rss_2.0The Ring FeedSciendo RSS Feed for The Ring Ring Feed European Autumn Migration Pattern of the Blackcap, – From Faunistic Observations to a Basic Analysis of Orientation Cage Field Data<abstract> <title style='display:none'>Abstract</title> <p>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).</p> <p>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.</p> </abstract>ARTICLEtrue European Autumn Migration Pattern of the Garden Warbler, – A Basic Analysis of Orientation Cage Field Data<abstract> <title style='display:none'>Abstract</title> <p>The introduction of an effective method for studying the local headings of migrants using ‘orientation cages’ has made it possible to study the migration patterns of small passerine nocturnal migrants. Numerous papers have been published on varied samples of local data collected using this method. A rough generalization was presented at the 2019 Meeting of the European Ornithologists Union and subsequently published in <italic>The Ring</italic>. Case studies on data collected for the Blackcap have already been published, and further studies on other species were suggested. The presented work is the next study of this kind, on the migration pattern of the Garden Warbler, using data from orientation tests collected in autumn as part of the work of the SEEN (SE European Bird Migration Network). The data comprises 2,593 tests performed at 31 ringing sites in Central/Eastern Europe and the Middle East. The paper continues the discussion of application of the method to present migration patterns in a geographically wide territory. The general data evaluation methods in this work are exactly as described in the earlier papers. The paper discusses azimuths of arrival and departure tracks at every ringing site, their linearity, number relations between departing and arriving headings, and the general pattern of migration streams followed by different groups of migrants.</p> <p>The hypothesis put forth earlier, stating that the arrival/departure heading axes shown in studies using orientation cages are situated linearly, is once again confirmed and can be used as a general assumption in this type of study. The average deviations are very small and are negligible for drawing general migration patterns. In some cases, however, there were deviations caused by the geographic location of the study site. This problem should be discussed in more detail when more species data become available. Nine migration streams are defined in the study area, which are presented, for simplicity, using different names and colours on maps. Southward and south-eastward streams are dominant and distributed similarly to the streams of the Blackcap. The most pronounced is a stream shown in yellow (<italic>YELLOW stream</italic>), which is directed from the wide area of central and eastern Europe to the Arabian Peninsula. The <italic>BLACK</italic> and <italic>NAVY</italic> streams are the most intriguing (running nearly longitudinally) and require a great deal of attention in further analyses of migration in the Mediterranean. Two styles of presentation of the species migration pattern are discussed, of which the location style of presentation seems to be more precise. The simpler presentation style that shows only general heading axes could be used to compare the general patterns of different species.</p> </abstract>ARTICLEtrue Captures and Biometrics of Goldcrests at a Western Hungarian Stopover Site<abstract> <title style='display:none'>Abstract</title> <p>Annual captures and biometric parameters of the Goldcrest (<italic>Regulus regulus</italic>) were studied at Tömörd, western Hungary. We used records of 4,284 individuals trapped and ringed between August and November within the study period (1998–2020). The Goldcrest was determined to be a regular partial migrant species with highly intensive migration in 2000, 2001, 2008, 2014 and 2019. The catching results showed very high number fluctuations at Tömörd, but the smoothed curves were distinctly wave-like in all age and sex classes. There were significant positive correlations between annual captures of age and sex classes. The average proportion of immature Goldcrests was 90%, the average proportion of male individuals was 63% and both proportions were stable between 1998 and 2020. There were similar decreasing trends in the average annual wing length and body mass of males and females from 1998 to 2020. This may indicate that the migration strategies of females may be modified by global climate change.</p> </abstract>ARTICLEtrue General Pattern of Seasonal Dynamics of The Autumn Migration of The Wood Pigeon in Italy<abstract><title style='display:none'>Abstract</title><p>Cavina E., Bucchi R. and Busse P. 2018. <italic>The general pattern of seasonal dynamics of the autumn migration of the Wood Pigeon Columba palumbus in Italy</italic>. Ring 40: 3-18.