Publications

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 ...	1979	583410
seasonal changes in the activity of the thyroid glands and its interaction with testicular function in the pied flycatcher ficedula hypoleuca.		1980	7390137
endocrine correlates of brood size in adult pied flycatchers, ficedula hypoleuca.		1982	7200923
nesting holes and food supply in relation to forest bird densities on islands and mainland.	bird densities were estimated on 41 small islands and two mainland plots at a south swedish lake both in 1976 and 1983. in the latter year, three additional plots were also censused. the ratio between combined densities of hole-nesting birds on the mainland and on islands was 3:1 both in plots without and with nest boxes. in plots with boxes combined densities of hole-nesting birds doubled compared with control plots. this increase was caused by a tenfold increase of pied flycatcher ficedula hyp ...	1985	28310792
variation of lymphoid activity in the spleen of a migratory bird, the pied flycatcher (ficedula hypoleuca; aves, passeriformes).	the size and microscopic structure of the spleen of the migratory pied flycatcher (ficedula hypoleuca) show marked changes during the reproductive cycle. upon the spring return to their northern breeding sites, the birds have a small spleen with little lymphoid activity and a poorly developed red pulp. during the breeding period the volume of red and white pulp increases, the number and distinctness of lymphoid follicles (germinal centres) in the white pulp increase, and groups of cells with int ...	1985	30016847
heritability and selection on tarsus length in the pied flycatcher (ficedula hypoleuca).	the heritability estimate (±se) for tarsus length in the pied flycatcher is 0.53 ± 0.10, based on mother-offspring regressions. the heritability is almost the same (0.50 ± 0.22) for offspring transferred to other nests and reared by foster parents, whereas there is no resemblance (0.04 ± 0.23) between the offspring and their foster mothers. hence, the nest environment does not affect parent-offspring resemblance. however, a full-sib correlation yields an estimate of the heritability twice as hig ...	1986	28556344
polyterritorialitytion in passerine birds.	in some birds, males defend two spatially separated territories and attract females to each one in turn. it has been proposed that this behaviour, referred to as polyterritoriality, allows males to conceal their marital status, thereby deceiving females into accepting polygyny against their best interests. the deception hypothesis has gained general acceptance as an explanation for polyterritoriality in birds, but until recently the empirical basis for the hypothesis rested almost entirely on st ...	1989	21227327
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 ...	1990	2328965
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 ...	1991	1838514
evolution of plumage color in male pied flycatchers (ficedula hypoleuca): evidence for female mimicry.	we present the first evidence for sexual deception by female mimicry in birds. using live, caged birds we show that territorial male pied flycatchers behave aggressively toward bright-colored males but display sexually toward female-like male intruders. we also show that the males that are fooled are those that lack recent sexual experience. all male pied flycatchers are dull-colored in winter. it is possible that young males are more constrained during the spring molt than older males since the ...	1991	28564056
plumage color is a condition-dependent sexual trait in male pied flycatchers.		1992	28568657
blood parasites and male fitness in the pied flycatcher.	in vertebrates the effect of parasites on host ecology has almost been ignored. recently the view that well-adapted parasites do not harm their hosts has been challenged and there is growing evidence that parasites do have a present-day effect on a great variety of host fitness components. the pied flycatcher is a small migratory passcrine bird. any decrease in condition caused by disease should affect its ability to cope with physical demands of migration. here we examine whether blood parasite ...	1993	28313657
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 ...	1993	8454165
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 ...	1994	9317752
heritability estimates and maternal effects on tarsus length in pied flycatchers, ficedula hypoleuca.	tarsus length has previously been shown to have an additive genetic component in some pied flycatcher populations. in addition to estimation of additive genetic variation by means of repeatability analyses at various ontogenetic stages and degrees of genetic resemblance, we explore in this paper variation among parent-offspring regressions between sexes and years, as well as the influence of hatching date, ectoparasite abundance, egg volume, and male and female condition on the tarsus length of ...	1994	28307018
ectoparasites, nest site choice and breeding success in the pied flycatcher.	it has recently been suggested that nest box studies might bias the measurement of behavioural and life-history traits, because the removal of old nests may reduce the load of ectoparasites. this experimental artefact may have notable effects on nest site choice and breeding success in cavity-breeding birds. we tested (i) if pied flycatchers ficedula hypoleuca prefer clean nest boxes and (ii) if old nest material affects the number of parasites and the breeding success of pied flycatchers. in th ...	1994	28313971
experimentally induced clutch size enlargements affect reproductive success in the pied flycatcher.	we performed a food provisioning experiment in a population of pied flycatchers ficedula hypoleuca breeding at high altitude in central spain to test if food availability before and during laying determines clutch size. food was provided to one of two pairs with the same date of initiation of nest-building (15 dyads of subsequently reproducing pairs were thus created). food provisioning began on the day of initiation of nest-building and ended on the day after the last egg was laid. although lay ...	1995	28306830
egg shell quality, clutch size and hatching success of the great tit (parus major) and the pied flycatcher (ficedula hypoleuca) in an air pollution gradient.	egg shell thickness, egg volume, clutch size and hatching success of parus major and ficedula hypoleuca were studied at 14 study sites around a copper smelter complex in harjavalta, south-west finland, in 1991-1993. in 1991-1992 unhatched eggs were collected to measure shell quality. f. hypoleuca was more susceptible to pollutants than p. major, the response of which was weaker in all aspects studied. egg shells of f. hypoleuca were about 17% thinner and eggs were about 8% smaller in volume near ...	1995	28306842
