scenarios. During re-feeding, birds received known doses of 15N-L-leucine before we measured the isotope concentrations in GIT and associated digestive organs and in loco mot ory muscles. We then quantified the extent to which blackcaps rebuilt their GIT with endogenous and/or dietary protein while refeeding after a fast. Our results indicate that blackcaps fed the low-protein diet incorporated less exogenous nitrogen into their tissues than birds fed the 20% protein diet. They also allocated relatively more exogenous protein to the GIT than to pectoral muscle than those birds re-fed with the high-protein diet. However, this compensation was not sufficient for birds eating the low-protein diet to rebuild their intestine at the same rate as the birds re-fed the high-protein diet. We concluded that blackcaps must choose stopover sites at which they can maximize protein intake to minimize the time it takes to rebuild their GIT and, thus, resume migration as soon as possible. [ABSTRACT FROM AUTHOR]

The article discusses a study which investigated the effect of nest site location on the breeding success and nest site selection of blackcaps Sylvia Atricacpilla in Poland. The researchers observed nest predation as the only cause of reproductive failure. Analysis revealed the significant effect of the abundance of bramble within a territory as well as nest concealment on the nest success in blackcaps. Nest height and the abundance of elder and hornbeam brushwood showed insignificant effect on nest success. A significant number of blackcaps also preferred bramble as nest sites over elder or hornbeam brushwood.

The distribution area and the timing of migration of many bird species have recently changed, presumably due to climatic factors. In our study, we estimated the effect of climate change on migration phenology and biometrics of two sister Sylvia species: the medium-distance migrant Blackcap ( Sylvia atricapilla) and the long-distance migrant Garden Warbler ( Sylvia borin). We used the data of 52,440 Blackcaps and 6,943 Garden Warblers caught and ringed at the Ócsa Bird Ringing Station (47°15′N, 19°15′E) in Hungary between 1984 and 2008. The age and in case of Blackcaps the sex groups were handled separately. The timing of the spring migration of Garden Warblers shifted earlier, whereas it did not change in Blackcaps during the study period. We presume-in accordance with other observations concerning Blackcaps in West-Europe-that it probably has changed earlier than the 1980s. The timing of autumn migration shifted about 2 weeks later in all age and sex groups of Blackcaps. We found significant correlation in the timing of autumn migration of sex groups, the sign of the differences between the timing of males and females changed. Juvenile Garden Warblers shifted their autumn migration 13 days later, but adults did not. Mean body mass decreased while mean wing length increased suggesting a change in the composition of the trans-migrant population. We hypothesise that due to climate change the breeding range of these species expanded northwards, producing an increased ratio of long-winged northern individuals in the trans-migrant populations. [ABSTRACT FROM AUTHOR]

Abstract: Black raspberry (Rubus occidentalis L.) has long been recognized as a rich source of anthocyanins. Despite renewed interest in this crop for its potential health benefits, the range of variation in anthocyanin content and other phenolic compounds has not been well examined. Here we present anthocyanin concentration and profiles, as well as total phenolics, in the fruit of 26 black raspberry seedling populations (190 samples over two growing seasons) derived from cultivated and wild parents. There was more than a twofold difference in total anthocyanin concentration between the lowest and highest pigmented populations (ranging from 244.8 to 541.3mg100mL−1). The relative amounts of the two major anthocyanins (cyanidin-3-rutinoside and cyanidin-3-xylosylrutinoside) in black raspberry fruit were significantly different. The range of total phenolics found was much lower (206.7–330.4mg100mL−1). This information will provide a valuable baseline for researchers interested in studying the health effects of these compounds, product developers in the nutraceutical market, and breeders interested in developing new cultivars with improved fruit chemistry traits. [ABSTRACT FROM AUTHOR]

The article presents a suggestion by researchers that migratory birds prioritize the development of the primary feathers on their wings to the detriment of their tail feathers, which are considered of secondary importance. They arrived at this conclusion by comparing the plumage of Blackcaps, which are migratory, against sedentary ones. They found that the quality of their wing feathers were superior to their feather tracts. They believe this is due to their need to conserve the energy required to sustain them during their long flights.

