Publications

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differential contribution of demographic rate synchrony to population synchrony in barn swallows.populations of many species show temporally synchronous dynamics over some range, mostly caused by spatial autocorrelation of the environment that affects demographic rates. synchronous fluctuation of a demographic rate is a necessary, but not sufficient condition for population synchrony because population growth is differentially sensitive to variation in demographic rates. little is known about the relative effects of demographic rates to population synchrony, because it is rare that all demo ...201526179225
correction: a continent-wide migratory divide in north american breeding barn swallows (hirundo rustica). 201526171864
nest sanitation elicits egg discrimination in cuckoo hosts.nest sanitation is a nearly universal behavior in birds, while egg discrimination is a more specific adaptation that has evolved to counter brood parasitism. these two behaviors are closely related with nest sanitation being the ancestral behavior, and it has been hypothesized to constitute a preadaptation for egg discrimination. however, previous studies found little evidence to support this hypothesis. here, we conducted an empirical test of the association between nest sanitation and egg disc ...201526160343
sexual dimorphism and population differences in structural properties of barn swallow (hirundo rustica) wing and tail feathers.sexual selection and aerodynamic forces affecting structural properties of the flight feathers of birds are poorly understood. here, we compared the structural features of the innermost primary wing feather (p1) and the sexually dimorphic outermost (ta6) and monomorphic second outermost (ta5) tail feathers of barn swallows (hirundo rustica) from a romanian population to investigate how sexual selection and resistance to aerodynamic forces affect structural differences among these feathers. furth ...201526110255
a continent-wide migratory divide in north american breeding barn swallows (hirundo rustica).populations of most north american aerial insectivores have undergone steep population declines over the past 40 years but the relative importance of factors operating on breeding, wintering, or stopover sites remains unknown. we used archival light-level geolocators to track the phenology, movements and winter locations of barn swallows (hirdundo rustica; n = 27) from populations across north america to determine their migratory connectivity. we identified an east-west continental migratory div ...201526065914
assessing costs of carrying geolocators using feather corticosterone in two species of aerial insectivore.despite benefits of using light-sensitive geolocators to track animal movements and describe patterns of migratory connectivity, concerns have been raised about negative effects of these devices, particularly in small species of aerial insectivore. geolocators may act as handicaps that increase energetic expenditure, which could explain reported effects of geolocators on survival. we tested this 'energetic expenditure hypothesis' in 12 populations of tree swallows (tachycineta bicolor) and barn ...201526064659
sex allocation according to multiple sexually dimorphic traits of both parents in the barn swallow (hirundo rustica).parents should differentially invest in sons or daughters depending on the sex-specific fitness returns from male and female offspring. in species with sexually selected heritable male characters, highly ornamented fathers should overproduce sons, which will be more sexually attractive than sons of less ornamented fathers. because of genetic correlations between the sexes, females that express traits which are under selection in males should also overproduce sons. however, sex allocation strateg ...201525913917
abundance and genetic damage of barn swallows from fukushima.a number of studies have assessed or modeled the distribution of the radionuclides released by the accident at the fukushima-daiichi nuclear power plant (fdnpp). few studies however have investigated its consequences for the local biota. we tested whether exposure of barn swallow (hirundo rustica) nestlings to low dose ionizing radiation increased genetic damage to their peripheral erythrocytes. we estimated external radiation exposure by using thermoluminescent dosimeters, and by measuring radi ...201525838205
light-level geolocators reveal covariation between winter plumage molt and phenology in a trans-saharan migratory bird.contingent individual performance can depend on the environment experienced at previous life-stages. migratory birds are especially susceptible to such carry-over effects as they periodically travel between breeding ranges and 'wintering' areas where they may experience broadly different ecological conditions. however, the study of carry-over effects is hampered by the difficulty of tracking vagile organisms throughout their annual life-cycle. using information from light-level geolocators on th ...201525822115
importance of farmland in urbanized areas as a landscape component for barn swallows (hirundo rustica) nesting on concrete buildings.urbanization is one of the key factors in the population declines of many species. conversely, some species may favor urbanized areas. the barn swallow hirundo rustica is well known to breed in urban areas of japan, and uses both urban and farmland areas as habitat during the breeding season. specifically, this species often nests on concrete buildings and feeds in surrounding farmland. therefore, it was hypothesized that h. rustica is not strongly influenced by heavy urbanization and benefits f ...201525813627
expression of multiple sexual signals by fathers and sons in the east-mediterranean barn swallow: are advertising strategies heritable?the level of expression of sexually selected traits is generally determined by genes, environment and their interaction. in species that use multiple sexual signals which may be costly to produce, investing in the expression of one sexual signal may limit the expression of the other, favoring the evolution of a strategy for resource allocation among signals. as a result, even when the expression of sexual signals is condition dependent, the relative level of expression of each signal may be heri ...201525679206
transcontinental migratory connectivity predicts parasite prevalence in breeding populations of the european barn swallow.parasites exert a major impact on the eco-evolutionary dynamics of their hosts and the associated biotic environment. migration constitutes an effective means for long-distance invasions of vector-borne parasites and promotes their rapid spread. yet, ecological and spatial information on population-specific host-parasite connectivity is essentially lacking. here, we address this question in a system consisting of a transcontinental migrant species, the european barn swallow (hirundo rustica) whi ...201525611126
stress and success: individual differences in the glucocorticoid stress response predict behavior and reproductive success under high predation risk.a fundamental element of how vertebrates respond to stressors is by rapidly elevating circulating glucocorticoid hormones. individual variation in the magnitude of the glucocorticoid stress response has been linked with reproductive success and survival. but while the adaptive value of this response is believed to stem in part from changes in the expression of hormone-mediated behaviors, it is not clear how the behavior of stronger and weaker glucocorticoid responders differs during reproduction ...201425461975
