Search

To perform their long-distance postnuptial migration, trans-Saharan migratory passerines must refuel repeatedly at different stopover sites. But some stopover sites have a specific role because most of the reserves needed to cross large ecological barriers (e.g., sea or desert) are stored there. This is the case in the west of the Iberian Peninsula, which is the main fattening area for European pied flycatcher Ficedula hypoleuca before they cross the Sahara. Upstream, no sites have been sampled in Western Europe between Great Britain and the southern Iberian Peninsula. Southwestern France is a main postnuptial route for this species with funnel effect between the end of the Pyrenees barrier and the Atlantic Ocean. In this area, we estimated energetic parameters from capture–mark–recapture data obtained during standardized monitoring. The mean stopover duration was relatively high, estimated at 8.4 days after the first capture by a capture–mark–recapture model and at 16.8 days assuming a similar duration before the first capture. Individual minimum stopover durations of 23 and 28 days were recorded. Pied flycatchers were fattening at an average rate of 0.29 g day−1 (3.1% of lean body mass) consistent throughout the season and independent of initial body mass, supporting the idea that the area was targeted for fattening. Very high fuel deposition rates over short durations were observed in several individuals (from 5 to 13.3% of their lean body mass). The mean fuel load did not differ by age or year and averaged 33.8% of lean body mass. The mean fuel load of the 25% heaviest fraction of birds was 57.3%, providing a flight range covering 80% of the distance to the southern margin of the Sahara. Hence, the departure fuel load was insufficient to cross the Sahara. At least one additional stopover would be necessary in the Iberian Peninsula, but for a moderate extra fuel. Individuals fattening under time pressure coexisted with individuals in prolonged stopover. Both behaviors are on few specific sites. Although the Sahara is still far away, South-West France is not solely a transit region concentrating birds because of the Pyrenees barrier. It must be an area of high refueling.