Abstract: We studied the stopover ecology of Blackcaps in Eilat, Israel, at the northern edge of the Saharan desert crossing. We investigated the Blackcaps with regard to differential migration by sex or age class in spring and autumn, and the stopover site in spring and autumn were compared. Using data from 1984 to 2003, we studied stopover length and fat deposition patterns differentiated by sex. In spring, Blackcap females remained in Eilat significantly longer than males. This suggests that males maintain a migration strategy of time-minimization, while females place more importance on energy-maximization. This difference is probably due to upcoming reproductive roles at the breeding grounds. [Copyright &y& Elsevier]

Passerine birds migrating long distances arrive at stopover sites to refuel having lost as much as 50%of their initial body mass (mb) including significant losses to digestive organs that may serve as a reservoir of protein catabolised for fuel during flight. Birds newly arrived at a stopover show slow or no mb gain during the initial 2-3 days of a stopover, which suggests that energy assimilation may be limited by reduced digestive organs. Measurements of migrants and captive birds subjected to simulated migratory fasts have shown reductions in intestine mass, morphological changes to the mucosal epithelium, and reductions in food intake and assimilation rate upon initial refeeding. We found that blackcaps (Sylvia atricapilla, Linnaeus) newly arrived at a migratory stopover after crossing the Sahara and Sinai deserts had significantly increased paracellular nutrient absorption (non-carrier mediated uptake occurring across tight junctions between enterocytes) that may provide partial compensation for reduced digestive capacity resulting from changes to intestinal tissues. Indeed, newly arrived birds also had a slightly reduced capacity for absorption of a glucose analogue (3-O-methyl-D-glucose) transported simultaneously by both carrier-mediated and non-mediated mechanisms. Increased paracellular absorption coupled with extended digesta retention time may thus allow migratory blackcaps to maintain high digestive efficiency during initial stages of refuelling while digestive organs are rebuilt. [ABSTRACT FROM AUTHOR]

The article discusses the impact of sampling frequency (SF) in determining differential timing of migration. Previous reports indicate that migration schedules were affected by age in autumn when adults migrate earlier and by sex in spring when males start earlier. The Blackcaps Sylvia atricapilla songbird was chosen due to the available numbers and the ease of determining age and sex. In the autumn of 2005 and spring of 2006, Blackcaps were marked in a 48-hectare area in Loza, Spain, that is used as breeding ground by local birds and as a stopover site by foreign birds. Results show that differential timing between sexes or age classes was detectable at certain levels of SF but not at lower SF. In spring, differential timing between age classes only became significant with daily sampling.

The article presents a study which examines the Blackcaps in a Mediterranean forest located at the southern edge of the Iberian Peninsula. Researchers evaluated intra-individual constancy in the length, mass, and growth rate of tail feathers between complete moults of 13 free-living individual Blackcaps Sylvia atricapillia. Researchers found out that plumage is regularly replaced over the lifetime of birds and variable conditions experienced during plumage development can affect feather growth rate. They concluded that the time to produce similar feathers increases with age.

Hosts of brood parasites use a variety of cues relating to eggshell appearance of parasitic eggs, which facilitate their recognition and rejection. It has been documented that host visual perception of different colours including UV wavelengths plays an Important role in this respect. In the study reported here, we aimed to test whether artificial reduction of the UV wavelengths reflected from parasitic eggshell affects rejection behaviour in the blackcap Sylvia atricapilla. To achieve this goal, we experimentally manipulated, with UV, part of spectra reflected from conspecific eggs and reduced it into the range of 320-350 nm. We used an ultraviolet light blocker, which did not influence the reflectance shape of other spectrum parts. We also used a group of experimental eggs coated in Vaseline, which had no effect on the spectral shape in the UV or visible ranges of the light spectrum. Additionally, we used a third experimental group of unmanipulated eggs as a control. The experimental eggs coated In the UV blocker were rejected at a higher rate than those coated in the Vaseline. Moreover, a binary logistic regression revealed that an artificial reduction of the UV wavelengths reflected from the parasitic egg significantly affected the probability of being rejected by the hosts. To our knowledge, this is the first experimental study to reveal that manipulation with UV wavelengths affects the recognition of parasitic eggs, indicating that the UV part of the spectrum has an Important role In host recognition behaviour. [ABSTRACT FROM AUTHOR]

Variation in appearance of parasitic and host eggs is an essential trait in the coevolutionary struggle between a brood parasite and its host. Here we examined the role of colour characteristics in the egg recognition in blackcaps, Sylvia atricapilla, assessed by (1) human vision and (2) spectrophotometry, including UV wavelengths. Since colour and spotting pattern within eggs are often highly variable, we also assessed three different parts of blackcap eggshell separately. We investigated the possibility that a lower intraclutch variation in the parasitized clutch would positively affect egg recognition. In addition, we predicted that egg rejection would depend on contrast between host and parasitic eggs. However, we found that neither intraclutch variation nor mimicry if assessed by humans had significant effect on host rejection. Multivariate analyses of spectrophotometric data revealed, however, that the likelihood of egg rejection significantly increased with decreasing intraclutch variation in blue chroma. Furthermore, probability of egg rejection significantly increased with decreasing contrast between parasitic and host eggs in UV wavelengths and with decreasing brightness of host eggs at the blunt egg pole. Accepted foreign eggs were significantly darker at the blunt pole than acceptors'' own eggs. The paradox that rejected eggs had lower contrast could be explained by the fact that the contrast in UV spectra is associated with brightness of the blunt egg part. Our data suggest that colour characteristics of the blunt egg part may play a major role in the recognition of parasitic eggs in the blackcaps. [Copyright &y& Elsevier]