an experimental analysis of the heritability of variation in glucocorticoid concentrations in a wild avian population.glucocorticoid hormones (cort) are predicted to promote adaptation to variable environments, yet little is known about the potential for cort secretion patterns to respond to selection in free-living populations. we assessed the heritable variation underlying differences in hormonal phenotypes using a cross-foster experimental design with nestling north american barn swallows (hirundo rustica erythrogaster). using a bivariate animal model, we partitioned variance in baseline and stress-induced c ...201425056627
modelling the progression of bird migration with conditional autoregressive models applied to ringing data.migration is a fundamental stage in the life history of several taxa, including birds, and is under strong selective pressure. at present, the only data that may allow for both an assessment of patterns of bird migration and for retrospective analyses of changes in migration timing are the databases of ring recoveries. we used ring recoveries of the barn swallow hirundo rustica collected from 1908-2008 in europe to model the calendar date at which a given proportion of birds is expected to have ...201425047331
nestling rearing is antioxidant demanding in female barn swallows (hirundo rustica).reproduction is a demanding activity, since organisms must produce and, in some cases, protect and provision their progeny. hence, a central tenet of life-history theory predicts that parents have to trade parental care against body maintenance. one physiological cost thought to be particularly important as a modulator of such trade-offs is oxidative stress. however, evidence in favour of the hypothesis of an oxidative cost of reproduction is contradictory. in this study, we manipulated the broo ...201424890700
large-scale patterns of genetic variation in a female-biased dispersing passerine: the importance of sex-based analyses.dispersal affects the distribution, dynamics and genetic structure of natural populations, and can be significantly different between sexes. however, literature records dealing with the dispersal of migratory birds are scarce, as migratory behaviour can notably complicate the study of dispersal. we used the barn swallow hirundo rustica as model taxon to investigate patterns of genetic variability in males and in females of a migratory species showing sex-biased dispersal. we collected blood samp ...201424886720
a trade-off between reproduction and feather growth in the barn swallow (hirundo rustica).physiological trade-offs mediated by limiting energy, resources or time constrain the simultaneous expression of major functions and can lead to the evolution of temporal separation between demanding activities. in birds, plumage renewal is a demanding activity, which accomplishes fundamental functions, such as allowing thermal insulation, aerodynamics and socio-sexual signaling. feather renewal is a very expensive and disabling process, and molt is often partitioned from breeding and migration. ...201424826890
life history, predation and flight initiation distance in a migratory bird.life-history trade-offs occur as a consequence of the compromise between maximization of different components such as the size and the number of clutches. flight initiation distance (fid) potentially constitutes a general proximate factor influencing such trade-offs reflecting the risks that individuals take. therefore, greater investment in reproduction occurs at a higher risk of death, resulting in selection for efficient flight morphology. i analysed long-term data on fid in a population of b ...201424797579
equal nonbreeding period survival in adults and juveniles of a long-distant migrant bird.in migrant birds, survival estimates for the different life-history stages between fledging and first breeding are scarce. first-year survival is shown to be strongly reduced compared with annual survival of adult birds. however, it remains unclear whether the main bottleneck in juvenile long-distant migrants occurs in the postfledging period within the breeding ranges or en route. quantifying survival rates during different life-history stages and during different periods of the migration cycle ...201424683458
first observation of african tigerfish hydrocynus vittatus predating on barn swallows hirundo rustica in flight.a population of african tigerfish hydrocynus vittatus from the schroda dam, actively prey on barn swallows hirundo rustica in flight. this behaviour was discovered during a radio telemetry study and documented using a motion picture video camera. these results show that an avivorous diet is a part of the feeding biology of h. vittatus, and may occur in other populations.201424354922
differential female access to males with large throat patches in the asian barn swallow hirundo rustica gutturalis.intersexual selection results from several processes, such as differential allocation and differential access, in addition to mating skews by mate choice. these processes can contribute to the evolution, maintenance, and geographic differentiation of male ornamentation, although the importance of these processes in male ornamentation remains poorly understood. the asian barn swallow hirundo rustica gutturalis is a socially monogamous songbird that exhibits biparental care and has red throat patc ...201324199856
multiple sexual signals and behavioral reproductive isolation in a diverging population.sexual trait divergence has been shown to play a role in the evolution of reproductive isolation. while variation in multiple sexual signals is common among closely related species, little is known about the role of these different axes of phenotype variation with respect to the evolution of behavioral reproductive isolation. here we study a unique population of barn swallows (hirundo rustica transitiva) that can be distinguished phenotypically from its neighboring populations only on the basis ...201324021403
signaling stress? an analysis of phaeomelanin-based plumage color and individual corticosterone levels at two temporal scales in north american barn swallows, hirundo rustica erythrogaster.sexually selected traits confer greater reproductive benefits to individuals with more elaborate forms of the signal. however, whether these signals convey reliable information about the physiology underlying trait development remains unknown in many species. the steroid hormone corticosterone (cort) mediates important physiological and behavioral processes during the vertebrate stress response, and cort secretion itself can be modulated by melanocortins. thus, sexually selected melanin-based pl ...201324013040
female plumage colour influences seasonal oxidative damage and testosterone profiles in a songbird.across diverse taxa, morphological traits mediate social interactions and mate selection. physiological constraints on signal elaboration have been widely documented, but the potential for trait display to influence physiological state remains poorly understood. we tested for the presence of causal links between ventral plumage colour-a trait known to covary with reproductive performance-and physiological measures in female north american barn swallows, hirundo rustica erythrogaster. naturally d ...201323966597