</p><p>Given the scarcity of studies on the migration of the Wood Pigeon through Italy, the first systematic observations by a network of hunters, as citizen researchers, can be presented as a starting point for more in-depth analyses. Observations from the years 1998-2006 are analysed and presented in a generalized form. During this period more than 100 observation sites, covering most of Italy, were active for about 40 days every autumn. Migration over Italy was described in terms of the timing and intensity of migration. Special attention was directed to the long-term number dynamics and seasonal dynamics of the passage. The most intensive migration was observed within northern Italy, while lower intensity is visible more to the south of the peninsula. Following tendencies in numbers of observed migrants within the ten years of the study, we can find positive tendencies in most of the northern provinces, while three negative trends are visible in central Italy. The study of the seasonal pattern, in terms of the number dynamics of the passage and the frequency of pronounced peak days, strongly suggests that there are five or six waves of pigeons passing through Italy in different parts of the autumn that are quite stable between years. Every year the time of the passage includes a few peak days of migration.</p></abstract>ARTICLEtrue of Pre-Nuptial Migration of the Song Thrush in Calabria (Southern Italy)<abstract><title style='display:none'>Abstract</title><p>Muscianese E., Martino G., Sgro P., Scebba S. and Sorrenti M. 2018. <italic>Timing of pre-nuptial migration of the Song Thrush Turdus philomelos in Calabria (southern Italy)</italic>. Ring 40: 19-30.</p><p>The European Commission has established that pre-nuptial migration of the Song Thrush <italic>Turdus philomelos</italic> in Italy begins in the second decade (10-day period) of January. This three-year study was carried out at two localities in the Calabria region of southern Italy from 2012 to 2014, with 3-4 ringing sessions every decade from mid-January to the end of March. In total, 447 birds were captured. Based on catching dynamics and changes in fat load and body mass, we documented that the species’ northward migration took place in mainly March, with early movements in February. As no migratory activity was detected before the second decade of February, the dates of the hunting season in this area can be re-considered.</p></abstract>ARTICLEtrue of Local Heading Patterns of Nocturnal Migrants using Orientation Cages<abstract><title style='display:none'>Abstract</title><p>Busse P. 2018. <italic>Estimation of local heading patterns of nocturnal Migrants using orientation cages</italic>. Ring 40: 31-58</p><p>The main aim of this paper is to compare the results of two data evaluation procedures used for presenting the data from the orientation cage field tests. Both procedures accept multimodality of the data and multimodality of the headings of an individual bird as well as migrating population. The goal is to reach acceptable level of migration patterns presentation in biological sense, taking under consideration a flexibility of the real movements, depending on specific weather and landscape parameters. Such knowledge is absolutely necessary for estimating migration bottle-necks and the long-term studies on influence of the climate changes on migration patterns. The material used for the comparison of the procedures was collected in years 2001-2007 by the team of the Bulgarian Ringing Station Kalimok (44°00’N, 26°26’E) within the frame of the SEEN (SE European Bird Migration Network) activity and kindly shared for evaluation. The data were obtained using the standard SEEN methods, with the standard Busse’s cage working procedure of the field tests. The material contains data on four species of nocturnal migrants living in different habitats: the Great Reed Warbler, <italic>Acrocephalus arundinaceus</italic> (ACR.ARU), the Sedge Warbler, <italic>A. schoenobaenus</italic> (ACR.ENO), the Willow Warbler, <italic>Phylloscopus trochilus</italic> (PHY.LUS) and the Whitethroat, <italic>Sylvia communis</italic> (SYL.COM). There are confirmed earlier conclusions that so called „classic” unimodal procedure is not applicable to the orientation cage data resulted from any field procedure. There are available two evaluation procedures that base on the same general assumptions: multimodality of distributions that reflects combination of several unimodal partial distributions, that can be described both using sophisticated Bayesian „<italic>Calculation</italic>” method and much simpler „<italic>Estimation</italic>” procedure. Results of both procedures are enough close to each other that they can be used for describing local and general heading patterns of migration of the nocturnal migratory movements studied using orientation cages.</p></abstract>ARTICLEtrue of Multiple Adjoining Habitats on Avifaunal Diversity in an Agriculture-Based Wetland Adjacent to the Hooghly River, West Bengal, India<abstract><title style='display:none'>Abstract</title><p>Sau M., Chakraborty M., Das R. and Mukherjee S. 2018. <italic>Effect of multiple adjoining habitats on avifaunal diversity in an agriculture based-wetland adjacent to the Hooghly River, West Bengal, India</italic>. Ring 40: 59-92.