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effects of long-acting testosterone administration on testes in free living pied flycatchers ficedula hypoleuca.male pied flycatchers ficedula hypoleuca given injections of long-acting testosterone, when in full breeding condition, maintained spermatogenesis. in males given vehicle only and in untreated males the testes collapsed at the time of hatching of the brood. the number and secretory activity of the leydig cells, as indicated by enzymic activities, were markedly lowered after testosterone administration. the results make it unlikely that testosterone is responsible for testicular regression in thi ...1979583410
the development of migratory orientation mechanisms.recent experimental studies (since ca. 1985) on the ontogeny of orientation mechanisms in migratory birds are reviewed. the processes and interactions are synthesized into a framework that may help identify critical research questions. birds that grow up in the earth's magnetic field develop the ability to perform appropriate migratory orientation, even in the absence of any experience with relevant visual cues. in two species, large changes in direction during the course of migration seem to be ...19911838514
behavioral, hormonal, and morphological responses of free-living male pied flycatchers to estradiol treatment of their mates.a field experiment was performed implanting female pied flycatchers (ficedula hypoleuca) during the nest-building period with silastic tubes containing 17 beta-estradiol. control females were given empty silastic tubes. the pied flycatcher is a polygamous and polyterritorial bird species. during two successive breeding seasons effects on reproductive behavior and the reproductive systems of males were studied. reproductive success was not affected by the treatment. estradiol treatment of females ...20072045090
plasma prolactin concentrations in breeding pied flycatchers (ficedula hypoleuca) with an experimentally prolonged brooding period.this experiment explored the stimulatory effect of brooding newly hatched young on plasma prolactin concentration in male and female pied flycatchers, ficedula hypoleuca. by exchanging offspring between nestboxes, one group of parents was exposed to 1- to 3-day-old nestlings for 12 days. females in this group continued night-time brooding during these 12 days. the females, but not the males (who do not participate in brooding nestlings), after 6 days had higher plasma prolactin concentrations th ...19902328965
photoperiod as a modifying and limiting factor in the expression of avian circannual rhythms.in three species of birds that migrate long distances, the annual rhythms of gonadal activity, molt, and migratory restlessness (zugunruhe) persist for more than 1 year under certain constant conditions. the most important zeitgeber for these circannual rhythms is the annual cycle of photoperiod, which adjusts the overall period of circannual rhythms to exactly 1 year and also provides for the appropriate adjustment of seasonal activities to the temporal structure of the environment. this is ill ...20082519591
[formation of visual evoked potentials and development of visually guided behavior in the ficedula hypoleuca nestling].age dynamics of evoked potentials (eps) of wulst area of the dorsal hyperstriatum (functional analogue of mammalian visual cortex) was investigated in 2-7 days old nestlings. eps in response to light stimuli, with the duration and intensity imitating natural alimentary signals for 5-7 days-old nestlings, were recorded parallel with the behaviour. it was found that the development of the visual system in precocious nestlings became completed in postembryonal ontogenesis. the most essential change ...20066624252
[auditory evoked potentials and acoustically-directed behavior of nestlings].characteristics of auditory evoked potentials (ep) were studied in 1.5 to 7.5 days old pied flycatchers nestlings (ficedula hypoleuca) with chronically implanted electrodes in the field l (analogue of the mammal's auditory cortex). eps simultaneously with behaviour were recorded in nestlings under conditions similar to natural, in response to "feeding" calls and pure tones of different frequency and intensity. it was found that ep generation thresholds do not depend on the sum total of factors w ...20067113453
endocrine correlates of brood size in adult pied flycatchers, ficedula hypoleuca. 19827200923
seasonal changes in the activity of the thyroid glands and its interaction with testicular function in the pied flycatcher ficedula hypoleuca. 19807390137
territorial aggressiveness and its relation to the endocrine system in the pied flycatcher.behavioral and endocrine responses were studied following simulated territorial intrusions performed at two different stages in the breeding cycle (pre-nest-building and nestling period) of the pied flycatcher (ficedula hypoleuca). only 45% of the unpaired territorial males from the pre-nest-building period defended their territories by attacking the decoy. after the experimental intrusion unpaired males attacking the decoy had significantly higher plasma testosterone levels than nonattacking un ...19938454165
maternal effort mediates the prevalence of trypanosomes in the offspring of a passerine bird.the relationships between parental effort, offspring growth, and offspring blood parasitemias are poorly known. we examined the effect of parental effort on offspring size and prevalence of trypanosomes in peripheral blood of nestling pied flycatchers ficedula hypoleuca aged 13 days. trypanosome infections were likely to be shared by siblings, indicating the role of a common environment and/or shared genes in the susceptibility to infection. broods infected by trypanosomes had reduced growth, bu ...19968650160
neighborhood effects in bird distributions, navarre, spainthis study examines the role of neighborhood effects in the spatial distributions of selected bird species in navarre, spain. we employed a geographic information system (gis) to organize the data on bird distributions and relevant environmental variables and to analyze their spatial patterns. three bird species were selected for analysis: the european honey-buzzard (pernis apivorus), the eurasian hobby (falco subbuteo), and the european pied flycatcher (ficedula hypoleuca). selected environment ...19968703105
new microsatellites from the pied flycatcher ficedula hypoleuca and the swallow hirundo rustica genomes. 19968931360
melatonin is crucial for the migratory orientation of pied flycatchers (ficedula hypoleuca pallas)after pinealectomy, young pied flycatchers tested in the geomagnetic field have been found to be disoriented. in order to examine the possible role of the pineal hormone melatonin, handraised flycatchers were pinealectomized (px) at the age of 8 weeks. from the day of operation onward, the pxmel group received 100 µg of melatonin every evening 1 h before darkness, the pxsol group was injected with the solvent only, and the px group was untreated. unoperated birds served as controls. during ...19949317752