nestling telomere length does not predict longevity, but covaries with adult body size in wild barn swallows.telomere length and dynamics are increasingly scrutinized as ultimate determinants of performance, including age-dependent mortality and fecundity. few studies have investigated longevity in relation to telomere length (tl) in the wild and none has analysed longevity in relation to tl soon after hatching, despite the fact that telomere shortening may mostly occur early in life. we show that tl in nestling barn swallows (hirundo rustica) in the wild does not predict longevity. however, tl positiv ...201323883575
corticosterone secretion patterns prior to spring and autumn migration differ in free-living barn swallows (hirundo rustica l.).recent studies of long-distance migratory birds show that behavioural and physiological changes associated with predictable or unpredictable challenges during the annual cycle are distinctively regulated by hormones. corticosterone is the primary energy regulating hormone in birds. corticosterone levels are elevated during stresses but they are also modulated seasonally according to environmental conditions and life-history demands. we measured the baseline and stress-induced levels of corticost ...201323649753
timing of molt of barn swallows is delayed in a rare clock genotype.photoperiodic responses are major factors entraining circannual life-cycles, functioning to adaptively synchronize annual routines to seasonal fluctuations in ecological conditions. photoperiodism in physiology and behaviour is enforced by genes, including the vertebrate clock orthologues, which are associated, for example, with phenology of migration in fish and breeding in birds. however, the role of clock in photoperiodic plumage molt processes is unknown. we analyzed variation in molt schedu ...201323638351
viability is associated with melanin-based coloration in the barn swallow (hirundo rustica).pigmentation of body surface in animals can have multiple determinants and accomplish diverse functions. eumelanin and pheomelanin are the main animal pigments, being responsible of yellow, brownish-red and black hues, and have partly common biosynthetic pathways. many populations of vertebrates show individual variation in melanism, putatively with large heritable component. genes responsible for eu- or pheomelanogenesis have pleiotropic but contrasting effects on life-history traits, explainin ...201323573254
sexual dimorphism in melanin pigmentation, feather coloration and its heritability in the barn swallow (hirundo rustica).melanin is the main pigment in animal coloration and considerable variation in the concentrations of the two melanin forms (pheo- and eumlanin) in pigmented tissues exists among populations and individuals. melanin-based coloration is receiving increasing attention particularly in socio-sexual communication contexts because the melanocortin system has been hypothesized to provide a mechanistic basis for covariation between coloration and fitness traits. however, with few notable exceptions, litt ...201323469134
pheomelanin-based plumage coloration predicts survival rates in birds.higher vertebrates synthesize two forms of melanin: eumelanin and pheomelanin. while the adaptive functions of eumelanin are diverse, those of pheomelanin, which is phototoxic and whose production consumes a key intracellular antioxidant (glutathione), are not clear apart from being involved in color patterns that confer concealment. the factors that have favored the evolution of pheomelanin thus remain a mystery, causing this pigment even to have been considered an "accident of nature." a recen ...201323434778
population and colony-level determinants of tertiary sex ratio in the declining barn swallow.sex ratio of adults (tertiary sex ratio, tsr) is a major feature of animal populations with consequences for their behaviour, genetic structure and viability. spatial and temporal variation in tsr occurs within species but the mechanisms behind it are poorly understood. in this long-term study of a declining population of a socially monogamous, colonial, migratory bird, the barn swallow (hirundo rustica), we first analyzed population-level variation in tsr ( =  proportion of males) of yearlings ...201323418577
switching hemispheres: a new migration strategy for the disjunct argentinean breeding population of barn swallow (hirundo rustica).barn swallows (hirundo rustica) breed almost exclusively in the northern hemisphere. however, since the early 1980's, a small disjunct breeding population has become established in eastern argentina, presumably by birds previously derived from those breeding in north america. currently, it is unknown where these individuals go following breeding and how they have adjusted to a reversal in phenology. their austral wintering period corresponds to the breeding period of the northern ancestral popul ...201323383257
timing of arrival from spring migration is associated with flight performance in the migratory barn swallow.timing of arrival at the breeding grounds by migratory birds affects their mating success and access to superior resources, thus being a major factor associated with fitness. much empirical work has been devoted to investigate the condition dependence of arrival sequence of migrants and characteristics of individuals that influence arrival time from migration. surprisingly, there are no studies examining the relationship between flight performance of individual birds and their arrival time. i in ...201323293424
sex-related effects of reproduction on biomarkers of oxidative damage in free-living barn swallows (hirundo rustica).according to life-history theory, the allocation of limiting resources to one trait has negative consequences for other traits requiring the same resource, resulting in trade-offs among life-history traits, such as reproduction and survival. in vertebrates, oxidative stress is increasingly being considered among the physiological mechanisms forming the currency of life-history trade-offs. in this study of the barn swallow (hirundo rustica), we focus on the oxidative costs of reproduction, especi ...201223145037
geographical variation in reproductive ageing patterns and life-history strategy of a short-lived passerine bird.we investigated differences in ageing patterns in three measures of breeding performance in populations of barn swallows hirundo rustica l. from spain and denmark differing in breeding latitude and hence migration distance and duration of the breeding season. we found differences in ageing patterns between populations. generally, young (i.e. yearling) and old females (i.e. ≥ 5 years of age) laid their first eggs later and produced smaller clutches than middle-aged females (i.e. 2-4 years of age) ...201222994532
with a little help from my kin: barn swallow nestlings modulate solicitation of parental care according to nestmates' need.in altricial species, offspring competing for access to limiting parental resources (e.g. food) are selected to achieve an optimal balance between the costs of scrambling for food, the benefits of being fed and the indirect costs of subtracting food to relatives. as the marginal benefits of acquiring additional food decrease with decreasing levels of need, satiated offspring should be prone to favour access to food by their needy kin, thus enhancing their own indirect fitness, while concomitantl ...201222845831
longevity and lifetime reproductive success of barn swallow offspring are predicted by their hatching date and phenotypic quality.1. longevity is a major determinant of individual differences in darwinian fitness. several studies have analyzed the stochastic, time-dependent causes of variation in longevity, but little information exists from free-ranging animal populations on the effects that environmental conditions and phenotype early in ontogeny have on duration of life. 2. in this long-term (1993-2011) study of a migratory, colonial, passerine bird, the barn swallow (hirundo rustica), we analyzed longevity and, in a su ...201222531043