</p><p>This study was conducted on four plots having a cluster of different combinations of forest, wetland, and agricultural land, as well as a single marshland habitat near the river Hooghly. We obtained 17,817 counts for 150 species in 32 days of year-round sampling. The wetland-agricultural land associated with forest had the highest species diversity (132 species, Shannon <italic>̄H</italic><italic>–</italic> 1.63), heterogeneity (Shannon <italic>J’ –</italic> 0.773), and number of unique species (33 species), and the lowest dominance (Simpson Index 1/<italic>D –</italic> 39.35), in contrast with the marsh, which had the lowest diversity (41 species, Shannon <italic>̄H –</italic> 1.39), highest homogeneity (Shannon <italic>J’</italic> – 0.863), and a lack of uniqueness. The plot with secondary forest patches between an agricultural field and human settlements showed the highest species dominance (Simpsons Diversity 1/<italic>D</italic> – 17.465). Species rarity ranged from 68.2% to 77.6% within the area under study. There were 25 species common to all plots, which formed six distinct groups based on their abundance. Carnivores were found to be the dominant foraging guild throughout the habitats. Thirty-two per cent of the species are migratory, with the families <italic>Scolopacidae</italic> and <italic>Motacillidae</italic> predominating. The Jaccard and Sorensen indices reveal the greatest species similarity between the wetlandpisciculture plot and the marshland. These indices together with the hierarchical cluster analysis indicate the uniqueness of the plot of open forest habitat adjoining the wetland, which offers the best living conditions for migratory species. Our study concludes that when a wetland is surrounded by agriculture rather than fisheries, avifaunal diversity increases, whereas forest-associated wetland-farmland maximizes species richness with minimum dominance and hence imparts greater stability to the overall community structure.</p></abstract>ARTICLEtrue Role of a Water Canal and Secondary Forest for Migrants<abstract><title style='display:none'>Abstract</title><p>Forests have an important role during migration. They act as ecological corridors and provide resting and feeding places for birds. In our study, we sought to determine whether migratory birds prefer secondary forest or canal vegetation during migration. The study was carried out in Southeast Hungary, in an oleaster forest and in a canal. We used 12 mist nets and the ringing method. The study period lasted from August to October 2016–2018, covering approximately the entire migration period. According to our results, the canal has a significant effect on the species assemblage, as it functions as a migration corridor during migration, most likely not only for diurnal migrants, but for nocturnal migrants as well. Our results showed that the presence of both woody and berry plants had some influence on the species composition. Interestingly, the presence of berries had a positive effect on the presence of insectivorous birds.</p></abstract>ARTICLEtrue Structure of Migratory Waterbirds at Two Important Wintering Sites in a Sub-Himalayan Forest Tract in West Bengal, India<abstract><title style='display:none'>Abstract</title><p>The waterbird community structures of two sub-Himalayan wetlands (Nararthali and Rasomati) situated in forested areas were compared during the wintering period. These wetlands had similar geophysical features but were subject to different conservation efforts. Sixty species of waterbirds, including four globally threatened species, were recorded during the study. Nararthali was found to be more densely inhabited (116.05±22.69 ind./ha) by birds than Rasomati (76.55±26.47 ind./ha). Density increased by 44.6% at Nararthali and by 59% at Rasomati over the years of the study, from 2008 to 2015. Winter visitors increased considerably at Nararthali (66.2%), while a 71.1% decrease at Rasomati clearly indicated degradation of habitat quality at that site during the later years. Luxuriant growth of <italic>Eichhornia crassipes, siltation, poor maintenance and unregulated tourist activities were the key factors leading to the rapid degradation of Rasomati. Nararthali, on the other hand, a well-managed wetland habitat, showed an increasing trend in bird densities. Therefore, poor</italic> habitat management and rapid habitat alterations were observed to be the main reasons for depletion of bird density in the wetlands of eastern sub-Himalayan forest regions.</p></abstract>ARTICLEtrue Analysis of Orientation Cage Field Data – A Case Study of Headings of the Blackcap, , at the Bukowo/Kopań Ringing Site in Poland<abstract><title style='display:none'>Abstract</title><p>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/Kopań, 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.</p><p>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.