[EN] Sexually and socially selected signals are predicated to express the present and past condition of individuals and thereby their capacity to cope with environmental challenges. The concentration of corticosterone in feathers (CORTf) has been validated as a marker of activation of the hypothalamic-pituitary axis in birds during feather development. Measurements of CORTf can thus express the physiological stress of migratory birds during non-breeding periods of the annual cycle when feathers moulted in the wintering range are analysed. Thus, negative trends of ornament expression with CORTf may be predicted. Unpigmented plumage patches may constitute signals of phenotypic quality and are used in many species in social interac-tions by both sexes. Pied Flycatchers of both sexes Ficedula hypoleuca show white forehead and wing patches during the breeding season, of which the forehead and part of the wing patch (tertials) are moulted on the wintering grounds before spring migration. These patches are used as signals in social and sexual interactions and their expression has been previ-ously related to several indicators of physiological status. We collected tertials of females during nestling provisioning in a Spanish population and determined their CORTf in the laboratory. CORTf was thus measured in some of the prenuptially moulted feathers used as signals of social dominance by breeding females. According to AICc model selection, CORTf turned up in all the best models explaining forehead patch size and in most best models for wing patch size when controlling for age and size. Both forehead and wing patch sizes were negatively related to CORTf, although the trend for wing patch size was not significant. This indicates that breeding females expressing large unpigmented patches experienced low levels of stress during the prenuptial moult in their winter quarters, or that strongly signalling individuals present a lower level of activation of the HPA axis. [AL] Soziale und für das jeweilige Geschlecht selektierte Signale sollen die gegenwärtige und vorangegangene Verfassung von Individuen anzeigen und damit ihre Fähigkeit, mit den Herausforderungen der Umwelt fertigzuwerden. Die Konzentration von Kortikosteron in den Federn (CORTf) wurde bei Vögeln während der Federentwicklung als Marker für die Aktivierung der Hypothalamus-Hypophysen-Achse validiert. Messungen des CORTf können daher den physiologischen Stress von Zugvögeln im Jahreszyklus außerhalb der Brutzeiten ausdrücken, wenn man im Überwinterungsgebiet bei der Mauser aus-gefallene Federn analysiert. Somit können möglicherweise negative Trends im gesamten Federkleid vorhergesagt werden. Unpigmentierte Stellen im Gefieder können Signale der phänotypischen Qualität darstellen und werden bei vielen Arten in sozialen Interaktionen von beiden Geschlechtern verwendet. Trauerschnäpper (Fidecula hypoleuca) beider Geschlechter zeigen während der Brutzeit weiße Stirn- und Flügelflecken; die Federn an Stirn und Teilen der Flügel mausern im Win-terquartier vor Beginn des Frühjahrszuges. Die Flecken werden in sozialen Interaktionen und zwischen den Geschlechtern als Signal eingesetzt, und ihr Ausprägungsgrad wurde bislang mit mehreren Indikatoren für die physiologische Verfassung in Verbindung gebracht. Wir sammelten die Federn von Weibchen einer spanischen Population während des Nestbaus und bestimmten deren CORTf im Labor. Somit wurde CORTf in Federn aus der Mauser vor der Begattung gemessen, die von brütenden Weibchen als Zeichen ihrer sozialen Dominanz benutzt werden. Bei der Prüfung des Alters und der Körpergröße tauchte unter den AICc-Modellen die CORTf zur Erklärung der Größe des Stirnflecks in allen bestgeeigneten Modellen auf, zur Erklärung der Größe der Flügelflecken in den meisten bestgeeigneten Modellen. Die Größe sowohl der Stirn- als auch der Flügelflecken korrelierte negativ mit CORTf, letztere allerdings nicht signifikant. Dies deutet darauf hin, dass brütende Weibchen mit großen pigmentfreien Flecken während der ersten Mauser im Winterquartier einem niedrigen Stresslevel ausgesetzt waren, oder dass starke Signale aussendende Einzeltiere ein niedrigeres Aktivitätsniveau der Hypothalamus-Hypophysen-Achse aufweisen. The study was supported by project CGL2017-83843-C2-1 from Ministerio de Economía, Industria y Competitividad (MINECO, Spanish Government).

Environmental pollution can exacerbate deterioration in fecundity with advancing age, directly via the toxic effects of pollutants or indirectly via pollution-related resource (e.g. dietary antioxidants) constraints. Since there are very few studies on age-related changes in reproduction with regard to pollution, we analyzed a long-term (25 years) set of reproduction data from a small insectivorous and migratory passerine bird, the Pied Flycatcher Ficedula hypoleuca, to determine whether female birds showed a faster age-related decrease in average breeding parameters in a metal-polluted area around a copper–nickel smelter than in the control area. In our population-level analysis, all the breeding parameters (clutch size, hatching success, fledging probability, and fledgling number) were lower in the polluted area. Nevertheless, none of them indicated a faster decrease with age in the polluted area. Clutch size and fledgling number increased after the first breeding, but showed no significant change later on. Hatching probability decreased slightly after the second breeding, while fledging probability showed no significant age-dependent variation. Our results suggest that moderate long-term pollution does not reduce the viability of our study population via a faster age-related decrease in fecundity.

Microbial relationships between birds and nesting environments are complex and remain poorly understood. Past studies have focused on between-nest variation in egg/chick bacterial profiles with little attention given to the microbial relationships between adult birds and their nests. Moreover, very little microbial research has included mycology despite fungi being prevalent in nesting environments and important correlates of fitness in chicks. In this study, we identified microbes associated with feathers, skin and nests of Pied Flycatchers Ficedula hypoleuca, an internationally-declining migrant songbird. From 75 samples, we isolated 50 bacterial OTUs (Operational Taxonomic Units; dominated by Enterococcus, Sanguibacter, Pseduomonas) and 63 fungal OTUs (dominated by Penicillium, Aspergillus), many of which had not previously been isolated from birds. Although females had significantly higher non-haemolytic bacterial OTU richness and males significantly higher fungal OTU richness, there was considerable diversity in actual OTUs isolated and thus there was no “typical” female, male, or nest microbial profile. Interestingly though, we show for the first time that the microflora of individual females is significantly more similar the microflora of her own nest than the site-level average of all nests. This suggests microbes are shared within female-nest pairs such that microbial communities start to converge. This is probably a two-way interaction as gut/skin microbes were isolated from nests and plant/soil microbes were isolated from females. Convergence was not seen for males, which probably reflects the role of the female as sole nest builder and egg incubator in this species. We discuss these findings in relation to microbial transfer pathways and avian nesting behaviour.