experimentally reduced paternity affects paternal effort and reproductive success in pied flycatchersthe question of whether, and how, male birds should change their parental effort in response to reduced paternity is a controversial issue among behavioural ecologists. we report a study on pied flycatchers, ficedula hypoleuca, in which paternity was manipulated through experimentally induced mate switching during the female's fertile period. the paternity of care-giving males ranged from 0 to 100% of the brood. the number of parental males per nest varied between zero and two, and the amount of ...19989480700
behavioural and hormonal responses of the pied flycatcher to environmental stressors.i investigated the effects of high plasma levels of corticosterone in male pied flycatchers, ficedula hypoleuca, during the period of territorial establishment and the nestling period. in a second experiment males were exposed to a territorial intruder, a great spotted woodpecker model and a weasel model during the nest-building and nestling periods and their behavioural and hormonal reactions studied. males were also exposed to handling stress (hormonal study) during these periods. during the p ...19989641986
neuroanatomical distribution and variations across the reproductive cycle of aromatase activity and aromatase-immunoreactive cells in the pied flycatcher (ficedula hypoleuca).the anatomical distribution and seasonal variations in aromatase activity and in the number of aromatase-immunoreactive cells were studied in the brain of free-living male pied flycatchers (ficedula hypoleuca). a high aromatase activity was detected in the telencephalon and diencephalon but low to negligible levels were present in the optic lobes, cerebellum, and brain stem. in the diencephalon, most aromatase-immunoreactive cells were confined to three nuclei implicated in the control of reprod ...19989698501
influence of heavy metal exposure during different phases of the ontogeny on the development of pied flycatchers, ficedula hypoleuca, in natural populations. 19989776781
territorial behaviour and hormones of pied flycatchers in optimal and suboptimal habitats.since pied flycatchers, ficedula hypoleuca, breed at higher densities in deciduous forests than in coniferous forests, competition for territories is likely to be greater in the former, optimal habitat. i tested the hypotheses that males in a deciduous forest defend their newly established territories more intensely and have higher plasma levels of testosterone than males in a suboptimal coniferous forest. in the deciduous forest, breeding density was higher, egg laying started earlier and more ...19989790691
modelling migration: the clock-and-compass model can explain the distribution of ringing recoveries.the aim of the present study was to test whether the directional distributions found in ringing recoveries could be explained if night-migrating passerines use only a simple clock-and-compass strategy during autumn migration. i developed a mathematical model that predicts the expected directional distributions as a function of distance covered by birds using a clock-and-compass strategy. the predictions were compared with data from natural migration: all ringing recoveries of pied flycatchers, f ...19989790701
sexual differences in the control of postnuptial moult in the pied flycatcher.in this experimental study, the postnuptial moult in the pied flycatcher, ficedula hypoleuca, was studied in relation to the timing of the breeding cycle. by exchanging clutches with different laying dates, i either delayed or advanced the breeding cycle. at fledging time, the majority of delayed females started moulting while still feeding the nestlings, while advanced females only rarely did so. the moult of delayed females had also progressed further than that of females in control and advanc ...19989819339
mate choice copying versus preference for actively displaying males by female pied flycatchers.should a female copy the mate choice of other females? a female may rank a mated male higher in quality than an unmated male because the former has demonstrated that he is able to attract a female. however, a prospecting female may also avoid a mated male because of the risk that she has to compete with the male's initial mate over access to copulations, breeding resources and male parental care. we studied the mate choice of female pied flycatchers ficedula hypoleuca, in aviaries divided into t ...199910196059
orientation in pied flycatchers: the relative importance of magnetic and visual information at dusk.we investigated the orientation of juvenile pied flycatchers, ficedula hypoleuca, during autumn migration in south sweden using orientation cage experiments, to study the relative importance of visual and magnetic information at sunset. we performed cage tests under 12 experimental conditions that manipulated the geomagnetic and visual sunset cues available for orientation: natural clear skies in the local or a vertical magnetic field; simulated total overcast in the local or a vertical magnetic ...199910208717
distribution of aromatase activity in the brain and peripheral tissues of passerine and nonpasserine avian species.many behavioral effects of testosterone on hypothalamic and limbic brain areas are mediated by the action, at the cellular level, of estrogens derived from local testosterone aromatization. aromatase activity and cells containing the aromatase protein and mrna have accordingly been identified in the brain areas involved in the control of behavior. the presence of an unusually high level of aromatase activity has been detected in the telencephalon of one songbird species, the zebra finch (taeniop ...200010620422
developmental changes in 7-ethoxyresorufin-o-deethylase (erod) and delta-aminolevulinic acid dehydratase (ala-d) activities in three passerines.in this study, we report changes in 7-ethoxyresorufin-o-deethylase (erod) and delta-aminolevulinic acid dehydratase (ala-d) enzyme activities during development of three wild passerine bird species: pied flycather (ficedula hypoleuca), great tit (parus major) and blue tit (p. caeruleus). activities were determined from late embryos, newly hatched, 1-week-old and 15-day-old nestlings and adult birds. erod activity from hepatic microsomes and ala-d activity from liver tissue and erythrocytes were ...199910622436
discrepancies in population differentiation at microsatellites, mitochondrial dna and plumage colour in the pied flycatcher--inferring evolutionary processes.genetic differentiation between three populations of the pied flycatcher ficedula hypoleuca (norway, czech republic and spain, respectively) was investigated at microsatellite loci and mitochondrial dna (mtdna) sequences and compared with the pattern of differentiation of male plumage colour. the czech population lives sympatrically with the closely related collared flycatcher (f. albicollis) whereas the other two are allopatric. allopatric populations are on average more conspicuously coloured ...200010964233
