European Robin Erithacus Rubecula Research Articles

Is the settlement of a winter territory in the European Robin Erithacus rubecula triggered by the arrival of conspecific migrants?

Is the settlement of a winter territory in the European Robin Erithacus rubecula triggered by the arrival of conspecific migrants?

A preliminary study of the winter roosting behaviour of four woodland passerines

ABSTRACT Capsule Radio-tracking of four woodland passerine species reveals variation in winter roost site selection within and between species. Aims To evaluate methods for studying winter roosting behaviour in woodland passerines and to collect preliminary data on intra- and inter-specific differences in roost site characteristics and spatial arrangement. Methods Ten woodland birds (three Eurasian Blackbirds Turdus merula, three Dunnocks Prunella modularis, two Great Tits Parus major and two European Robins Erithacus rubecula), were fitted with a tail-mounted Lotek PicoPip AG337 VHF radio tag (January to March 2022). Tagged birds were located by triangulation, and nightly winter roost locations identified and characterized. A geographic information system was used to quantify roost site fidelity, roosting height and types of habitats used. Results Manual tracking of birds with radio tags is a cost effective and appropriate method for studying passerine winter roosting behaviour. Sample sizes were too small to allow exploration of significant differences between sites, age and sex. European Robins showed the greatest site fidelity in relation to between-night roost positions, with Eurasian Blackbird, Great Tit and Dunnock being more variable in the sites chosen between nights. Eurasian Blackbird and Great Tit roost sites were generally higher above the ground (up to 6 m), compared to European Robins and Dunnocks (all sites less than 4 m above the ground). Eurasian Blackbirds varied the most in the number of habitats used for roost sites, and European Robins showed the least variation. Only three out of 11 habitat types (bramble Rubus sp, laurel Prunus sp. and Sycamore Acer pseudoplatanus with Ivy Hedera helix) were used by more than one species as a roosting habitat. Conclusion Further research should focus on: (1) habitat use in relation to relative availability; (2) increasing samples sizes to allow comparison of factors such as age, sex and sites; (3) the impact of supplementary feeding on roosting behaviour; (4) quantifying the thermal properties of roost sites.

Estimating survival in continuous space from mark-dead-recovery data — Towards a continuous version of the multinomial dead recovery model

Understanding spatially varying survival is crucial for understanding the ecology and evolution of migratory animals, which may ultimately help to conserve such species. We develop an approach to estimate an annual survival probability function varying continuously in geographic space, if the recovery probability is constant over space. This estimate is based on a density function over continuous geographic space and the discrete age at death obtained from dead recovery data. From the same density function, we obtain an estimate for animal distribution in space corrected for survival, i.e., migratory connectivity. This is possible, when migratory connectivity can be separated from recovery probability. In this article, we present the method how spatially and continuously varying survival and the migratory connectivity corrected for survival can be obtained, if a constant recovery probability can be assumed reasonably. The model is a stepping stone in developing a model allowing for disentangling spatially heterogeneous survival and migratory connectivity corrected for survival from a spatially heterogeneous recovery probability. We implement the method using kernel density estimates in the R-package CONSURE. Any other density estimation technique can be used as an alternative. In a simulation study, the estimators are unbiased but show edge effects in survival and migratory connectivity. Applying the method to a real-world data set of European robins Erithacus rubecula results in biologically reasonable continuous heat-maps for survival and migratory connectivity.

Migratory departures of Robins during spring migration at Skagen, Denmark

SUMMARY We tracked departures of European Robins Erithacus rubecula stopping over during spring migration at Skagen, Denmark, and facing a sea crossing of more than 50 km. The Robins stopped over on average for 3.8 days (range 1–14 days, n = 15) with departure days being slightly warmer than stopover days (1.5°C warmer, P = 0.003). Departures were concentrated in the evening, on average during astronomical twilight, and toward the northeast (µ = 33.3°, r = 0.499, P = 0.021). The mean northeasterly departure direction is close to the standard migration direction. Most birds probably crossed the sea to Sweden and we observed no obvious reversed departure directions.