</p></abstract>ARTICLEtrue Autumn Migration of the Citrine Wagtail, Motacilla Citreola, in the Lviv Region (W. Ukraine) During its Range Expansion<abstract><title style='display:none'>Abstract</title><p>The Citrine Wagtail has been gradually expanding its breeding range from Asia westward into Europe since the middle of the last century. New breeding records of this species further to the west of Europe have emerged during the last several decades. The distribution of the Citrine Wagtail in Western Ukraine began at the end of the last century. A total of 48 Citrine Wagtails were ringed in August 1995–2016 at the Cholgynskyy ornithological reserve (West-Ukrainian Ornithological Station). The birds were recorded mainly in the first half of August, peaking from the beginning of the second decade to the middle of the month. At the beginning of August there were wagtails in different stages of moult. Adult moulted birds were recorded from the beginning of the second decade of August, while juvenile birds underwent partial moult during the first part of the month. The mean weight of adult moulted birds was higher than that of juveniles. At the beginning of August many Citrine Wagtails were lean, without fat reserves, with the mean fat class increasing by the end of the month. The autumn passage of <italic>M. citreola</italic> took place in W. Ukraine. Birds stay in the shallow waters, pastures, and reed beds to feed, overnight, moult and gain fat reserves for migration.</p></abstract>ARTICLEtrue of morphometric parameters within the Savi's Warbler () population in eastern Poland<abstract xml:lang="en"><title style='display:none'>Variation of morphometric parameters within the Savi's Warbler (<italic>Locustella luscinioides</italic>) population in eastern Poland</title><p>Characteristics of the intra-populational variation of morphological parameters in the Savi's Warbler is based on measurements of 512 individuals caught in the breeding seasons of 1989-1998 in the Bagno Ławki peatbog (the southern basin of the Biebrza river valley). In the studied population, adult Savi's Warblers had longer and more rounded wing, longer tail and larger body mass than young individuals. Moreover, significant differences in the length of allula and 1<sup>st</sup> primary were found between these age classes. The range of wing length noted in this population, with the maximum value of 78 mm, distinctly exceeded the range of this parameter described for European populations of the Savi's Warbler. The average lengths of wing, tail allula and tarsus were distinctly higher in males than in females. Sexes did not differ in body mass, Kipp's distance and wing pointedness index. In the studied population, a distinct long-term variability of tail length, Kipp's distance, wing-tip pointedness index and tarsus length was found in young birds. In adults such variability was found only in tarsus length. The paper discusses possible reasons for the long-term variability of studied parameters.</p></abstract>ARTICLEtrue of migrant Blackcaps () on autumn passage through the Polish Baltic coast<abstract xml:lang="en"><title style='display:none'>Stop-over of migrant Blackcaps (<italic>Sylvia atricapilla</italic>) on autumn passage through the Polish Baltic coast</title><p>In this analysis, data on Blackcaps caught on autumn migration at the Operation Baltic stations: Bukowo-Kopań (54°28'N, 16°25'E) in 1984-1999 and Mierzeja Wiślana (54°21'N, 18°19'E) in 1982-1999 (in period: 14 August - 1 November) were used.</p><p>Total percentage of stopping-over (retrapped) Blackcaps was 11.6% at Mierzeja Wiślana and 7.9% at Bukowo-Kopań station. On average birds stayed longer at Mierzeja Wiślana (median - 5 days) than at Bukowo-Kopań (median - 4 days). Most probably, the Blackcap stop-over length and frequency depended on the food abundance in the area. Initial weight and fat load of birds retrapped later in the season were on average lower than of those caught only once, what suggests that birds stop-over to replenish their energy deficits. Weight and fat changes were influenced by the stop-over length. Individuals that left early, <italic>i.e.</italic> 1-2 days after ringing, not only did not gain energy, but also lost the reserves they had on their arrival. As the season progressed, birds tended to stop-over for a shorter time. The density of individuals already present in the studied area did not affect the decision of migrating birds to stop-over.</p></abstract>ARTICLEtrue and settling patterns of Sedge Warblers () in the Czech Republic and Slovakia - an analysis of ringing recoveries<abstract xml:lang="en"><title style='display:none'>Movements and settling patterns of Sedge Warblers (<italic>Acrocephalus schoenobaenus</italic>) in the Czech Republic and Slovakia - an analysis of ringing recoveries</title><p>In total, 1655 ringing recoveries of 1492 Sedge Warblers ringed or recovered in the Czech Republic and Slovakia were analysed in respect of breeding site fidelity, natal philopatry and movements. Out of 128 recoveries of adult birds from the breeding season, 96% came from the same locality showing a considerable breeding site fidelity. Out of 9 recoveries of birds ringed in nests and subsequently recovered during following breeding seasons, 8 settled at their birthplaces, only 1 male was found 26 km away from its native locality. After fledging, some juveniles dispersed in directions different from the migration routes. One young bird was recovered on its juvenile dispersal at the age of 35 days. On their migration to winterquarters, Sedge Warblers headed initially between south-west and south-east. The highest concentration of recoveries was situated in the Pannonian Lowland. Birds from the eastern Baltic region and Scandinavia often migrate through the territory of the Czech Republic and Slovakia. The only winter record came from southern France.