female pied flycatchers fail to respond to variations in nest humidity.we examined the possibility that a cavity-nesting passerine, the pied flycatcher (ficedula hypoleuca), can modify the permeability of its eggs to water vapor facultatively in response to variations in nest humidity (p(n)). we found no significant relationship between the water-vapor conductance (g(e)) of flycatcher eggs and p(n). in addition, incubating female flycatchers failed to change their patterns of incubation when we modified p(n) experimentally. these data, coupled with large variations ...200010996823
a mathematical expectation model for bird navigation based on the clock-and-compass strategy.we present here a mathematical formula for the directional distribution of migratory birds if they use a vector navigation/clock-and-compass strategy to find their winter quarters. it is based on mathematical expectation theory and shows that a simple parabola can describe the expected geographical spread of clock-and-compass birds as a function of migratory distance. predictions based on this model are then tested against all same autumn ringing recoveries of first-season pied flycatchers, fice ...200011034834
[postnatal developmental stages in the retinal photoreceptor cells of ficedula hypoleuca]. 200811075465
[increasing selectivity of defense behavior during development of pied flycatcher nestlings].the development of defense reaction was studied in the wildlife and experimentally in 7 broods of altricial pied flycatcher (ficedula hypoleuca) nestlings. field studies demonstrated that passive-defense response first appeared on the 4th day of the nest life. it developed from the cessation of begging in young relatively satiated nestlings to characteristic freezing response independent of the level of feeding motivation in older nestlings. older nestlings also acquire the defense reaction in r ...201411253388
speciation, introgressive hybridization and nonlinear rate of molecular evolution in flycatchers.evolutionary history of muscicapidae flycatchers is inferred from nuclear and mitochondrial dna (mtdna) sequence comparisons and population genetic analysis of nuclear and mtdna markers. phylogenetic reconstruction based on sequences from the two genomes yielded similar trees with respect to the order at which the species split off. however, the genetic distances fitted a nonlinear, polynomial model reflecting diminishing divergence rate of the mtdna sequences compared to the nuclear dna sequenc ...200111298984
adjustment to climate change is constrained by arrival date in a long-distance migrant bird.spring temperatures in temperate regions have increased over the past 20 years, and many organisms have responded to this increase by advancing the date of their growth and reproduction. here we show that adaptation to climate change in a long-distance migrant is constrained by the timing of its migratory journey. for long-distance migrants climate change may advance the phenology of their breeding areas, but the timing of some species' spring migration relies on endogenous rhythms that are not ...200111357129
possible roles for corticosterone and critical size in the fledging of nestling pied flycatchers.our study was designed to see whether corticosterone (b) rises abruptly in the blood of nestling pied flycatchers (ficedula hypoleuca) at the time they fledge, as reported recently for kestrels, and if so, why. we measured the growth and blood levels of b and selected nutrients of nestlings in broods of five, seven, and nine chicks during 1998 and 1999. in half of the broods, we clipped selected wing and tail feathers of both parents with the intention of making it more difficult for them to pro ...201311517450
migrating songbirds tested in computer-controlled emlen funnels use stellar cues for a time-independent compass.this paper investigates how young pied flycatchers, ficedula hypoleuca, and blackcaps, sylvia atricapilla, interpret and use celestial cues. in order to record these data, we developed a computer-controlled version of the emlen funnel, which enabled us to make detailed temporal analyses. first, we showed that the birds use a star compass. then, we tested the birds under a stationary planetarium sky, which simulated the star pattern of the local sky at 02:35 h for 11 consecutive hours of the nigh ...200111807103
protein loss during long-distance migratory flight in passerine birds: adaptation and constraint.during long-distance flights, birds catabolize not only fat but also protein. because there is no storage form of protein, protein catabolism entails a structural or functional loss. in this study, we investigated which organs were most reduced in lean mass during different phases of fat store loss and whether protein loss can be regarded as adaptive or as a constraint. body and organ composition were analysed both during the autumn migration over continental europe (sample from switzerland) and ...200211907058
single-nucleotide polymorphism characterization in species with limited available sequence information: high nucleotide diversity revealed in the avian genome.as a case study for single-nucleotide polymorphism (snp) identification in species for which little or no sequence information is available, we investigated several approaches to identifying snps in two passerine bird species: pied and collared flycatchers (ficedula hypoleuca and f. albicollis). all approaches were successful in identifying sequence polymorphism and over 50 candidate snps per species were identified from approximately 9.1 kb of sequence. in addition, 17 sites were identified in ...200211918793
mate choice and imprinting in birds studied by cross-fostering in the wild.sexual-selection theories generally assume that mating preferences are heritable traits. however, there is substantial evidence that the rearing environment may be important for the development of mating preferences, indicating that they may be learnt, or modified by experience. the relative importance of such sexual imprinting across species remains largely unexplored. here, we report results of a large-scale cross-fostering experiment in the wild in which nestling birds were raised by parents ...200212137574
gender and viability selection on morphology in fledgling pied flycatchers.until recently, analyses of gender-dependent differences in viability selection and the ontogeny of sexual size dimorphism have been plagued by difficulties in determining the sex of nestling birds on the basis of morphology. recently, this problem was overcome using molecular sex identification to report for the first time body-size-mediated antagonistic selection on the viability of male and female collared flycatchers. we used molecular sex identification to analyse natural selection on fledg ...200212144654
positive fitness consequences of interspecific interaction with a potential competitor.the coexistence of species sharing mutual resources is usually thought to be limited by negative processes such as interspecific competition. this is because an overlap in resource use leads to negative fitness consequences, and traits favouring avoidance of potential competitors, for example in habitat selection, are therefore selected for. however, species interactions are acknowledged to vary from negative (competition) to mutualism, although empirical evidence for positive interspecific inte ...200212184832