growth and mortality of nestling great tits (parus major) and pied flycatchers (ficedula hypoleuca) in a heavy metal pollution gradient.	we studied nestling growth, growth abnormalities, mortality and breeding success of two hole-nesting passerines, the great tit (parus major) and the pied fly-catcher (ficedula hypoleuca), at 14 study sites around a copper smelter complex in harjavalta, south-west finland in 1991-1993. the main pollutants in the area are heavy metals and sulphuric oxides. exposure of birds to heavy metals was shown by measuring their faecal concentrations. copper, nickel and lead contents of nestling faeces were ...	1996	28307795
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 ...	1996	8650160
new microsatellites from the pied flycatcher ficedula hypoleuca and the swallow hirundo rustica genomes.		1996	8931360
neighborhood effects in bird distributions, navarre, spain	this 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 ...	1996	8703105
large brood sizes of pied flycatcher, sparrowhawk and goshawk in peak microtine years: support for the mast depression hypothesis.	the mast depression hypothesis (mdh) proposes that cyclic population fluctuations of microtines and other herbivores are an effect of cyclic seed cropping of plants. this is because high seed crops, termed masts, are produced at the expense of chemical defence against herbivores. it has generally been assumed that bird-hunting raptors produce high numbers of offspring when microtine prey are abundant because of reduced competition from generalist predators. however, this may also be caused by hi ...	1998	28307513
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 ...	1998	9790701
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 ...	1998	9790691
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 ...	1998	9641986
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 ...	1998	9698501
trade-off between reproduction and moult - a comparison of three fennoscandian pied flycatcher populations.	organisms that reproduce at high latitudes are assumed to have evolved several adaptations to the short summer. for birds, and especially for long-distance migrants, there is a time constraint because both reproduction and moult must be completed before autumn migration. it has therefore been assumed that birds at northern latitudes must initiate their moult during reproduction more often than birds at low latitudes. to investigate how passerine birds breeding at different latitudes allocate the ...	1998	28307916
influence of heavy metal exposure during different phases of the ontogeny on the development of pied flycatchers, ficedula hypoleuca, in natural populations.		1998	9776781
heterospecific attraction and food resources in migrants' breeding patch selection in northern boreal forest.	we studied experimentally how heterospecific attraction may affect habitat selection of migrant passerine birds in finnish lapland. we manipulated the densities of resident tit species (parus spp.). in four study plots residents were removed before the arrival of the migrants in the first study year, and in four other plots their densities were increased by releasing caught individuals. in the second year the treatments of the areas were reversed, allowing paired comparisons within each plot. we ...	1998	28308463
experimentally reduced paternity affects paternal effort and reproductive success in pied flycatchers	the 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 ...	1998	9480700
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 ...	1998	9819339
environmental and genetic variation in the haematocrit of fledgling pied flycatchers ficedula hypoleuca.	we report a field study of the haematocrit of pied flycatcher (ficedula hypoleuca) nestlings when close to fledging. first a descriptive study was conducted of both fledgling and adult haematocrit over 2 years to analyse correlates of variation in this trait. then a swapping experiment was performed to see whether variation among fledglings had a measurable genetic component. average fledgling haematocrits were lower than those of their male and female parents. intraclass correlations among sibs ...	1999	28308040
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 ...	1999	10208717
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 ...	1999	10196059
maternal effects and the pervasive impact of nestling history on egg size in a passerine bird.	environmental conditions experienced during ontogeny may have important and permanent consequences for life-history traits of individuals. the aim of this work was to determine whether conditions experienced during early life, as expressed by prefledgling condition, have any bearing on the volume of eggs subsequently laid by females in a small passerine bird species, the pied flycatcher (ficedula hypoleuca). i first show a genetic influence on egg volume by dam-offspring regression. the existenc ...	1999	28565183
population divergence in sexual ornaments: the white forehead patch of norwegian pied flycatchers is small and unsexy.	models of sexual selection suggest that populations may easily diverge in male secondary sexual characters. studies of a spanish population of the pied flycatcher, ficedula hypoleuca, and a swedish population of the closely related collared flycatcher, f. albicollis, have indicated that the white forehead patch of males is a sexually selected trait. we studied the white forehead patch of male pied flycatchers (n = 487) in a norwegian population over seven years. males with large forehead patches ...	1999	28565517
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 ...	1999	10622436
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 ...	2000	11034834
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 ...	2000	10964233
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 ...	2000	10620422
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 ...	2000	15092901
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 ...	2000	10996823
interactions between hemoparasite status and female age in the primary reproductive output of pied flycatchers.	the relationship between hemoparasite infection (measured just after egg laying) and primary reproductive output (laying date, clutch size and egg volume) was studied in female pied flycatchers, ficedula hypoleuca, of different ages (2 years old vs. 4 or more years old). the hemoparasite (haemoproteus balmorali and trypanosoma spp.) prevalence increased with advancing female age. h. balmorali-infected females initiated egg laying earlier and laid larger clutches. there was no evidence that infec ...	2001	28547446