Blackcaps Sylvia atricapilla reject artificial cuckoo eggs, and their eggs vary little in appearance within clutches, whereas among clutches eggs vary considerably. Low variation within clutches facilitates discrimination of parasitic eggs, whereas high variation among clutches makes it harder for the cuckoo to mimic the eggs of a certain host species. These traits have most probably evolved as counteradaptations against brood parasitism by the common cuckoo Cuculus canorus, even though blackcaps are not regularly parasitised today. In this study, we investigated how fine-tuned the rejection of parasitic eggs is in this species by introducing three types of eggs into their nests: a real non-mimetic egg the approximate size of a cuckoo egg, an artificial mimetic egg the size of a cuckoo egg and a real conspecific egg. As the rejection frequency of both mimetic and non-mimetic artificial cuckoo eggs has been shown to be high in previous studies, the variation in rejection behaviour between individuals is low, indicating that most individuals within the population are able to reject parasitic eggs. Thus, we predict that (1) the intraclutch variation in egg appearance should be generally low in all individuals, and that (2) regarding conspecific eggs, rejection decisions should be highly dependent on the degree of mimicry between parasitic and host eggs. We found support for these predictions, which indicates that due to their highly sophisticated countermeasures against brood parasitism, blackcaps can probably be regarded as current winners of the arms race with the common cuckoo. Furthermore, the high and consistent rejection frequency of cuckoo eggs found throughout Europe for this species supports the spatial habitat structure hypothesis, which claims that woodland-nesting species breeding near trees, like blackcaps, presumably experienced a high level of parasitism throughout their range in the past and, therefore, their rejection behaviour, once evolved, spread rapidly to all populations. [ABSTRACT FROM AUTHOR]

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Fluctuating asymmetry is considered an indirect measure of phenotypic quality and can directly impose high costs in terms of aerodynamics in flying birds. The accuracy of orientation during migration in small passerines is relevant for survival and reproduction, but patterns of individual variation in preferred directions have received little attention. I tested the hypothesis that symmetrical individuals are able to more accurately orient in the correct direction than asymmetrical individuals. Wing, tail and tarsus asymmetry were measured in blackcaps (Sylvia atricapilla), redstarts (Phoenicurus phoenicurus) and robins (Erithacus rubecula), and the birds were tested for orientation in Emlen funnels, at two stopover sites in N Europe. I then matched individuals for test date, species, sex and age, and assigned them to either of two groups: symmetrical or asymmetrical. The groups were not different in any of the orientation parameters. The lack of effect of asymmetry on orientation may imply that: (i) choices of different direction reflected different, but equally effective migratory strategies; (ii) symmetrical birds could afford longer stopovers while asymmetrical ones be less motivated to migrate; (iii) differences in orientation behaviour would have reflected different quality only under novel or anomalous conditions or (iv) fluctuating asymmetry is not a useful measure of quality. [ABSTRACT FROM PUBLISHER]

• WNV seropositivity discovered in birds in Cyprus. • Majority of seropositive samples are from migrant Sylvia atricapilla. • Migrant birds implicated for WNV outbreak in humans. • Illegal trapping of S. atricapilla may increase risk of infection. West Nile Virus (WNV) 1 1 West Nile Virus, WNV is an emerging pathogen in Cyprus, with the first human case of infection reported in 2016, and another documented in 2018. A cluster of cases in humans was then reported in 2019. However, little is known regarding which avian species might bring WNV to Cyprus. Here, we investigated seroprevalence of WNV antibodies in migratory and resident birds, captured across Cyprus to assess to what extent human populations might be exposed to WNV. We used Enzyme-Linked Immunosorbent Assay (ELISA) 2 2 Enzyme-Linked Immunosorbent Assay, ELISA to test for the presence of WNV antibodies in 836 avian blood samples of 44 species captured between 2015 and 2020. A seropositivity rate of 1.3 % was found. The majority of seropositive wild birds belonged to the migratory species Sylvia atricapilla , a common and widespread migrant, implying a high risk of WNV being introduced throughout Cyprus. [ABSTRACT FROM AUTHOR]