clock gene variation is associated with breeding phenology and maybe under directional selection in the migratory barn swallow.in diverse taxa, photoperiodic responses that cause seasonal physiological and behavioural shifts are controlled by genes, including the vertebrate clock orthologues, that encode for circadian oscillator mechanisms. while the genetic network behind circadian rhythms is well described, relatively few reports exist of the phenological consequences of and selection on clock genes in the wild. here, we investigated variation in breeding phenology in relation to clock genetic diversity in a long-dist ...201222506071
seasonal variation in the regulation of redox state and some biotransformation enzyme activities in the barn swallow (hirundo rustica l.).little is known of the normal seasonal variation in redox state and biotransformation activities in birds. in long-distance migratory birds, in particular, seasonal changes could be expected to occur because of the demands of migration and reproduction. in this study, we measured several redox parameters in the barn swallow (hirundo rustica l.) during the annual cycle. we captured the wintering barn swallows before spring migration in south africa, and we captured the barn swallows that arrived ...201222418707
low variation in the polymorphic clock gene poly-q region despite population genetic structure across barn swallow (hirundo rustica) populations.recent studies of several species have reported a latitudinal cline in the circadian clock gene, clock, which influences rhythms in both physiology and behavior. latitudinal variation in this gene may hence reflect local adaptation to seasonal variation. in some bird populations, there is also an among-individual association between clock poly-q genotype and clutch initiation date and incubation period. we examined clock poly-q allele variation in the barn swallow (hirundo rustica), a species wi ...201122216124
novel methods reveal shifts in migration phenology of barn swallows in south africa.many migratory bird species, including the barn swallow (hirundo rustica), have advanced their arrival date at northern hemisphere breeding grounds, showing a clear biotic response to recent climate change. earlier arrival helps maintain their synchrony with earlier springs, but little is known about the associated changes in phenology at their non-breeding grounds. here, we examine the phenology of barn swallows in south africa, where a large proportion of the northern european breeding populat ...201222072608
population genetics and morphological comparisons of migratory european (hirundo rustica rustica) and sedentary east-mediterranean (hirundo rustica transitiva) barn swallows.speciation processes are largely determined by the relative strength of divergent selection versus the magnitude of gene flow. the barn swallow (hirundo rustica) has a broad geographic distribution that encompasses substantial geographic variation in morphology and behavior. the european (h. r. rustica) and east-mediterranean (h. r. transitiva) subspecies are closely related, despite differing in morphological and life-history traits. to explore patterns of genetic differentiation and gene flow, ...201122071313
age before beauty? relationships between fertilization success and age-dependent ornaments in barn swallows.when males become more ornamented and reproduce more successfully as they grow older, phenotypic correlations between ornament exaggeration and reproductive success can be confounded with age effects in cross-sectional studies, and thus say relatively little about sexual selection on these traits. this is exemplified here in a correlative study of male fertilization success in a large colony of american barn swallows (hirundo rustica erythrogaster). previous studies of this species have indicate ...201121949464
testosterone, plumage colouration and extra-pair paternity in male north-american barn swallows.in most monogamous bird species, circulating testosterone concentration in males is elevated around the social female's fertile period. variation in elevated testosterone concentrations among males may have a considerable impact on fitness. for example, testosterone implants enhance behaviours important for social and extra-pair mate choice. however, little is known about the relationship between natural male testosterone concentration and sexual selection. to investigate this relationship we me ...201121853105
sex-related effects of an immune challenge on growth and begging behavior of barn swallow nestlings.parent-offspring conflicts lead the offspring to evolve reliable signals of individual quality, including parasite burden, which may allow parents to adaptively modulate investment in the progeny. sex-related variation in offspring reproductive value, however, may entail differential investment in sons and daughters. here, we experimentally manipulated offspring condition in the barn swallow (hirundo rustica) by subjecting nestlings to an immune challenge (injection with bacterial lipopolysaccha ...201121818393
quantitative genetics of migration syndromes: a study of two barn swallow populations.migration is a complex trait although little is known about genetic correlations between traits involved in such migration syndromes. to assess the migratory responses to climate change, we need information on genetic constraints on evolutionary potential of arrival dates in migratory birds. using two long-term data sets on barn swallows hirundo rustica (from spain and denmark), we show for the first time in wild populations that spring arrival dates are phenotypically and genetically correlated ...201121707815
antioxidant defenses predict long-term survival in a passerine bird.normal and pathological processes entail the production of oxidative substances that can damage biological molecules and harm physiological functions. organisms have evolved complex mechanisms of antioxidant defense, and any imbalance between oxidative challenge and antioxidant protection can depress fitness components and accelerate senescence. while the role of oxidative stress in pathogenesis and aging has been studied intensively in humans and model animal species under laboratory conditions ...201121573124
the effects of radiation on sperm swimming behavior depend on plasma oxidative status in the barn swallow (hirundo rustica).sperm are highly susceptible to reactive oxygen species (ros) that can damage sperm dna and structure, resulting in reduced fertilizing capacity. exposure to radioactive contamination can also impair sperm swimming behavior and fertilizing ability, both through a reduction of sperm dna integrity and via an increased generation of reactive oxygen species (ros). however, the relationship between individual oxidative status and sperm swimming behavior has never been investigated in any wild populat ...201121295152
determinants of age-dependent change in a secondary sexual character.many secondary sexual characters vary in a systematic way with the age of individuals, with young and old individuals displaying at lower levels than individuals of intermediate age. analyses quantifying the within-individual and among-individual components of phenotypic variation can help partition effects of phenotypic plasticity and selective mortality. we analysed phenotypic variation in the expression of a secondary sexual character, tail length, in male and female barn swallows hirundo rus ...201121175908