Autumn fueling behavior in passerines in relation to migratory distance and daylength.

Songbirds have evolved diverse strategies to cope with seasonality, including long-, medium-, and short-distance migration. There is some evidence that birds with a longer migration distance deposit fuel faster. However, most studies focus on long-distance migrants. Comparisons between species with different migration distances are necessary to broaden our understanding of fueling capacity in migratory birds. We present maximum fuel deposition rates of five songbird species migrating along the southeast coast of Sweden in autumn with migration distances ranging from long (neotropical migrant) to short (partial/irruptive migrant) (Willow Warbler Phylloscopus trochilus, Lesser Whitethroat Curruca curruca, Common Chiffchaff P.collybita, European Robin Erithacus rubecula, and Blue Tit Cyanistes caeruleus). The birds were fed ad libitum in captivity and were exposed to either extended or natural daylength. All species ceased to increase in mass when they reached a certain fuel load, generally corresponding to migration distance, despite unlimited access to food and ample time for foraging. Blue Tits, Willow Warblers, and Lesser Whitethroats had the highest fuel deposition rates with extended daylength (19%, 20%, and 20%, respectively), and about 13% with natural daylength, which is comparable to the highest rates found in migratory songbirds in nature. European Robins and Common Chiffchaffs that winter in the temperate Mediterranean had the lowest fuel deposition rates (12% and 12% with extended daylength, respectively). Our results suggest that the long- and short-distance migrants in this study have developed an extreme capacity for rapid refueling for different reasons; speedy migration to distant wintering grounds or winter survival in Scandinavia. This study contributes to our current knowledge of maximum fuel deposition rates in different species and the limitations posed by daylength. We highlight the need for future studies of species with different migration strategies in order to draw broad conclusions about fueling strategies of migratory birds.

Seed Dispersal by an Invasive Exotic Bird in Europe

Native birds play a critical role in seed dispersal. The introduction of a new species may result in unpredictable effects on an ecosystem, namely in terms of seed dispersal. The Red-billed Leiothrix Leiothrix lutea is a frugivorous species native to Asia, whose potential role as seed disperser has not yet been analysed in its introduced range in Europe. We compared the role of Leiothrix with that of Eurasian Blackcap Sylvia atricapilla and European Robin Erithacus rubecula, which are among the native species with seed dispersal roles in Europe. We compared seed expelling behaviour among species (defecation or regurgitation of seeds), which can potentially shape seed dispersal, depending on whether the seeds germinate following expulsion. Field work was conducted in Central Portugal between November 2014 and January 2015 and included bird captures to collect faecal samples, followed by faecal analysis to check for the presence of seeds. We also surveyed plant species abundance and fruit availability in the study site. The feeding and seed defecation behaviour of Leiothrix closely matched that of Robins, as most individuals of both species consumed fruits without ingesting seeds and their faeces mainly contained plant material and few seeds. On the contrary, more than half of Blackcap faeces contained seeds. All three species ate similar plant species. Although Leiothrix faeces indicate that this species primarily eats fruits without ingesting seeds; a small fraction of faeces samples (c. 13%) contained seeds. Our results suggest that Leiothrix has low potential to be a seed disperser in Central Portugal and probably elsewhere.

Estimation in the multinomial reencounter model – Where do migrating animals go and how do they survive in their destination area?