</p></abstract>ARTICLEtrue analysis of an urban population of the Blackbird () in Szczecin in Poland<abstract xml:lang="en"><title style='display:none'>Biometrical analysis of an urban population of the Blackbird (<italic>Turdus merula</italic>) in Szczecin in Poland</title><p>In years 1996-2001, a biometrical investigation of an urban population of the Blackbird was conducted in two parks of Szczecin. Altogether, 388 birds were measured, including 191 females and 197 males. Adult females were bigger than young females (in all analysed parameters). Among males there were differences in wing, tail and total head lengths. In both sexes the strongest correlation occurred between wing and tail measurements and between bill and total head lengths. The body mass of females did not depend on their age and was not changing significantly in the course of year. However, in the case of males the young birds were lighter than the adults. Moreover, the males caught in winter were heavier than those caught in spring.</p></abstract>ARTICLEtrue preferences of the Reed Warbler () and the Sedge Warbler () on autumn migration at Lake Drużno (N Poland)<abstract xml:lang="en"><title style='display:none'>Directional preferences of the Reed Warbler (<italic>Acrocephalus scirpaceus</italic>) and the Sedge Warbler (<italic>A. schoenobaenus</italic>) on autumn migration at Lake Drużno (N Poland)</title><p>In 2000, during the whole autumn migration period, Reed Warblers (212 indiv.) and Sedge Warblers (205 indiv.) were tested with Busse's method (Busse 1995) for directional behaviour at Lake Drużno ringing site. Distributions of scratches, reflecting cage activity of an individual, were tested for uniformity and more than 97% showed directional behaviour of tested birds. The data were elaborated using non-standard method for evaluation of circular data proposed by Busse and Trocińska (1999) that allows to show multi-modal distributions.</p><p>Results show that as much as around 55% of obtained headings point at directions reversed in relation to the normal direction of autumn migration. They suggest that pronounced number of individuals show axial behaviour in the cage. Causes of this phenomenon are still vague and it was decided that directional behaviour will be discussed after reversing northward headings by the doubling the angle method (adding 180°). Then main directions of headings were set as WSW, SSW and SE. They were confronted with available ringing recovery data and quite high (10-12° difference) or even very high (WSW "beam" of migration of Reed Warblers - 5° difference) accordance was found. Using, for the comparison, the same method to the Lesser Whitethroat (<italic>Sylvia curruca</italic>) data published elsewhere, an excellent agreement between cage data and ringing recoveries at the level 2° only was found. This can be treated as a check of the field and evaluation methods used for basic data presented in the paper. The heading pattern changed in the course of autumn migration and in subsequent periods different headings dominated. The most clear it was for the Reed Warbler data. However, this problem still needs further analyses.</p></abstract>ARTICLEtrue Index to Estimate the Wing Area in A Small Passerine, Using the Blue Tit () As A Case Study<abstract xml:lang="en"><title style='display:none'>An Index to Estimate the Wing Area in A Small Passerine, Using the Blue Tit (<italic>Cyanistes caeruleus</italic>) As A Case Study</title><p>In this paper we suggest two new indices that can be used to estimate passerines' wing area. The first is a simplified index that considers wing pointedness and the width of each primary, the second is an extended index that also considers the length of the forearm. Using the Blue Tit as an example, we show that the sum of the width of all remiges is correlated with the maximum length of the folded wing (<italic>r<sub>p</sub></italic> = 0.42, <italic>p</italic> = 0.020, <italic>N</italic> = 30). The length of the ulna is correlated with the maximum length of the folded wing (<italic>r<sub>p</sub></italic> = 0.56, <italic>p</italic> = 0.005, <italic>N</italic> = 24). The two indices were derived from measurements of the wing length and the wing formula of birds caught at ringing stations. The indices can be used to analyse materials the stations have collected over the past 50 years. We also discuss how these indices can be applied in intra- and interspecific comparisons and to data collected using different standard methods.