birth order, individual sex and sex of competitors determine the outcome of conflict among siblings over parental care.success in competition for limiting parental resources depends on the interplay between parental decisions over allocation of care and offspring traits. birth order, individual sex and sex of competing siblings are major candidates as determinants of success in sib-sib competition, but experimental studies focusing on the combined effect of these factors on parent-offspring communication and within-brood competitive dynamics are rare. here, we assessed individual food intake and body mass gain d ...201120943688
microorganisms associated with feathers of barn swallows in radioactively contaminated areas around chernobyl.the chernobyl catastrophe provides a rare opportunity to study the ecological and evolutionary consequences of low-level, environmental radiation on living organisms. despite some recent studies about negative effects of environmental radiation on macroorganisms, there is little knowledge about the effect of radioactive contamination on diversity and abundance of microorganisms. we examined abundance patterns of total cultivable bacteria and fungi and the abundance of feather-degrading bacterial ...201020640571
brain size, head size and behaviour of a passerine bird.a recent increase in comparative studies of the ecological and evolutionary consequences of brain size in birds and primates in particular have suggested that cognitive abilities constitute a central link. surprisingly, there are hardly any intraspecific studies investigating how individuals differing in brain size behave, how such individuals are distributed and how brain size is related to life history and fitness components. brain mass of the barn swallow hirundo rustica was strongly predicte ...201020487135
positive carotenoid balance correlates with greater reproductive performance in a wild bird.carotenoids can confer somatic and reproductive benefits, but most evidence is from captive animal experimentation or single time-point sampling. another perhaps more informative means by which to assess physiological contributions to animal performance is by tracking an individual's ability to increase or sustain carotenoids or other health-related molecules over time, as these are likely to be temporally variable.201020195540
body temperature and fever in a free-living bird.fever is an adaptive physiological response that animals use to fight infections by microorganisms. although used routinely by veterinary and medical doctors for assessment of health status, there are hardly any studies of fever in free-living animals. body temperature in a sample of more than 500 adult barn swallows hirundo rustica varied considerably, but was consistent among capture events. body temperature increased during the day, and reached a minimum in the middle of the breeding season. ...201020188208
phylogeny of the genus hirundo and the barn swallow subspecies complex.the cosmopolitan barn swallow complex (hirundo rustica and related hirundo species) provides a model system for studies of mate choice, sexual selection, and related topics in behavioral ecology, but the phylogenetic and phylogeographic relationships within this group are not yet completely resolved. we reconstructed the phylogeny of all 14 species of hirundo as well as all six barn swallow (h. rustica) subspecies using maximum likelihood and bayesian methods based on sequences of mitochondrial ...201020152914
survival benefits of post-fledging care: experimental approach to a critical part of avian reproductive strategies.1. caring for offspring beyond leaving the nest is an important but under-studied part of avian life histories. theory predicts that prolonged post-fledging parental care should yield fitness benefits such as increased fledgling survival. post-fledging care is also costly in terms of time and energy available for subsequent reproduction, moult or migration. so far, direct measurements of the fitness effects of the duration of post-fledging parental care are lacking. 2. in a partial cross-fosteri ...201020059611
body condition is associated with adrenocortical response in the barn swallow (hirundo rustica l.) during early stages of autumn migration.migration is an energy-demanding life-history period and also a significant population-limiting factor of long-distance migratory birds. it is important to understand how corticosterone, the main energy regulating hormone in birds, is associated with behavioural and physiological changes during migration. according to the migration modulation hypothesis (mmh), individual birds may express elevated levels of baseline corticosterone to facilitate fuelling, but down-regulate the adrenocortical resp ...201020052493
individual responses in spring arrival date to ecological conditions during winter and migration in a migratory bird.1. we studied lifetime arrival patterns in the barn swallow (hirundo rustica l.) in relation to variation in ecological conditions, as reflected by the normalized difference vegetation index (ndvi) in the sub-saharan winter quarters and at stopover sites in north africa. 2. migratory birds have recently advanced their arrival dates, but the relative role of microevolution and phenotypic plasticity as mechanisms of response to changing environmental conditions remains unknown. to distinguish betw ...200919531059
fine-tuned modulation of competitive behaviour according to kinship in barn swallow nestlings.kin selection theory predicts that, in species where progeny members compete for limiting parental care, individual offspring should be more prone to monopolize parental resources as their genetic relatedness to brood competitors decreases. mixed parentage among broodmates may arise as a consequence, for example, of extra-pair fertilization or brood parasitism events. in this experimental study of barn swallows (hirundo rustica), we reciprocally partially cross-fostered hatchlings between broods ...200919324749
divergent patterns of impact of environmental conditions on life history traits in two populations of a long-distance migratory bird.some areas have experienced recent dramatic warming due to climate change, while others have shown no change at all, or even recent cooling. we predicted that patterns of selection on life history would differ between southern and northern european populations of a long-distance migratory bird, the barn swallow hirundo rustica, because global patterns of weather as reflected by large-scale weather phenomena such as the north atlantic oscillation (nao) and the el niño-southern oscillation (enso) ...200919139919
a quantitative measure of migratory connectivity.the study of the extent of the connection between areas where populations of birds breed and areas where they winter has flourished in recent years mainly thanks to the development of new techniques, but also due to traditional ringing and recovery schemes, which allow tracking of individuals or populations linking wintering and breeding distributions. currently, studies on migratory connectivity focus on retention of breeding population spatial structure on the non-breeding grounds and vice ver ...200919108778