Spatial variation in survival has individual fitness consequences and influences population dynamics. Which space animals use during the annual cycle determines how they are affected by this spatial variability. Therefore, knowing spatial patterns of survival and space use is crucial to understand demography of migrating animals. Extracting information on survival and space use from observation data, in particular dead recovery data, requires explicitly identifying the observation process.We build a fully stochastic model for animals marked in populations of origin, which were found dead in spatially discrete destination areas. The model acts on the population level and includes parameters for use of space, survival and recovery probability. It is based on the division coefficient and the multinomial reencounter model. We use a likelihood-based approach, derive Restricted Maximum Likelihood-like estimates for all parameters and prove their existence and uniqueness.In a simulation study we demonstrate the performance of the model by using Bayesian estimators derived by the Markov chain Monte Carlo method. We obtain unbiased estimates for survival and recovery probability if the sample size is large enough. Moreover, we apply the model to real-world data of European robins Erithacus rubecula ringed at a stopover site. We obtain annual survival estimates for different spatially discrete non-breeding areas. Additionally, we can reproduce already known patterns of use of space for this species.

Wintering phenology and site fidelity of European Robins (Erithacus rubecula) in an eastern Mediterranean wintering area (Aves: Passeriformes)

The European Robin (Erithacus rubecula) is a partial migrant in Central Europe and the Eastern Mediterranean known as a wintering area. Little is known about the behaviour in the winter. I assessed the wintering phenology by using capture-recapture methods in a coastal area in southern Turkey. Over three wintering seasons, 76 European Robins were captured with mist-nets. Ten of them were recaptured in the following wintering seasons and another after two seasons. Recaptures peaked in November (26.5%) and December (26.5%) and then declined progressively to February (14.7%). Our results suggest a high level of site fidelity in the wintering area in subsequent years.

First Breeding Record of the European Robin Erithacus rubecula in Lebanon 2020

European Robin Erithacus rubecula has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion. The population trend appears to be increasing and the size is extremely large. For these reasons the species is evaluated as Least Concern. In Europe, the breeding population is estimated to number 58,700,000-90,500,000 pairs, which equates to 117,000,000-181,000,000 mature individuals. This species is found in forest undergrowth and edge, preferring conifer tracts in some parts of its range and deciduous woodland in others. It uses copses and adjacent open land, farmland woodlots, thickets along watercourses, hedgerows with some tall trees, orchards, gardens and parks and is also found in urban areas in parts of Europe. It requires cool shade, medium-height cover with perches, and patches of bare ground. Breeding occurs from early April to mid-June in the U.K., from the end of April to late July in central Europe and from mid-May in northern Russia and mid-April in southern Russia. On the 28th of April 2020, I was birdwatching in Horsh Ehden Nature Reserve Zgharta-Ehden District, north Lebanon when I encountered a couple of European Robins carrying insects to a nest in a hole in a big rock near the river. Following the birds, they entered the whole and went outside immediately watching me cautiously. I went to see what’s inside that rock and I saw the nest of the European Robin with 3 nestling inside of it. Later after 3 weeks I went again to see the nest I found the juveniles wandering around it. Reporting it to Dr Ghassan Ramadan Jaradi, it was accepted as a first breeding record of this species to Lebanon. Later on, I was able to identify many juvenile individuals near the same location.

Characteristics and selection of nest sites of the flexible cavity-nester, the European robin Erithacus rubecula, in the temperate primeval forest (Białowieża National Park, Poland)

Despite its broad range and high abundance, nest sites of the European robin Erithacus rubecula, a small forest passerine, are rarely characterised, and most studies refer to human-transformed habitats. In this paper, we describe the species’ nest sites in the natural conditions of a primeval forest. We also investigate robin preferences to address nest site selection which can only be assessed if the availability of potential nest sites is known. We studied robins’ nest sites in Białowieża National Park, eastern Poland, on three study plots (~30 ha each) in 2016–2019. Among all nests found (n = 165), the majority (118, ~72%) were found in tree holes, followed by ground nests (25, ~15%) and root-soil plates (22, ~13%). When the availability of cavities and root-soil plates is accounted for, it appears that robins preferred tree holes over plates. Robins appeared to be weakly selective in respect to tree species, preferring hornbeam Carpinus betulus, small-leaved lime Tilia cordata and Norway spruce Picea abies over other trees. Since both cavities and root-soil plates are superabundant in the Białowieża Forest, but scarce or absent in the heavily transformed robin breeding habitats of Western Europe (parks, orchards, hedgerows or managed forests), ground-nesting may predominate there simply due to these choice limits. In summary, our results provide a basis for understanding how original nest-site choices that evolved in natural, unmodified habitats can change when a species adapts to human-transformed habitats.