</p></abstract>ARTICLEtrue Temporarily Affects Time Budgets of Large Gulls<abstract xml:lang="en"><title style='display:none'>Wing-Tagging Temporarily Affects Time Budgets of Large Gulls</title><p>We studied behaviour of large gulls recently marked with wing-tags at loafing sites at an inland refuse dump using focal birds. During the first 3-4 weeks after marking, wing-tagged gulls spent more time preening at the refuse dump than unmarked birds, which usually did not preen there, while no difference between those two groups was observed at other sites. The possible reasons for preening on the refuse dump are that marked gulls either avoided flying to the loafing water because wing-tags impaired their flight, or showed displacement behaviour.</p></abstract>ARTICLEtrue Characteristics of Daytime Bird Migration in Israel: Radar Monitoring Data<abstract xml:lang="en"><title style='display:none'>Some Characteristics of Daytime Bird Migration in Israel: Radar Monitoring Data</title><p>In addition, it is of high importance to have statistics on seasonal transcontinental bird migrations in order to perform long-term planning of air traffic, especially in the areas crowded with aircraft.</p><p>We analysed the radar data collected over several years, and on this basis determined the main statistical characteristics of daytime bird flights over central Israel, including: (1) average and maximum flight altitudes, (2) time of the day and the season when bird migration is especially intensive, (3) dominating directions and velocities of flights.</p><p>It was found that average daily altitude maximums of bird flights (in relation to the sea level) were within the range of 1200-3500 m in autumn, and within the range of 1000-2700 m in spring. The absolute flight maximum reached 4300 m in autumn and 3700 m in spring. In autumn, flight altitudes were higher than in spring.</p><p>The altitudes of maximum bird concentrations reached 600 m in autumn, and only in rare cases rose to 650 m, while in spring the corresponding figures were 500 and 600 m. Both in spring and in autumn, the average altitude of maximum bird concentration was located within the range of 250-400 m.</p><p>The dominant flight direction for day migration was 190-220° in autumn and 10-50° in spring.</p><p>In our study, we did not observe any pronounced impact of wind direction on the direction of bird flights, neither close to the ground level nor at the height of 600 m. In Israel, both in autumn and in spring, the winds have a distinct occidental component, and at the height of 600 m the dominant wind directions are W-NW in autumn and W-SW in spring, <italic>i.e.</italic> at the angle of approximately 90° in relation to the directions of seasonal bird migrations.</p><p>The average ground-speed of seasonal migrations was found to be 14 m/s in spring and 15 m/s in autumn, the minimum and maximum ground-speed values of 8 and 18 m/s, respectively. At the same time, average monthly grounds-speed values at the altitude of 600 m, at 11.00 <italic>a.m.</italic> local time, were found to be within the range of 4-7 m/s in autumn and 3-6 m/s in spring.</p><p>The peak of day migration intensity was observed within the time interval from 12.00 to 1.00 <italic>p.m.</italic> The spring migration started at the beginning of March, reached its monthly peak in April and came to the end in late May. The autumn migration started at the middle of August, reached its monthly peak in September and came to the end in November.</p><p>The results obtained in the present study should be applied for ensuring air-traffic safety in periods of bird migration and also can be of special interest for ornithologists.</p></abstract>ARTICLEtrue Migration Dynamics and Biometrical Differentiation of the Dunnock () Passing the Southern Baltic Coast<abstract xml:lang="en"><title style='display:none'>Autumn Migration Dynamics and Biometrical Differentiation of the Dunnock (<italic>Prunella modularis</italic>) Passing the Southern Baltic Coast</title><p>The aim of this study is to determine biometrical differentiation among Dunnocks caught at the two ringing sites (Bukowo-Kopań and Mierzeja Wiślana) located on the southern Baltic coast. The distance between those two stations covers 190 km. The material was collected during autumn fieldwork of the Operation Baltic in 1961-2003. The material used for biometrical analysis comprises only immature birds from the period of the most intensive migration, when the numbers of caught individuals allowed to compare the results for both stations. The seasonal dynamics at both sites was pooled for 43 years of catching. Medians of autumn migration for the stations were significantly different. A shift of the median for the eastern site (Mierzeja Wiślana) by 6 days after the median for the western site (Bukowo-Kopań) suggested different origins of birds migrating through the stations. The analysis of standard deviations for the studied biometrical parameters confirms an intra-seasonal change in proportions of birds probably originating from different areas in Europe.</p></abstract>ARTICLEtrue