impact of busy roads on breeding success in pied flycatchers ficedula hypoleuca.the impact of dense traffic on the breeding success in pied flycatchers (ficedula hypoleuca) was studied using roadside nest-boxes. nest site selection and breeding success of flycatchers were observed in relation to the distance from the road. the number of occupied territories was no higher closer to the road than it was deeper inside the forest. the distance to the road had no effect on the laying date, clutch size, or brood size. however, nests closer to the road were more likely to fail at ...200312447577
[wulst neurons in the youngs of pied flycatcher ficedula hypoleuca at previsual stage of development]. 200612625063
stress, immunocompetence and leukocyte profiles of pied flycatchers in relation to brood size manipulation.the two main trade-offs considered determining reproductive patterns in iteroparous organisms are the one between current and future reproduction, and the one between the number and quality of offspring. recently, it has been suggested that these trade-offs may be mediated by stress-induced reduction in immunocompetence. to test the hypothesis that stress reduces immune function, we investigated the effects of brood size manipulation on stress hormone levels, leukocyte profiles and immune respon ...200312695901
[heterochronic retina development in pied flycatcher ficedula hypoleuca]. 200814983688
flycatcher song in allopatry and sympatry--convergence, divergence and reinforcement.the theory of reinforcement predicts that natural selection against the production of unfit hybrids favours traits that increase assortative mating. whether culturally inherited traits, such as bird song, can increase assortative mating by reinforcement is largely unknown. we compared songs of pied (ficedula hypoleuca) and collared flycatchers (f. albicollis) from two hybrid zones of different ages with songs from allopatric populations. previously, a character divergence in male plumage traits ...200415009256
territorial aggression, circulating levels of testosterone, and brain aromatase activity in free-living pied flycatchers.testosterone (t) is a critical endocrine factor for the activation of many aspects of reproductive behavior in vertebrates. castration completely eliminates the display of aggressive and sexual behaviors that are restored to intact level by a treatment with exogenous t. there is usually a tight correlation between the temporal changes in plasma t and the frequency of reproductive behaviors during the annual cycle. in contrast, individual levels of behavioral activity are often not related to pla ...200415053938
trade-offs between sexual advertisement and immune function in the pied flycatcher (ficedula hypoleuca).good genes models of sexual selection assume that sexual advertisement is costly and thus the level of advertisement honestly reveals heritable viability. recently it has been suggested that an important cost of sexual advertisement might be impairment of the functioning of the immune system. in this field experiment we investigated the possible trade-offs between immune function and sexual advertisement by manipulating both mating effort and activity of immune defence in male pied flycatchers. ...200415058434
empty nests in the great tit (parus major) and the pied flycatcher (ficedula hypoleuca) in a polluted area.great tits (parus major) are sometimes found to incubate in their nests even though the nests contain no eggs. this phenomenon has been observed in different parts of europe (sweden, finland, uk, netherlands, germany) and it has become more common during the 1980s. we analysed the occurrence of empty nests in p. major and in pied flycatcher (ficedula hypoleuca) in sw finland from 6-year data collected in a polluted area around a copper smelter which emits large quantities of sulphuric oxides and ...200015092901
degradation of song in a species using nesting holes: the pied flycatcher ficedula hypoleuca.the habitat, but also the nest hole of a hole-nesting species, will degrade the song during transmission. we investigated how the sounds degrade in a sound transmission experiment with the song of the pied flycatcher ficedula hypoleuca (muscicapidae). ten different song elements were transmitted to microphones placed inside and outside a nest box. on average, song degradation was much greater inside than outside the nest boxes, especially with respect to excess attenuation and blurring of the so ...200415258637
contrasting patterns of polymorphism and divergence on the z chromosome and autosomes in two ficedula flycatcher species.in geographic areas where pied and collared flycatchers (ficedula hypoleuca and f. albicollis) breed in sympatry, hybridization occurs, leading to gene flow (introgression) between the two recently diverged species. notably, while such introgression is observable at autosomal loci it is apparently absent at the z chromosome, suggesting an important role for genes on the z chromosome in creating reproductive isolation during speciation. to further understand the role of z-linked loci in the forma ...200515956661
pollution-related changes in diets of two insectivorous passerines.insectivorous birds living in polluted areas are not only exposed to pollutants but they may also be affected by changes in their invertebrate food. the populations of many invertebrate species are affected by environmental pollution and such changes may lead to differences in the diet of insectivorous birds. we examined nestling food quality (invertebrate composition and heavy metal levels) and breeding performance of two cavity-nesting passerines, the great tit, parus major, and the pied flyca ...200516044352
nestling testosterone is associated with begging behaviour and fledging success in the pied flycatcher, ficedula hypoleuca.animal signals are hypothesized to be costly in order to honestly reflect individual quality. offspring solicitation signals given by nestling birds are thought to have evolved to advertise either need or individual quality. we tested the potential role of testosterone (t) in controlling the intensity of these signals by measuring begging behaviour as: (i) duration of the begging display and (ii) maximum height of the begging stretch, and by sampling endogenous t levels in nestling blood. we tes ...200616519237
negatively condition dependent predation cost of a positively condition dependent sexual signalling.predation is considered as an important factor constraining the expression of sexual signals. nevertheless, direct quantitative evidence for predation provoking significant viability costs on individuals signalling at high rates is scarce. moreover, it is unclear whether high rate signallers are able to balance presumably increased predation costs. we examined whether a condition dependent audible sexual signal, drumming, makes hygrolycosa rubrofasciata male spiders more prone to predation by pi ...200616599939