effect of current reproduction on apparent survival, breeding dispersal, and future reproduction in barn swallows assessed by multistate capture-recapture models.1. theoretical models predict a negative effect of current reproduction on breeding dispersal, survival and future reproduction, and many studies confirm these predictions. yet, results of most previous studies may be difficult to interpret because the fate of the affected individuals cannot always be observed. detection is almost always imperfect and some individuals emigrate from the study area, resulting in biased estimates of both survival and dispersal. 2. most studies bypass these problems ...200919040683
senescent sperm performance in old male birds.senescence is the deterioration of the phenotype with age caused by negative effects of mutations acting late in life or the physiological deterioration of vital processes. birds have traditionally been assumed to senescence slowly despite their high metabolic rates, high blood sugar levels and high body temperature. here we investigate the patterns of age-related performance of sperm of a long distance migrant, the barn swallow hirundo rustica, varying in age from 1 to 6 years, analysed by the ...200919032491
fitness consequences of pre- and post-fledging timing decisions in a double-brooded passerine.the fitness consequences of a delayed timing of breeding are expected to affect the temporal characteristics of the whole annual breeding system. one major problem in quantifying the fitness relevance of timing is that individual differences between pairs may cause the seasonal trend. differentials in juvenile survival due to pre-fledging timing decisions often only appear after fledging of the chicks. therefore, timing decisions in the post-fledging period, i.e., the duration of parental care, ...200818959311
dynamic feedback between phenotype and physiology in sexually selected traits.theory predicts that physiological costs of producing elaborate phenotypes assure the honesty of sexually selected traits. it is generally assumed that these physiological processes drive sexually selected displays. however, a recent study by safran and colleagues demonstrates that the manipulation of plumage ornaments in barn swallows alters the temporal course of circulating androgens, thus rejecting the scenario of a static, unidirectional relationship between physiology and sexual displays. ...200818951654
paternity and multiple signaling: effects of a secondary sexual character and song on paternity in the barn swallow.multiple signals may evolve because they provide independent information on the condition of a signaler. females should pay attention to male characters relative to their reliability as signals of male attractiveness or quality. since behavioral traits are flexible and, therefore, subject to strong environmental influences, females should weigh stable morphological signals higher in their choice of mates for genetic benefits than flexible behavioral traits, for example, by paying particular atte ...199818811354
sex-specific effects of albumen removal and nest environment manipulation on barn swallow nestlings.in avian species, maternal provisioning to the eggs is predicted to be more valuable for the offspring under adverse environmental conditions and intense sibling competition. however, studies manipulating both the amount of maternal pre-hatching resources and the harshness of post-hatching environment have seldom been performed to date. in this experimental study of barn swallow (hirundo rustica) nestlings, we tested the consequences of a reduction in the albumen content of the eggs for fitness- ...200818724741
the feather holes on the barn swallow hirundo rustica and other small passerines are probably caused by brueelia spp. lice.barn swallows hirundo rustica often have characteristic feather holes on wing and tail feathers. during the past 15 yr, several influential papers have been based on the assumption that these holes were chewed by the louse machaerilaemus malleus. we gathered feather-hole data from barn swallows and other passerines at 2 sites in hungary and correlated the presence of holes with louse infestations and, more specifically, with the occurrence of m. malleus versus other species of avian lice. the sh ...200818576840
sexual signal exaggeration affects physiological state in male barn swallows. 200818522812
microsatellite evolution: mutations, sequence variation, and homoplasy in the hypervariable avian microsatellite locus hru10.microsatellites are frequently used genetic markers in a wide range of applications, primarily due to their high length polymorphism levels that can easily be genotyped by fragment length analysis. however, the mode of microsatellite evolution is yet not fully understood, and the role of interrupting motifs for the stability of microsatellites remains to be explored in more detail. here we present a sequence analysis of mutation events and a description of the structure of repeated regions in th ...200818471288
male-biased brood sex ratio depresses average phenotypic quality of barn swallow nestlings under experimentally harsh conditions.sex allocation strategies are believed to evolve in response to variation in fitness costs and benefits arising from the production of either sex and can be influenced by the differential susceptibility of sons and daughters to environmental conditions. we tested the effects of manipulating brood size and the sex ratio of the nestmates and the effect of sex on the phenotypic quality of individual barn swallow (hirundo rustica) nestlings. brood enlargement, which results in harsh rearing conditio ...200818270745
the incidence of american swallow bugs (oeciacus vicarius) in barn swallow (hirundo rustica) colonies in northeast texas.the american swallow bug (oeciacus vicarius) is an important ectoparasite of cliff swallows (petrochelidon pyrrhonota) and is known to harbor several types of arbovirus. a recent study in northeast texas suggested that o. vicarius might occur in barn swallows (hirundo rustica) at rates much higher than previously thought. the purpose of this study was to determine the extent to which barn swallows in northeast texas are parasitized by o. vicarius and how well this parasite is adapting to this no ...200718260518
impaired swimming behaviour and morphology of sperm from barn swallows hirundo rustica in chernobyl.we investigated the motility and morphology of live sperm from barn swallows hirundo rustica breeding in radioactively contaminated areas around chernobyl and control areas in ukraine in order to test the hypothesis that swimming behaviour and morphology of sperm was impaired by radioactive contamination. we obtained sperm samples from 98% of sampled birds, thus avoiding sampling bias due to the fraction of males not producing sperm samples. analyses of within- and between-sample repeatability r ...200818218334
barn swallow chicks beg more loudly when broodmates are unrelated.parents of a variety of animal species distribute critical resources among their offspring according to the intensity of begging displays. kin selection theory predicts that offspring behave more selfishly in monopolizing parental care as relatedness with competitors declines. we cross-fostered two eggs between barn swallow (hirundo rustica) clutches and compared the loudness of begging between mixed and control broods under normal feeding conditions and after a period of food deprivation. beggi ...200818021204