In some avian species, individuals spend most of their lives in complex social groups. A recent hypothesis argues that social complexity will drive complexity in signaling systems. According to this hypothesis, individuals living in more complex groups (larger and with greater diversity of interactions) require larger and more diverse repertoires of signals, compared to individuals living in groups that are relatively simple in social structure. Social complexity has also been argued to be an important driver of social cognition and cooperation. Although many of these arguments have been based on empirical findings with non-human primates, similar evidence is beginning to emerge from avian studies. Here, we discuss some of this avian evidence, with an emphasis on two model species: Carolina chickadees, Poecile carolinensis (Paridae), and pied flycatchers, Ficedula hypoleuca. In Carolina chickadees, variation in the structure of chick-a-dee calls influences behavior of receivers in pro-social and potentially cooperative ways in anti-predator and food detection contexts. In pied flycatchers, breeding individuals were much less likely to travel greater distances to assist in mobbing predators near their conspecific neighbors if those neighbors had failed to assist them in mobbing earlier. More research is needed to determine whether communicative complexity per se makes sophisticated social cognition possible, such as reconciliation and cooperation (and whether the latter might stem from reciprocal altruism or less cognitively demanding processes like conspecific by-product mutualism).

The association between skin bacterial communities and nestling growth is poorly understood. We estimated the abundance of heterotrophic bacteria on skin of nestlings and their association with growth in the pied flycatcher Ficedula hypoleuca. At two different nestling ages, we swabbed a delimited area of the naked belly skin of nestlings and measured them. Skin bacterial loads on day 13, but not on day 7, were positively associated with brood size and with nestling wing length. Larger broods develop in less hygienic conditions, which may stimulate bacterial growth. Skin bacteria may favor wing feather growth through competition with harmful bacteria, or faster feather growth may facilitate bacterial growth through the accumulation of remains on the skin surrounding growing feathers.

Sexual selection theory suggests that the degree of protandry in spring migration should increase when earlier males benefit from better mating opportunities. Western European studies failed to show differences in sex-specific arrival dates for the Pied Flycatcher. However, different climatic conditions and other constraints may affect its phenology in continental Europe. Here, we present evidence that sex-related phenological changes have occurred over the past 25 years (between 1989 and 2013) in Central Europe (Ocsa Bird Ringing Station, Hungary). The spring arrival of male flycatchers shifted to earlier dates whereas female arrival showed no change, implying an increasing degree of protandry.

It is not clear at present if variation in testosterone (T) levels is associated with variation in plumage signal expression in female birds. In Iberian populations of Pied Flycatchers Ficedula hypoleuca, some females exhibit a distinctive white forehead patch similar to that found in males. Both sexes also exhibit conspicuous white patches on wings that vary greatly in size. Males show markedly larger wing patches. These patches are exhibited in social interactions. We have aimed at detecting if naturally occurring variation in T circulation is linked to the expression of forehead patch presence and folded wing white patch area in female Pied Flycatchers. There was marked variation in female plumage patches and in T levels. The area of the wing white patch but not the presence of a forehead patch in females was associated with higher circulating T levels during the incubation phase when controlling for female age and hatching success. Older females, and females suffering a reduced hatching success, also presented lower levels of T. Our study indicates that a female plumage trait that is equivalent to a sexually selected trait in males may signal T levels. Females, like males, may use plumage traits to signal their T-mediated aggressive disposition.