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 ...	2001	11807103
daily energy expenditure and cell-mediated immunity in pied flycatchers while feeding nestlings: interaction with moult.	ecological immunology posits a trade-off between parental effort and immunocompetence underlying the cost of reproduction. the moult-breeding overlap observed in several bird species represents a conflict in resource allocation between two energy-demanding processes. moult processes have been associated with enlargements of immune system organs. in the present study. we measured simultaneously daily energy expenditure (dee) and the t-cell-dependent immune response of pied flycatchers, ficedula h ...	2001	24577688
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 ...	2001	11298984
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 ...	2001	11357129
effects of latitude on the trade-off between reproduction and moult: a long-term study with pied flycatcher.	long-distance migratory passerine birds are generally time constrained by reproduction and moult, which need to be completed before migration. breeding and post-nuptial moult may overlap especially under time-constrained conditions (northern latitudes). here, we analysed the timing of adult moult in relation to latitude, timing of breeding and reproductive effort in pied flycatchers (ficedula hypoleuca) breeding in four widely separated populations (40-68° n). in males but not females, the propo ...	2001	28547598
are incubation costs in female pied flycatchers expressed in humoral immune responsiveness or breeding success?	although clutch size variation has been a key target for studies of avian life history theory, most empirical work has only focused on the ability of parents to raise their altricial young. in this study, we test the hypothesis that costs incurred during incubation may be an additional factor constraining clutch size in altricial birds. in the pied flycatcher (ficedula hypoleuca), we manipulated the incubation effort of the female by enlarging and reducing clutch sizes. to manipulate incubation ...	2002	28547142
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 ...	2002	12144654
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 ...	2002	11907058
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 ...	2002	12184832
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 ...	2002	12137574
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 ...	2002	11918793
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 ...	2003	12695901
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 ...	2003	12447577
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 ...	2004	15258637
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. ...	2004	15058434
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 ...	2004	15053938
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 ...	2004	15009256
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 ...	2005	17148130
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 ...	2005	16044352
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 ...	2005	15956661
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 ...	2006	17381040
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 ...	2006	17148396
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 ...	2006	17148387
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 ...	2006	16959648
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 ...	2006	16807076
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 ...	2006	16780521
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 ...	2006	16769641
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 ...	2006	16672969
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 ...	2006	16599939
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 ...	2006	16519237
[wulst neurons in the youngs of pied flycatcher ficedula hypoleuca at previsual stage of development].		2006	12625063
[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 ...	2006	6624252
[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 ...	2006	7113453
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 ...	2007	17534589
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 ...	2007	17389224
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 ...	2007	17267253
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 ...	2007	17216215
[development of hearing sensitivity and formation of acoustically driven defensive behavior of ficedula hypoleuca].		2007	17214298
[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 ...	2007	17944112
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 ...	2007	17692851
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 ...	2007	17305837
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 ...	2007	17264061
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 ...	2007	2045090
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 ...	2007	17631289
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 ...	2007	17254995
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 ...	2008	18211878
seventy new microsatellites for the pied flycatcher, ficedula hypoleuca and amplification in other passerine birds.	the pied flycatcher (ficedula hypoleuca) is a small migratory passerine bird commonly distributed across europe which has been the focus of considerable ecological and evolutionary research. here, we present details of 70 microsatellite markers for the species adding to the six which are currently available. sixty-six markers were also polymorphic in the closely related collared flycatcher (ficedula albicollis), while 54 were polymorphic in another related passerine, the bluethroat (luscinia sve ...	2008	21585917
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 ...	2008	2519591
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 ...	2008	18062967
[heterochronic retina development in pied flycatcher ficedula hypoleuca].		2008	14983688
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 ...	2008	18543001
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 ...	2008	18369666
[postnatal developmental stages in the retinal photoreceptor cells of ficedula hypoleuca].		2008	11075465
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 ...	2009	19796331
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 ...	2009	19694142
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 ...	2009	19506887