glucocorticoid response to food availability in breeding barn swallows (hirundo rustica).parents feeding altricial nestlings have to trade-off the competing demands of self-maintenance and reproductive investment over their lifetime. corticosterone, a glucocorticoid hormone released by birds in response to stressors, might play a key role in regulating parental investment when conditions unexpectedly deteriorate. however, birds breeding in unpredictable environmental conditions have been shown not to increase circulating levels of corticosterone as a response to bad weather to avoid ...200817904557
induction of multiple criteria optimal classification rules for biological and medical data.to induce critical classification rules from observed data is a major task in biological and medical research. a classification rule is considered to be useful if it is optimal and simultaneously satisfies three criteria: is highly accurate, has a high rate of support, and is highly compact. however, current classification methods, such as rough set theory, neural networks, id3, etc., may only induce feasible rules instead of optimal rules. in addition, the rules found by current methods may onl ...200817869236
age-related change in breeding performance in early life is associated with an increase in competence in the migratory barn swallow hirundo rustica.1. we investigated age-related changes in two reproductive traits (laying date and annual fecundity) in barn swallows hirundo rustica l. using a mixed model approach to di-stinguish among between- and within-individual changes in breeding performance with age. 2. we tested predictions of age-related improvements of competence (i.e. constraint hypothesis) and age-related progressive disappearance of poor-quality breeders (i.e. selection hypothesis) to explain age-related increase in breeding perf ...200717714270
uninformative exaggeration of male sexual ornaments in barn swallows.models of sexual selection suggest that mate-choice preferences are favored because differences between males in their degree of ornamental exaggeration convey useful information about the direct or indirect benefits they have to offer [1-5]. such arguments assume that variation in male ornament size can be attributed to variation in the degree of sexually selected exaggeration. we provide the first test of this assumption by conducting tail-length experiments in male barn swallows. over the las ...200717412591
energy expenditure and wing beat frequency in relation to body mass in free flying barn swallows (hirundo rustica).many bird species steeply increase their body mass prior to migration. these fuel stores are necessary for long flights and to overcome ecological barriers. the elevated body mass is generally thought to cause higher flight costs. the relationship between mass and costs has been investigated mostly by interspecific comparison and by aerodynamic modelling. here, we directly measured the energy expenditure of barn swallows (hirundo rustica) flying unrestrained and repeatedly for several hours in a ...200717171355
predicting the consequences of carry-over effects for migratory populations.migratory animals present a unique challenge for predicting population size because they are influenced by events in multiple stages of the annual cycle that are separated by large geographic distances. here, we develop a model that incorporates non-fatal carry-over effects to predict changes in population size and show how this can be integrated with predictive models of habitat loss and deterioration. examples from barn swallows, greater snow geese and american redstarts show how carry-over ef ...200617148350
extrapair mating between relatives in the barn swallow: a role for kin selection?why do females of many species mate with more than one male? one of the main hypotheses suggests that female promiscuity is an insurance mechanism against the potential detrimental effects of inbreeding. accordingly, females should preferably mate with less related males in multiple or extrapair mating. here we analyse paternity, relatedness among mating partners, and relatedness between parents and offspring, in the socially monogamous north american barn swallow (hirundo rustica erythrogaster) ...200517148214
the design of complex sexual traits in male barn swallows: associations between signal attributes.variation in the expression of sexually selected traits among individuals is widely investigated on the premise that these traits evolved to signal male quality. significant repeatabilities of sexual signals and their associations with condition, mating success, survivorship and age may be the signatures of sexual selection. however, little is known about the relationship between these sexual attributes. here we studied 28 acoustic and visual traits in the barn swallow, hirundo rustica, that may ...200617040402
contaminant exposure of barn swallows nesting on bayou d'inde, calcasieu estuary, louisiana, usa.current and historical point source discharges, storm water runoff, and accidental spills have contaminated the water, sediment, and biota within the calcasieu estuary in southwestern louisiana. in 2003, barn swallow (hirundo rustica) eggs and nestlings were collected beneath two bridges that cross bayou d'inde, the most contaminated waterway within the calcasieu estuary. samples were also collected from a bridge over bayou teche, a reference site in south central louisiana. polychlorinated biph ...200616779575
an analysis of continent-wide patterns of sexual selection in a passerine bird.patterns of selection are widely believed to differ geographically, causing adaptation to local environmental conditions. however, few studies have investigated patterns of phenotypic selection across large spatial scales. we quantified the intensity of selection on morphology in a monogamous passerine bird, the barn swallow hirundo rustica, using 6495 adults from 22 populations distributed across europe and north africa. according to the classical darwin-fisher mechanism of sexual selection in ...200616739465
differential effects of egg albumen content on barn swallow nestlings in relation to hatch order.in diverse animal taxa, egg mass variation mediates maternal effects with long-term consequences for offspring ontogeny and fitness. patterns of egg mass variation with laying order differ considerably among birds, but no study has experimentally investigated the function of variation in albumen or yolk egg content in the wild. in barn swallows (hirundo rustica), absolute and relative albumen mass increased with egg laying order. experimental albumen removal delayed hatching, had larger negative ...200616674593
yolk androgens in the barn swallow (hirundo rustica): a test of some adaptive hypotheses.maternal effects such as androgen in avian eggs can mediate evolutionary responses to selection, allowing manipulation of offspring phenotype and promoting trans-generational adaptive effects. we tested the predictions of two adaptive hypotheses that have been proposed to explain female variation in yolk androgen allocation in birds, using the barn swallow hirundo rustica as a model. we found no support for the first hypothesis proposing that yolk androgen varies as a function of breeding densit ...200616405584
reproduction and migration in relation to senescence in the barn swallow hirundo rustica: a study of avian 'centenarians'.a. p. moller, f. de lope and n. saino: reproduction and migration in relation to senescence in the barn swallow hirundo rustica: a study of avian 'centenarians'. senescence reflects the decrease in age-dependent residual reproductive value, and a previous study of a cohort of migratory barn swallows (hirundo rustica) that had reached advanced ages for this species (at least five years old) provided evidence consistent with senescence such as reduced reproductive performance and increased abundan ...200523598664