Ticks (Acari: Ixodidae) parasitizing migrating and local breeding birds in Finland

Ticks are globally renowned vectors for numerous zoonoses, and birds have been identified as important hosts for several species of hard ticks (Acari: Ixodidae) and tick-borne pathogens. Many European bird species overwinter in Africa and Western Asia, consequently migrating back to breeding grounds in Europe in the spring. During these spring migrations, birds may transport exotic tick species (and associated pathogens) to areas outside their typical distribution ranges. In Finland, very few studies have been conducted regarding ticks parasitizing migrating or local birds, and existing data are outdated, likely not reflecting the current situation. Consequently, in 2018, we asked volunteer bird ringers to collect ticks from migrating and local birds, to update current knowledge on ticks found parasitizing birds in Finland. In total 430 ticks were collected from 193 birds belonging to 32 species, caught for ringing between 2018 and 2020. Furthermore, four Ixodes uriae were collected from two roosting islets of sea birds in 2016 and 2020. Ticks collected on birds consisted of: Ixodes ricinus (n = 421), Ixodes arboricola (4), Ixodes lividus (2) and Hyalomma marginatum (3). Ixodes ricinus loads (nymphs and larvae) were highest on thrushes (Passeriformes: Turdidae) and European robins (Erithacus rubecula). The only clearly imported exotic tick species was H. marginatum. This study forms the second report of both I. uriae and I. arboricola from Finland, and possibly the northernmost observation of I. arboricola from Europe. The importation of exotic tick species by migrating birds seems a rare occurrence, as over 97% of all ticks collected from birds arriving in Finland during their spring migrations were I. ricinus, a species native to and abundant in Finland.

Massive Infection of Lungs with Exo-Erythrocytic Meronts in European Robin Erithacus rubecula during Natural Haemoproteus attenuatus Haemoproteosis.

Simple SummaryHaemoproteus parasites are cosmopolitan bird pathogens belonging to the order Haemosporida (Apicomplexa). A majority of the described species are transmitted by Culicoides biting midges, which inject infective stages (sporozoites) in birds during blood meals. The sporozoites initiate tissue merogony, resulting in numerous merozoites, part of which penetrate red blood cells and produce blood stages (gametocytes), which are infective for vectors. The blood stages of Haemoproteus parasites have been relatively well-investigated, although tissue stages and patterns of their development remain unidentified in the majority of Haemoproteus species. Nevertheless, they often damage various organs which makes them important for bird health. This study contributes new knowledge about tissue merogony of Haemoproteus attenuatus, which parasitize birds of the Muscicapidae. Naturally infected European robins Erithacus rubecula were caught in Lithuania during autumnal migration. Parasites were identified using morphological features of gametocytes and DNA sequence analysis. Organs of infected birds were examined using histological methods. Tissue stages (meronts) were present only in the lungs, where they were numerous and markedly varied in shape, size and maturation stage. Description of meronts was provided and molecular phylogenetic analysis identified closely related lineages that could present similar exo-erythrocytic development in lungs. Lung damage caused by meronts of H. attenuatus and closely related lineages is worth attention due to their possible implications on a bird’s health.Haemoproteus species are widespread avian blood parasites belonging to Haemoproteidae (Haemosporida). Blood stages of these pathogens have been relatively well-investigated, though exo-erythrocytic (tissue) stages remain unidentified for the majority of species. However, recent histopathological studies show that haemoproteins markedly affect bird organs during tissue merogony. This study investigated the exo-erythrocytic development of Haemoproteus (Parahaemoproteus) attenuatus (lineage hROBIN1), the common parasite of flycatchers (Muscicapidae). Naturally infected European robins Erithacus rubecula were examined. Parasite species and lineage were identified using microscopic examination of blood stages and DNA sequence analysis. Parasitaemia intensity varied between 0.8 and 26.5% in seven host individuals. Organs of infected birds were collected and processed for histological examination. Tissues stages (meronts) were seen in six birds and were present only in the lungs. The parasites were usually located in groups and were at different stages of maturation, indicating asynchronous exo-erythrocytic development. In most parasitized individuals, 100 meronts were observed in 1 cm2 section of lungs. The largest meronts reached 108 µm in length. Mature meronts contained numerous roundish merozoites of approximately 0.8 µm in diameter. Megalomeronts were not observed. Massive merogony and resulting damage of lungs is a characteristic feature during H. attenuatus infections and might occur in related parasite lineages, causing haemoproteosis.