climate change and population declines in a long-distance migratory bird.phenological responses to climate change differ across trophic levels, which may lead to birds failing to breed at the time of maximal food abundance. here we investigate the population consequences of such mistiming in the migratory pied flycatcher, ficedula hypoleuca. in a comparison of nine dutch populations, we find that populations have declined by about 90% over the past two decades in areas where the food for provisioning nestlings peaks early in the season and the birds are currently mis ...200616672969
polygyny and its fitness consequences for primary and secondary female pied flycatchers.in polygynous species with biparental care, the amount of paternal support often varies considerably. in the pied flycatcher (ficedula hypoleuca), females mated with monogamous males receive more male assistance during the nestling phase than females mated with bigynous males, as the latter have to share their mates with another female. bigynous males, however, give more support to their primary broods than to their secondary broods. using a long-term dataset (31 years), the present study reveal ...200616769641
song similarity predicts hybridization in flycatchers.given that population divergence in sexual signals is an important prerequisite for reproductive isolation, a key prediction is that cases of signal convergence should lead to hybridization. however, empirical studies that quantitatively demonstrate links between phenotypic characters of individuals and their likelihood to hybridize are rare. here we show that song convergence between sympatric pied (ficedula hypoleuca) and collared flycatchers (f. albicollis) influence social and sexual interac ...200616780521
environmental pollution affects genetic diversity in wild bird populations.many common environmental pollutants, together with nuclear radiation, are recognized as genotoxic. there is, however, very little information on pollution-related genetic effects on free-living animal populations, especially in terrestrial ecosystems. we investigated whether genetic diversity in two small insectivorous passerines, the great tit (parus major) and the pied flycatcher (ficedula hypoleuca), was changed near point sources of heavy metals (two copper smelters) or radioactive isotopes ...200616807076
transgenerational priming of immunity: maternal exposure to a bacterial antigen enhances offspring humoral immunity.young vertebrates have limited capacity to synthesize antibodies and are dependent on the protection of maternally transmitted antibodies for humoral disease resistance early in life. however, mothers may enhance fitness by priming their offspring's immune systems to elevate disease resistance. transgenerational induced defences have been documented in plants and invertebrates, but maternal priming of offspring immunity in vertebrates has been essentially neglected. to test the ability of mother ...200616959648
cross-fostering reveals seasonal changes in the relative fitness of two competing species of flycatchers.spatial and temporal heterogeneity in relative fitness of competing species is a key factor affecting the structure of communities. however, it is not intuitive why species that are ecologically similar should differ in their response to environmental changes. here we show that two sympatric flycatchers differ in reproductive strategy and in sensitivity to harsh environment. the fitness of collared flycatchers (ficedula albicollis), which are dominant in interference competition, is more sensiti ...200517148130
environmental pollution has sex-dependent effects on local survival.environmental pollutants cause a potential hazard for survival in free-living animal populations. we modelled local survival (including emigration) by using individual mark-recapture histories of males and females in a population of a small insectivorous passerine bird, the pied flycatcher (ficedula hypoleuca) living around a point source of heavy metals (copper smelter). local survival of f. hypoleuca females did not differ between polluted and unpolluted environments. males, however, showed a ...200617148387
egg colour reflects the amount of yolk maternal antibodies and fledging success in a songbird.blue-green colours in avian eggs have been proposed as post-mating signals of female phenotypic quality to their mates. egg colour may not only indicate female value, but also the quality of the eggs themselves and of resulting offspring. to date, there has been no demonstration of an association between egg colour and egg or offspring immune quality. we here show that the intensity of blue-green colour of pied flycatcher ficedula hypoleuca eggs reflects the amount of maternal antibodies in the ...200617148396
[development of hearing sensitivity and formation of acoustically driven defensive behavior of ficedula hypoleuca]. 200717214298
maternal androgens in the pied flycatcher: timing of breeding and within-female consistency.maternal hormones can have substantial phenotypic effects in the progeny of many vertebrates. it has been proposed that mothers adaptively adjust hormone levels experienced by particular young to optimize their reproductive output. in birds, systematic variation in egg hormone levels has been related to different female reproductive strategies. because in many bird species prospects of the offspring change seasonally and with brood number, strategic adjustment of yolk androgen levels would be ex ...200717216215
does migration of hybrids contribute to post-zygotic isolation in flycatchers?in the face of hybridization, species integrity can only be maintained through post-zygotic isolating barriers (pibs). pibs need not only be intrinsic (i.e. hybrid inviability and sterility caused by developmental incompatibilities), but also can be extrinsic due to the hybrid's intermediate phenotype falling between the parental niches. for example, in migratory species, hybrid fitness might be reduced as a result of intermediate migration pathways and reaching suboptimal wintering grounds. her ...200717254995
species divergence in offspring begging intensity: difference in need or manipulation of parents?conflicts over the delivery and sharing of food among family members are expected to lead to evolution of exaggerated offspring begging for food. coevolution between offspring begging intensity and parent response depends on the genetic architecture of the traits involved. given a genetic correlation between offspring begging intensity and parental response, there may be fast and arbitrary divergence in these behaviours between populations. however, there is limited knowledge about the genetic b ...200717264061
blood metabolite levels in normal and handicapped pied flycatchers rearing broods of different sizes.we measured levels of select metabolites (glucose, triglycerides, free fatty acids, glycerol, uric acid) and corticosterone in the blood plasma of adult pied flycatchers ficedula hypoleuca while they were rearing broods whose sizes were modified experimentally. we also made it more difficult than normal for some pairs of birds to forage by removing certain wing and tail feathers (handicapping them). both procedures have been shown previously to change parental workload. we did this in order to d ...200717267253