Bacteria have the potential to be important selective forces in the evolution of many aspects of avian biology, including nestling growth. We estimated abundances of two common gut bacterial types in birds (enterococci and Enterobacteriaceae) and their correlation with growth in tarsus length, mass and wing length of 102 nestlings (54 broods) of the Pied Flycatcher, Ficedula hypoleuca, in a population of central Spain. Chicks were weighed and measured on days 7–13 after hatching, at which ages fecal samples were obtained for detection and estimation of abundance of enterococci and Enterobacteriaceae. The loads of the two bacterial types were not correlated. Enterobacterial loads decreased from day 7 to 13, while loads of enterococci increased during the same period. On day 7, loads of Enterobacteriaceae among nest mates were similar whereas loads of enterococci were not similar. On day 13, nest mates did not have similar loads of either bacterial type. Loads of enterococci were positively correlated with body mass and wing length on day 7, but not on day 13. Tarsus growth between days 7 and 13 was negatively correlated with loads of enterococci on day 7.

One male Ficedula flycatcher, breeding in southeast Norway, was identified in the field as a putative hybrid between the Pied Flycatcher F. hypoleuca and the Collared Flycatcher F. albicollis due to the presence of a partial neck collar and other intermediate plumage traits. The male and his seven nestlings were genotyped using species-diagnostic genetic markers, along with three positive controls of both flycatcher species. The male only possessed Pied Flycatcher alleles, suggesting that it is a pure Pied Flycatcher but with rare plumage characteristics approaching those of a Collared Flycatcher. Partial neck collars are also found in other black-and-white flycatcher species; the Semi-collared Flycatcher F. semitorquata (regularly) and the Atlas Flycatcher F. speculigera (occasionally), and have also been reported to occasionally occur among the Iberian subspecies of the Pied Flycatcher (F. h. iberiae). We suggest that a (partial) neck collar may be the ancestral character state of the common ancestor of these black-and-white flycatcher species, and thus that the trait may also occasionally be expressed in populations that normally lack it. Our study demonstrates that species identification based on morphological cues may sometimes be insufficient, even in species that normally possess species-diagnostic plumage characteristics.

International audience; Glucocorticoids promote the mobilization of energy stores and they may facilitate the expression of energetically expensive functions. Early arrival on the breeding grounds in migratory species and territorial competition are energetically demanding activities that may be supported by elevated baseline glucocorticoid levels. Here, we evaluated the associations between the baseline levels of excreted corticosterone (CORT) metabolites of male Pied Flycatchers () just after arriving on their breeding area and timing of arrival, considering ornamental traits indicative of social status, like forehead patch size and black plumage coloration, as well as heat shock protein levels (HSP60). We observed a positive association of CORT metabolites with HSP60 levels, which are synthesized under several environmental challenges affecting cell homeostasis. Our data showed a negative association between arrival date and CORT metabolite levels, possibly as a result of the higher energetic demands imposed by the hard environmental conditions experienced at the time of an early arrival after migration. We observed a negative relationship of forehead patch dimensions and CORT metabolite levels, suggesting that dominance is associated with low baseline CORT metabolites. Also, males that expressed a higher degree of territorial behaviour when exposed to a playback song of a conspecific at their nest-box showed higher CORT metabolites upon arrival than males that expressed a lower degree of territorial behavior. This may indicate that elevated baseline CORT metabolite levels may facilitate an intense territorial competition in males. Thus, male–male competition may be a factor affecting observed baseline glucocorticoid levels in migratory birds.