First microsatellite markers for the European Robin (Erithacus rubecula) and their application in analysis of parentage and genetic diversity

The European Robin is a small passerine bird associated with woodlands of Eurasia and North Africa. Despite being relatively widespread and common, little is known of the species’ breeding biology and genetic diversity. We used Next Generation Sequencing (NGS) to develop and characterize microsatellite markers for the European Robin, designing three multiplex panels to amplify 14 microsatellite loci. The level of polymorphism and its value for assessing parentage and genetic structure was estimated based on 119 individuals, including seven full families and 69 unrelated individuals form Poland’s Białowieża Primaeval Forest and an additional location in Portugal. All markers appeared to be highly variable. Analysis at the family level confirmed a Mendelian manner of inheritance in the investigated loci. Genetic data also revealed evidence for extra-pair paternity in one family. The set of markers that we developed are proven to be valuable for analysis of the breeding biology and population genetics of the European Robin.

Bactericidal activity of avian complement: a contribution to understand avian-host tropism of Lyme borreliae

Complement has been considered as an important factor impacting the host–pathogen association of spirochetes belonging to the Borrelia burgdorferi sensu lato complex, and may play a role in the spirochete’s ecology. Birds are known to be important hosts for ticks and in the maintenance of borreliae. Recent field surveys and laboratory transmission studies indicated that certain avian species act as reservoir hosts for different Borrelia species. Nevertheless, our current understanding of the molecular mechanisms determining host tropism of Borrelia is still in its fledgling stage. Concerning the role of complement in avian-host tropism, only a few bird species and Borrelia species have been analysed so far. Here, we performed in vitro serum bactericidal assays with serum samples collected from four bird species including the European robin Erithacus rubecula, the great tit Parus major, the Eurasian blackbird Turdus merula, and the racing pigeon Columba livia, as well as four Borrelia species (B. afzelii, B. garinii, B. valaisiana, and B. burgdorferi sensu stricto). From July to September 2019, juvenile wild birds were caught using mist nets in Portugal. Racing pigeons were sampled in a loft in October 2019. Independent of the bird species analysed, all Borrelia species displayed an intermediate serum-resistant or serum-resistant phenotype except for B. afzelii challenged with serum from blackbirds. This genospecies was efficiently killed by avian complement, suggesting that blackbirds served as dead-end hosts for B. afzelii. In summary, these findings suggest that complement contributes in the avian–spirochete–tick infection cycle and in Borrelia-host tropism.

Is nesting in closed nestboxes advantageous for the European Robin (Erithacus rubecula)?