prehatching maternal investment and offspring immunity in the pied flycatcher (ficedula hypoleuca).maternal investment in offspring immunity via egg quality may be an adaptive evolutionary strategy shaped by natural selection. we investigated how maternal investment in eggs can influence offspring immunity by conducting two experiments. first, we manipulated foraging performance of the mothers before egg laying by attaching a small weight to their back feathers. during the nestling period, we investigated offspring total antibody production at the age of 7 days and after antibody challenge, a ...200717305837
characterization of the first growth hormone gene sequence for a passerine bird--the pied flycatcher (ficedula hypoleuca).while the growth hormone (gh) gene has been characterized in a broad range of vertebrates, surprisingly little is known about this gene in birds. in order to extend knowledge of the gh gene in avian species and non-domestic species, the pied flycatcher (ficedula hypoleuca) gh gene has been sequenced in this study. the overall average pairwise sequence divergence level was 0.08 among all available avian sequences and 0.27 among other taxa. however, the overall genetic organization of the gene is ...200617381040
birds prefer to breed in sites with low radioactivity in chernobyl.low-level radioactive contamination may affect choice of breeding site and life-history decisions if (i) radioactivity directly affects body condition or (ii) it affects resource abundance that then secondarily influences reproductive decisions. we tested the effects of radioactive contamination on nest-site choice and reproduction in a community of hole nesting birds by putting up nest boxes in areas differing in levels of background radiation. great tit parus major and pied flycatcher ficedula ...200717389224
experimental evidence for species-specific habitat preferences in two flycatcher species in their hybrid zone.hybrid zones are often found in areas where the environmental characteristics of native habitat of both parental species meet. one of the plausible mechanisms that maintain species distinctiveness, or limit hybridization, is the existence of local species-specific preferences for the natal habitat type. we evaluated this hypothesis for two passerine bird species, the pied ficedula hypoleuca and collared flycatcher f. albicollis, in their narrow hybrid zone in central europe. both species have qu ...200717534589
oxidative stress in pied flycatcher (ficedula hypoleuca) nestlings from metal contaminated environments in northern sweden.metals have been shown to induce oxidative stress in animals. one of the most metal polluted terrestrial environments in sweden is the surroundings of a sulfide ore smelter plant located in the northern part of the country. pied flycatcher nestlings (ficedula hypoleuca) that grew up close to the industry had accumulated amounts of arsenic, cadmium, mercury, lead, iron and zinc in their liver tissue. the aim of this study was to investigate if pied flycatcher nestlings in the pollution gradient o ...200717631289
nestling testosterone controls begging behaviour in the pied flycatcher, ficedula hypoleuca.begging signals and endogenous testosterone (t) levels of young birds have been shown to be positively correlated. if t is causally involved in controlling the level of begging effort, an endocrine control mechanism could explain the evolution of begging as a costly signal reflecting need. we tested experimentally whether elevated circulating t levels enhanced begging behaviour in nestling pied flycatchers, ficedula hypoleuca. a pilot study confirmed that nestling t levels could be elevated with ...200717692851
[structural and functional aspects of variation of the breeding plumage ornamentation in the male pied flycatcher ficedula hypoleuca (aves: passeriformes)].inter- and intraindividual variation of the breeding plumage ornamentation in male pied flycatcher ficedula hypoleuca from the moscow province population (55 degrees 44' n 36 degrees 51' e) was studied using long-term data (1996-2005). eumelanin prevailing colour type (ct) scored according to the seven-step dorst scale (dorst, 1936), age, and reproductive status during the current breeding season were analyzed as potential sources of variation of the white ornamentation on the forehead, the wing ...200717944112
corticosterone metabolites in blue tit and pied flycatcher droppings: effects of brood size, ectoparasites and temperature.the hypothalamic-pituitary-adrenal (hpa) axis of birds induces the secretion of corticosterone (cort) as a response to different ecological variables. in this study we tested experimentally if manipulations of brood size or ectoparasitism led to subsequent differences in the concentration of excreted cort metabolites of adult and nestling blue tits (cyanistes caeruleus). no significant effect of the manipulation of brood size was detected in adults or nestlings. no significant effect of ectopara ...200818062967
natural and sexual selection against hybrid flycatchers.while sexual selection is generally assumed to quickly cause or strengthen prezygotic barriers between sister species, its role in causing postzygotic isolation, through the unattractiveness of intermediate hybrids, is less often examined. combining 24 years of pedigree data and recently developed species-specific molecular markers from collared (ficedula albicollis) and pied (ficedula hypoleuca) flycatchers and their hybrids, we were able to quantify all key components of fitness. to disentangl ...200818211878
pre-laying nutrition mediates maternal effects on offspring immune capacity and growth in the pied flycatcher.we have aimed at detecting prelaying maternal effects on nestling antibody defences and growth through experimental food supplementation of female pied flycatchers ficedula hypoleuca and subsequent exchange of whole clutches with control nests. the levels of immunoglobulins and the mass and size of chicks at 12 days of age were ascertained. this is the first study controlling for maternal incubation effects by exchanging eggs rather than nestlings. our prediction is that the females' availabilit ...200818369666
the effects of sex, age and breeding success on breeding dispersal of pied flycatchers along a pollution gradient.we modelled breeding dispersal of an insectivorous bird, the pied flycatcher (ficedula hypoleuca) around a point source of heavy metals (a copper smelter). we tested for the effects of sex, age, breeding success and environmental pollution on breeding dispersal distances of f. hypoleuca females and males. unlike many earlier studies on breeding dispersal, we took into account distance-dependent sampling bias by including in our model the recapture probabilities at different distances from the si ...200818543001
selection on sperm morphology under relaxed sperm competition in a wild passerine bird.theories regarding the role of sexual selection on the evolution of sperm traits are based on an association between pre-copulatory (e.g. female preference) and post-copulatory (e.g. ejaculate quality) male reproductive traits. in tests of these hypotheses, sperm morphology has rarely been used, despite its high heritability and intra-individual consistency. we found evidence of selection for longer sperm through positive phenotypic associations between sperm size and the two major female prefer ...200918986959