Blood samples from 94 coal tits (Parus ater), 56 great tits (Parus major) and 219 pied flycatchers (Ficedula hypoleuca), caught between 1993 and 2002 at two localities in Lower Saxony, Germany, were examined for haemosporidian infection by parasite-specific polymerase chain reaction (PCR). A simple PCR targeting the 18 SSU rRNA gene of the parasites was used for rapid screening of the samples and generated a total infection prevalence of 20.6% (76/369): 6.8% (n = 15) of the pied flycatchers, 19.1% (n = 18) of the coal tits and 76.8% (n = 43) of the great tits were infected. The positive specimens were re-examined by a cytochrome b gene-directed nested PCR producing significantly longer DNA fragments (approx. 520 bp) that were sequenced and analysed against GenBank-deposited nucleotide sequences. In various numbers (once to 30 times), a total of 13 parasitic DNA sequences differing from 2.9 to 8.5% (13–45 nucleotides) were demonstrated in the three bird species. Due to similarities of 98–100% with GenBank entries, 11 sequences could be assigned to Plasmodium sp. and two to the genus Haemoproteus. In summary, 57 birds were infected with Plasmodium and 19 with Haemoproteus, corresponding to 15.4 and 5.1% of all birds examined, and to 75 and 25% of all birds tested positive. As the only defined species, Haemoproteus majoris was identified in 17 great tits.

We present evidence of differential maternal allocation to eggs in response to manipulated male attractiveness in the migratory pied flycatcher (Ficedula hypoleuca). We manipulated the size of a male secondary sexual trait, the white forehead patch, right after male arrival to the breeding area and before female arrival. Patch size was (1) enlarged to the maximum observed in the population, (2) reduced by 40% or (3) kept constant by painting with indelible felt markers over the natural feather patch. Male behaviour was affected by the experimental manipulation, as individuals with enlarged patches performed more approaches to the nestbox in response to song playback during the territory occupation and nest-site presentation phases. Females paired with males with reduced forehead patches laid significantly smaller eggs than those paired with males in the control and enlarged-patch treatments. Laying date and clutch size did not differ among the experimental groups. We discuss that manipulations of ornaments designed to study differential allocation at laying should reduce as well as enlarge their expression.

Coinciding with increasing spring temperatures in Europe, many migrants have advanced their arrival or passage times over the last decades. However, some species, namely long-distance migrants, could be constrained in their arrival dates due to their largely inherited migratory behaviour and thus a likely inflexibility in their response to exogenous factors. To examine this hypothesis for pied flycatchers (Ficedula hypoleuca), we tested the effects of the temperature regimes along their migration routes north of the Sahara on their arrival times in central Europe. To do so, we developed a site-independent large-scale approach based on temperature data available on the Internet. Temperature regimes along the migration routes of pied flycatchers within Europe convincingly correlate with their first arrival times. It can be concluded that the progression of spring migration in this species is strongly influenced by temperature en route. Because of the recent inconsistent climatic changes in various parts of Europe, we hypothesize that individuals migrating along different routes will be unequally affected by further climatic changes.

Physiological tools can be used to identify the sources and consequences of stressors on animals. Understanding the influences of variation in habitat quality and anthropogenic disturbance on organism condition and health may improve future management and conservation. We present results concerning variation in haemoglobin and glucose concentrations in the blood of about 14-day-old nestling Pied FlycatchersFicedula hypoleuca in central Poland over a 4-year period, 2011–2014, in a deciduous forest. The most important findings of the study are: (1) the concentration of haemoglobin and glucose of the nestlings from the same brood tended to be consistently similar, with much variation occurring among broods; (2) repeatability of haemoglobin concentration was higher than repeatability of glucose concentration; (3) mean levels of haemoglobin and glucose varied among years; (4) haemoglobin and glucose concentrations were negatively correlated; and (5) there was a positive relationship between haemoglobin levels and breeding success. All procedures were approved by the Local Ethical Committee and the State Office for Environment Protection. We thank A. Jaksa, D. Man´kowska, M. Janiszewska and J. Białek for their help and consent in conducting research in the areas under their administration. The study was founded by a grant from the Polish Ministry of Science and Higher Education No. N N304 045136 and University of Ło´dz´ (No. 506/829). We are obliged to P. Procter for linguistic consultation. We thank both reviewers for their valuable and constructive comments.