BackgroundThe European Robin (Erithacus rubecula) is eurytopic in its choice of nest site, which can be either half-open or closed, and situated either on the ground or at a height of several meters. On occasion, robins also nest in closed nestboxes, though generally only solitary such cases are documented, albeit that dozens of such events can be recorded during the course of some long-term studies. However, until now, nobody has summarised the peculiarities of robins nesting in closed nestboxes.MethodsIn the period 1978–2020, wooden tit and starling nestboxes were inspected regularly at five study sites in Lithuania, this totaling more than 18,000 nestbox-seasons. During these inspections, 90 cases of robins nesting in the nestboxes were recorded. Publications on this topic from the entire robin distribution range were reviewed.ResultsRobins prefer to nest in old large-sized fairly shallow nestboxes with wide entrance holes, for example starling nestboxes or tit nestboxes with enlarged entrance holes. Increased numbers of nestboxes being occupied by robins were recorded for 3–8 years in row. In Lithuania, nesting success in nestboxes is not higher than compared with nesting on the ground. Tree climbing mammals, Pine Martens (Martes martes), Hazel Dormice (Muscardinus avellanarius), Edible Dormice (Glis glis) and Forest Dormice (Dryomys nitedula), are the main predators of robin nests in nestboxes.ConclusionsSome geographic variation was found in the occurrence of robins nesting in nestboxes with more such cases recorded in central and southern parts of the range. Possibly robins are more philopatric in these parts of the range, with the same females or their offspring nesting in nestboxes for several years in row. In areas inhabited by dormice, nesting in closed nestboxes is not advantageous for robins.

Root Plates as Nesting Sites for Eurasian Wrens Troglodytes troglodytes in a Forest Undergoing Renaturalisation

Upturned root systems are used by several species of birds as nesting sites. The primeval lowland temperate forests are the crucial the source of information with this respect. The aim of the study was to characterise the root plates as nesting sites in a forest covered by a reserve protection system for about 20 years. The research was conducted between 2016–2018 in south-eastern Poland. In the area examined, nests of the Eurasian Wren Troglodytes troglodytes and the European Robin Erithacus rubecula were found to occupy 19.9% and 2.1% of root plates in uprooted trees, respectively. Among root plates with wren nest, Scots Pine accounted 36.8%, subsequently Norway Spruce 28.9%, and Silver Birch 18.4%. Inclined root plate and root plate of large surface were often chosen by Wrens for building a nest. A week positive correlation was found between the height at which the nest was built and the height of the root plate.

Isospora oliveirai n. sp. (Chromista: Miozoa: Eimeriidae) from the Greenish Schiffornis Schiffornis virescens (Lafresnaye, 1838) (Passeriformes: Tyranni: Tityridae) in South America.

Coccidia are obligatory intracellular parasites with at least one intestinal phase in their life cycles, being Isospora Schneider, 1881 the main coccidian genus related to the order Passeriformes. However, there is no record of isosporans from the passerine family Tityridae, which is the family of the greenish schiffornis Schiffornis virescens (Lafresnaye, 1838). This study aimed to examine the faeces from a greenish schiffornis S. virescens captured in the Itatiaia National Park, State of Rio de Janeiro, Southeastern Brazil, to determine what coccidian parasites were present. Only one specimen of Schiffornis virescens was captured with mist nets. Coccidian oocysts were recovered from the fecal samples by flotation in Sheather's saturated solution. Morphological observations, line drawings, photomicrographs and measurements were made in optical microscopy and digitally edited. The molecular analysis included the study of the sequence of the mitochondrial cytochrome c oxidase subunit 1 (COI) gene, with phylogenetic reconstructions based on the Neighbor-Joining and Maximum Likelihood analysis. An Isospora sp. considered as new to science is described and identified from Schiffornis virescens (Lafresnaye, 1838). Isospora oliveirai n. sp. has oocysts that are subspheroidal, 26.0 × 24.8μm, with rough, bilayered wall, c.2.5μm thick. Micropyle and oocyst residuum absent, but one to six polar granules are present. Sporocysts lemon-shaped, 18.1 × 10.9μm. The Stieda body is knob-like to half-moon-shaped and sub-Stieda is rounded. Sporocyst residuum is present, composed of scattered spherules of different sizes. Sporozoites are vermiform, with refractile bodies and nucleus. Molecular analysis at the COI gene exhibited similarity of 97% with Isospora serinuse Yang, Brice, Elliot et Ryan, 2015 from island canaries Serinus canaria (Linnaeus, 1758), and Isospora spp. from great tits Parus major (Linnaeus, 1758) and European robins Erithacus rubecula (Linnaeus, 1758). Based on the morphological and molecular features, I. oliveirai is considered as new to science and the first coccidian species recorded from Tityridae.