dynamic paternity allocation as a function of male plumage color in barn swallows.paternity in male animals can be influenced by their phenotypic signals of quality. accordingly, the behavior underlying patterns of paternity should be flexible as signals of quality change. to evaluate the dynamics of paternity allocation, we analyzed paternity before and after manipulating plumage coloration, a known signal of quality, in male barn swallows hirundo rustica. we found that, in successive breeding bouts, only males whose plumage color was experimentally enhanced received greater ...200516195460
behavioural and energetic responses to body state in male and female barn swallows (hirundo rustica).females and males often have different roles when attending young. the factors responsible for shifts in the balance of effort when both sexes provision their young are not clear. this study asked if sex-specific behaviour and provisioning rules in barn swallows (hirundo rustica) were dependent on individual body-state or affected by the state of their provisioning partner. to assess this male and female barn swallows underwent overnight warming manipulations whilst provisioning 10-14 day old ne ...200515846052
rapid evolutionary change in a secondary sexual character linked to climatic change.the ability of organisms to respond evolutionarily to rapid climatic change is poorly known. secondary sexual characters show the potential for rapid evolutionary change, as evidenced by strong divergence among species and high evolvability. here we show that the length of the outermost tail feathers of males of the socially monogamous barn swallow hirundo rustica, feathers that provide a mating advantage to males, has increased by more than 1 standard deviation during the period from 1984 to 20 ...200515715854
heterogeneity in stable isotope profiles predicts coexistence of populations of barn swallows hirundo rustica differing in morphology and reproductive performance.population studies assume that individuals belonging to a study population are homogeneous for natal and breeding origin, although this assumption is rarely tested. we tested for heterogeneity in stable-isotope profiles (delta15n, delta13c, deltad) of feathers grown in the african winter quarters from a danish breeding population of adult barn swallows, hirundo rustica. deuterium isotope values did not provide useful information on population segregation of wintering swallows in africa. however, ...200415306333
adaptive site selection rules and variation in group size of barn swallows: individual decisions predict population patterns.variation in group size is ubiquitous among socially breeding organisms. an alternative to the traditional examination of average reproductive success in groups of different sizes is to examine individual decision making by determining the cues used for site selection. once factors used for decision making are known, one can determine whether group-level patterns, such as group size variation, are emergent properties of individual-level decision rules. the advantage of this alternative approach ...200415278838
daily energy expenditure of male barn swallows correlates with tail-streamer length: handicap-mediated foraging strategies.daily energy expenditure (dee) of male barn swallows (hirundo rustica), measured using the doubly labelled water technique, correlated with streamer length. contrary to predictions derived from previous findings, neither a positive linear nor a u-shaped relationship was found between dee and streamer length. instead, an n-shaped curve showed that the highest dee corresponded to an intermediate streamer length of 119 mm. a model incorporating estimates of resting metabolism and flight energy expe ...200415252971
geographic variation in the g matrices of wild populations of the barn swallow.in this paper, we present an analysis of genetic variation in three wild populations of the barn swallow, hirundo rustica. we estimated the p, e, and g matrices for six linear morphological measurements and tested for variation among populations using the flury hierarchical method and the jackknife followed by manova method. because of nonpositive-definite matrices, we had to employ 'bending' to analyse the g and e matrices with the flury method. both statistical methods agree in finding that th ...200415218508
ecological conditions during winter affect sexual selection and breeding in a migratory bird.populations of migratory birds have undergone marked declines, although the causes and mechanisms remain unknown. because environmental effects on population dynamics are mediated by the effects of ecological factors on individuals, understanding changes in individual phenotypes in response to ecological conditions is key to understanding population trends. we show that breeding individuals of a declining population of trans-saharan migratory barn swallows, hirundo rustica, were affected by envi ...200415209100
individual variation in microsatellite mutation rate in barn swallows.the hypermutable nature of some microsatellite loci implies realistic possibilities for the large-scale detection of germline mutations by pedigree analysis. we have developed a model system for mutation analysis by the characterisation of patterns of mutation at three hypervariable microsatellites (two tetranucleotide and one pentanucleotide repeat loci) in barn swallows, all three markers having mutation rates at the percentage level. here, we study how the mutation rate varies between individ ...200414698418
humoral immune response in relation to senescence, sex and sexual ornamentation in the barn swallow (hirundo rustica).performance of animals may decline with age. the effects of senescence, however, may differ between the sexes because of differences in physiology and behaviour. acquired immunity provides hosts with efficient mechanisms of anti-parasite defence, but the effect of senescence on immunocompetence has never been studied in natural populations. in the barn swallow (hirundo rustica), primary antibody response to an antigen during one breeding season declined with age in females, while secondary respo ...200314640404
an illustration of variable precision rough set theory: the gender classification of the european barn swallow (hirundo rustica).this paper introduces a new technique in the investigation of object classification and illustrates the potential use of this technique for the analysis of a range of biological data, using avian morphometric data as an example. the nascent variable precision rough sets (vprs) model is introduced and compared with the decision tree method id3 (through a 'leave n out' approach), using the same dataset of morphometric measures of european barn swallows (hirundo rustica) and assessing the accuracy ...200312909253
ectoparasites and reproductive trade-offs in the barn swallow (hirundo rustica).parents are predicted to trade offspring number and quality against the costs of reproduction. in altricial birds, parasites can mediate these costs because intensity of parasitism may increase with parental effort. in addition, parasites may mediate a trade-off between offspring number and quality because nestlings in large broods may have reduced anti-parasite immune defence. in this study, we experimentally analysed the effect of brood size on infestation by an ectoparasitic mite in nests of ...200228547300
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