indirect cues of nest predation risk and avian reproductive decisions.current life-history theory predicts that increased mortality at early stages of life leads to reduced initial investment (e.g. clutch size) but increased subsequent investment during the reproduction attempt. in a field experiment, migratory pied flycatchers ficedula hypoleuca perceived differences in mammalian nest predation risk and altered their reproductive strategies in two respects. first, birds avoided nest sites manipulated to reflect the presence of a predator. second, birds breeding i ...200919126533
effects of reduced lead deposition on pied flycatcher (ficedula hypoleuca) nestlings: tracing exposure routes using stable lead isotopes.to what extent the lead burden of birds living in strongly contaminated ecosystems is responding to decreased atmospheric lead deposition is not well known. in this study, we measured lead concentrations and stable lead isotope ratios (206pb/207pb and 208pb/207pb) in liver and feces from pied flycatcher nestlings (ficedula hypoleuca) along a 90 km pollution gradient from the rönnskär smelter in northern sweden. changes in lead concentration in the birds from 1984 to 2006 were used for assessing ...200919209608
local survival of pied flycatcher males and females in a pollution gradient of a cu smelter.survival is one of the most central population measures when the effects of the pollution are studied in natural bird populations. however, only few studies have actually measured rigorous survival estimates on adult birds. in recent years there has been a methodological advance in survival analyses by mark-recapture models. we modelled local survival (including mortality and emigration) with the program mark in a population of a small insectivorous passerine bird, the pied flycatcher (ficedula ...200919232803
isospora hypoleucae sp. n. (apicomplexa: eimeriidae), a new coccidian parasite found in the pied flycatcher (ficedula hypoleuca).a new coccidia species is reported from the natural population of pied flycatcher (ficedula hypoleuca) in northern germany. sporulated oocysts were found in faeces from 6 of 8 sampled adults. the spherical oocysts of the new isospora species have a brownish, smooth, bi-layered wall. average size of sporulated oocysts was 19.4 x 19.3 microm (17.5-22.8 microm x 17.5-22.8 microm ) with a shape index (length/width) of 1.0. the sporulated oocysts have no micropyle or residuum, but enclose several sma ...200919450377
development of stress response in nestling pied flycatchers.birds respond to unpredictable events by secreting corticosterone, which induces various responses to cope with stressful situations. however, the evidence is still elusive whether altricial nestlings perceive and respond to external stressors. we investigated the development of adrenocortical stress response to handling-related stressor in nestlings of a small passerine bird, the pied flycatcher (ficedula hypoleuca). nestlings were held in isolation from their parents during the experiment to e ...200919506887
life-history divergence facilitates regional coexistence of competing ficedula flycatchers.regional coexistence of ecologically similar species is facilitated when fluctuations in environmental conditions favor different species at different times or places. however, why species with similar ecology should vary in their response to environmental change is unclear. in this study, we explore the role of a life-history divergence in causing changes in relative fitness across environmental conditions experienced by populations of two closely related ficedula flycatchers on the baltic isla ...200919694142
polluted environment and cold weather induce laying gaps in great tit and pied flycatcher.we studied the occurrence of laying gaps in free-living populations of the pied flycatcher, ficedula hypoleuca, and the great tit, parus major, in a pollution gradient of a copper smelter in south-west finland. laying gaps were 2.8 times more common in f. hypoleuca than in p. major. the probability of laying gaps was highest in the heavily polluted zone and lowest in the unpolluted zone for both bird species. cold weather at the time of laying increased the number of laying gaps in both species, ...201019784674
geographic patterns of genetic differentiation and plumage colour variation are different in the pied flycatcher (ficedula hypoleuca).the pied flycatcher is one of the most phenotypically variable bird species in europe. the geographic variation in phenotypes has often been attributed to spatial variation in selection regimes that is associated with the presence or absence of the congeneric collared flycatcher. spatial variation in phenotypes could however also be generated by spatially restricted gene flow and genetic drift. we examined the genetic population structure of pied flycatchers across the breeding range and applied ...200919796331
yolk hormones have sex-specific long-term effects on behavior in the pied flycatcher (ficedula hypoleuca).the hormonal environment during early development, such as maternally derived androgens in bird eggs, shapes the development and phenotype of the offspring in ways that may have important long-term consequences for behaviour. we studied the effects of yolk androgens on multiple behavioural traits in female and male pied flycatchers (ficedula hypoleuca) by experimentally elevating androgen levels (testosterone and androstenedione) in the eggs. the birds were housed in a common-garden environment ...201019804778
the increased risk of predation enhances cooperation.theory predicts that animals in adverse conditions can decrease individual risks and increase long-term benefits by cooperating with neighbours. however, some empirical studies suggest that animals often focus on short-term benefits, which can reduce the likelihood that they will cooperate with others. in this experimental study, we tested between these two alternatives by evaluating whether increased predation risk (as a correlate of environmental adversity) enhances or diminishes the occurrenc ...201019846454
habitat selection as an antipredator behaviour in a multi-predator landscape: all enemies are not equal.1. breeding territory choice constitutes a crucial antipredator behaviour for animals that determines reproductive success and survival during the breeding season. on arrival to breeding grounds migrant prey face a multitude of 'waiting' predators already settled within the landscape. 2. we studied territory selection and reproductive investment of migrant pied flycatcher (ficedula hypoleuca) relative to breeding pygmy owls (pos) (glaucidium passerinum) and tengmalm's owls (tos) (aegolius funere ...201019912426