Mechanical and structural adaptations to migration in the flight feathers of a Palaearctic passerine.

Current avian migration patterns in temperate regions have been developed during the glacial retreat and subsequent colonization of the ice-free areas during the Holocene. This process resulted in a geographic gradient of greater seasonality as latitude increased that favoured migration-related morphological and physiological (co)adaptations. Most evidence of avian morphological adaptations to migration comes from the analysis of variation in the length and shape of the wings, but the existence of intra-feather structural adjustments has been greatly overlooked despite their potential to be under natural selection. To shed some light on this question, we used data from European robins Erithacus rubecula overwintering in Campo de Gibraltar (Southern Iberia), where sedentary robins coexist during winter with conspecifics showing a broad range of breeding origins and, hence, migration distances. We explicitly explored how wing length and shape, as well as several functional (bending stiffness), developmental (feather growth rate) and structural (size and complexity of feather components) characteristics of flight feathers, varied in relation to migration distance, which was estimated from the hydrogen stable isotope ratios of the summer-produced tail feathers. Our results revealed that migration distance not only favoured longer and more concave wings, but also promoted primaries with a thicker dorsoventral rachis and shorter barb lengths, which, in turn, conferred more bending stiffness to these feathers. We suggest that these intra-feather structural adjustments could be an additional, largely unnoticed, adaptation within the avian migratory syndrome that might have the potential to evolve relatively quickly to facilitate the occupation of seasonal environments.

Can measures for modelling bird flight be replaced by measures taken easily on live birds and museum skins?

ABSTRACT Usually, some measurements are taken from birds caught for ringing, for example to differentiate between species, subspecies or sexes, or to obtain a measure of body size or energy stores. However, the ecomorphological interpretation of standard measures of the flight apparatus is often difficult, because flight models need parameters that are not among the standard measures taken by field ornithologists. Therefore we evaluated on dead European Robins Erithacus rubecula and Eurasian Blackcaps Sylvia atricapilla how well a suite of measures that can be easily taken on a live bird is correlated with the aerodynamically relevant parameters wingspan, wing area, wing chord, aspect ratio and wing pointedness. We found that wing chord is well correlated with the length of secondary 2, wingspan with the length of the primary that forms the wingtip of the spread wing, and wing area with the length of the longest primary. Aspect ratio and wing pointedness were poorly correlated with alternative measures. Compound measures did not significantly improve these relationships, while some multivariate models did. From the limited data set of this study, it seems that aerodynamically relevant parameters can be substituted to a certain extent by measures that can easily be taken from live birds or museum skins. This may serve intraspecific studies in which data from live birds or museum skins are collected with the aim of interpreting their flight performance in a correlative way.

Migration and stopover ecology of European Robins Erithacus rubecula in an oleaster forest in southeastern Hungary

ABSTRACT Secondary wooded habitats provide suitable habitat for many bird species during autumn migration, and they also have an important role in migratory connectivity. In this study, we examined the migration timing and stopover ecology of the European Robins Erithacus rubecula migrating through a bird ringing station in southeastern Hungary. The ringing site is dominated by oleaster Elaeagnus angustifolia mixed with different berries and other shrubs and trees. The fieldwork covered the five years 2016–20, from early August to late October. For the analyses, we used data from a total of 725 ringed and 126 recaptured individuals. Our results show that these secondary habitats play an important role in the migration of this species. Birds migrated through the study site later than in other parts of Hungary, due to its southerly location. The rate of change in body mass was lower than that found at other locations in Europe, but the stopover duration was similar. The rate of change in body mass was influenced by the duration of stopover. Our findings highlight the importance of these secondary habitats in the farmland environment.