lead exposure and biological effects in pied flycatchers (ficedula hypoleuca) before and after the closure of a lead mine in northern sweden.mining activities affect the surrounding environment by increasing exposure to metals. in this study, metal accumulation and its effects on reproduction and health of pied flycatcher (ficedula hypoleuca) nestlings were monitored before and up to five years after a lead mine and enrichment plant closed down. the lead concentration in moss, nestling blood, liver and feces all indicated decreased lead exposure by at least 31% after closure, although only blood lead decreased significantly. although ...201020116150
flexibility of timing of avian migration to climate change masked by environmental constraints en route.during the past decades, phenology of many organisms has advanced in response to climate change [1]. earlier arrival of long-distance migrants has been reported frequently [2, 3], but advancements of arrival and breeding were not always sufficient to match phenology at other trophic levels [4]. this has led to increased selection for early breeding [5] and severe population declines [6, 7]. this inadequate response has been explained by an inflexible start of migration, governed by cues unrelate ...201020116248
ecology and genetics of speciation in ficedula flycatchers.birds have for long been popular study objects in speciation research. being easy to observe in the field, they have traditionally been particularly important in studies of behavioural and ecological factors in speciation, whereas the genetic aspects of the process have been studied in other organisms, such as drosophila. more recently, however, a stronger genetic focus has been placed on speciation research also in birds. here, we review ecological, behavioural and genetic studies on speciation ...201020163542
behavioral and physiological responses of nestling pied flycatchers to acoustic stress.the extended secretion of stress hormones in fully developed animals is known to have profound consequences. however, little is known about the effects of stress on the behavior and physiology of free-living young animals, and how such responses relate to each other. we repeatedly (during 5 consecutive days, 1 h/day) exposed the nestlings of a passerine bird, the pied flycatcher (ficedula hypoleuca), to recordings of nestling distress calls and examined their behavioral and physiological respons ...201020171225
what prevents phenological adjustment to climate change in migrant bird species? evidence against the "arrival constraint" hypothesis.phenological studies have demonstrated changes in the timing of seasonal events across multiple taxonomic groups as the climate warms. some northern european migrant bird populations, however, show little or no significant change in breeding phenology, resulting in synchrony with key food sources becoming mismatched. this phenological inertia has often been ascribed to migration constraints (i.e. arrival date at breeding grounds preventing earlier laying). this has been based primarily on resear ...201120405299
speciation in ficedula flycatchers.speciation in animals often requires that population divergence goes through three major evolutionary stages, i.e. ecological divergence, development of sexual isolation and the build-up of genetic incompatibility. there is theoretical consensus regarding favourable conditions required for speciation to reach its final and irreversible stage, but empirical tests remain rare. here, we review recent research on processes of speciation, based on studies in hybrid zones between collared (ficedula al ...201020439285
carotenoid composition of invertebrates consumed by two insectivorous bird species.dietary carotenoids are important pigments, antioxidants, and immune-stimulants for birds. despite recent interest in carotenoids in bird ecology, we know surprisingly little about the carotenoid content of invertebrates consumed by birds. we compared carotenoid (lutein, beta-carotene, and total) concentrations in invertebrates brought to nestlings by two insectivorous passerines, the great tit, parus major and the pied flycatcher, ficedula hypoleuca. we also compared carotenoid levels between e ...201020446022
effects of pollution on land snail abundance, size and diversity as resources for pied flycatcher, ficedula hypoleuca.passerine birds need extra calcium during their breeding for developing egg shells and proper growth of nestling skeleton. land snails are an important calcium source for many passerines and human-induced changes in snail populations may pose a severe problem for breeding birds. we studied from the bird's viewpoint how air pollution affects the shell mass, abundance and diversity of land snail communities along a pollution gradient of a copper smelter. we sampled remnant snail shells from the ne ...201020542535
predator proximity as a stressor in breeding flycatchers: mass loss, stress protein induction, and elevated provisioning.we investigated the physiological and behavioral consequences for prey breeding at different distances from a nesting predator. in a natural setting, pied flycatchers (ficedula hypoleuca) made territory location decisions relative to established sparrowhawk (accipiter nisus) nests. from female flycatchers attending nests at different distances from sparrowhawk nests, we measured body mass, blood stress protein (hsp60 and hsp70), and plasma immunoglobulin levels at the beginning (initial) and end ...201020583723
the risk of predation favors cooperation among breeding prey.empirical studies have shown that animals often focus on short-term benefits under conditions of predation risk, which reduces the likelihood that they will cooperate with others. however, some theoretical studies predict that animals in adverse conditions should not avoid cooperation with their neighbors since it may decrease individual risks and increase long-term benefits of reciprocal help. we experimentally tested these two alternatives to find out whether increased predation risk enhances ...201020714404
towards the simplification of mhc typing protocols: targeting classical mhc class ii genes in a passerine, the pied flycatcher ficedula hypoleuca.major histocompatibility complex (mhc) has drawn the attention of evolutionary biologists due to its importance in crucial biological processes, such as sexual selection and immune response in jawed vertebrates. however, the characterization of classical mhc genes subjected to the effects of natural selection still remains elusive in many vertebrate groups. here, we have tested the suitability of flanking intron sequences to guide the selective exploration of classical mhc genes driving the co-e ...201020815923
melanin coloration has temperature-dependent effects on breeding performance that may maintain phenotypic variation in a passerine bird.fluctuating selection pressure may maintain phenotypic variation because of different types of individuals being adapted to different environmental conditions. we show that the extensive variation in the coloration of male pied flycatchers (ficedula hypoleuca) can be maintained through differences in the reproductive success of male phenotypes under different conditions. the effects of weather conditions on the relative success of different male phenotypes varied between different phases of bree ...201020846173
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