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Anders Pape Moller - One of the best experts on this subject based on the ideXlab platform.

  • A new species of parasitic mites of the genus Syringophiloidus Kethley 1970 (Acari: Syringophilidae) from the barn swallow Hirundo Rustica Linnaeus, 1758.
    Parasite, 2020
    Co-Authors: Maciej Skoracki, Anders Pape Moller, Piotr Tryjanowski
    Abstract:

    Une nouvelle espece d'acarien parasite Syringophiloidus hirundinis (Acari : Syringophilidae) est decrite au niveau du plumage de l'hirondelle Hirundo Rustica Cette nouvelle espece est observee avec une prevalence de 17,1 % au niveau des plumes des deux pointes de la queue (N = 208 hirondelles adultes) pendant la saison de reproduction de l'oiseau L'intensite de l'infestation est de 9,7 acariens adultes par plumes de queue. Le sex ratio est biaise en faveur des femelles car 7,5 % seulement des oiseaux etaient des mâles (20/3).

  • viability and expression of sexual ornaments in the barn swallow Hirundo Rustica a meta analysis
    Journal of Evolutionary Biology, 2017
    Co-Authors: Andrea Romano, Nicola Saino, Anders Pape Moller
    Abstract:

    : Sexual selection results in the evolution of exaggerated secondary sexual characters that can entail a viability cost. However, in species where sexual ornaments honestly reflect individual quality, the viability cost of secondary sexual characters may be overwhelmed by variation in individual quality, leading to expect that individuals with the largest secondary sexual characters show higher, rather than lower viability. Here, we used meta-analyses to test whether such expected positive relationship between sexual ornamentation and viability exists in the barn swallow Hirundo Rustica, which is one of the most studied model species of sexual selection under field conditions. We found a mean positive effect size of viability in relation to the expression of secondary sexual characters of 0.181 (CI: 0.084-0.278), indicating that in this species the more ornamented individuals are more viable, and therefore of high quality. Analyses of moderator variables showed similar effects in males and females, the H. r. Rustica subspecies rather than others and tail length rather than other secondary sexual characters. Future research emphasis on other subspecies than the European one and secondary sexual characters than tail length may help identify the sources of heterogeneity in effect sizes.

  • Viability and expression of sexual ornaments in the barn swallow Hirundo Rustica: a meta‐analysis
    Journal of Evolutionary Biology, 2017
    Co-Authors: Andrea Romano, Nicola Saino, Anders Pape Moller
    Abstract:

    Sexual selection results in the evolution of exaggerated secondary sexual characters that can entail a viability cost. However, in species where sexual ornaments honestly reflect individual quality, the viability cost of secondary sexual characters may be overwhelmed by variation in individual quality, leading to expect that individuals with the largest secondary sexual characters show higher, rather than lower viability. Here, we used meta‐analyses to test whether such expected positive relationship between sexual ornamentation and viability exists in the barn swallow Hirundo Rustica, which is one of the most studied model species of sexual selection under field conditions. We found a mean positive effect size of viability in relation to the expression of secondary sexual characters of 0.181 (CI: 0.084–0.278), indicating that in this species the more ornamented individuals are more viable, and therefore of high quality. Analyses of moderator variables showed similar effects in males and females, the H. r. Rustica subspecies rather than others and tail length rather than other secondary sexual characters. Future research emphasis on other subspecies than the European one and secondary sexual characters than tail length may help identify the sources of heterogeneity in effect sizes.

  • intensity of melanin based color and risk of predation in the barn swallow Hirundo Rustica
    Acta Ornithologica, 2014
    Co-Authors: Ismael Galvan, Jan Tottrup Nielsen, Anders Pape Moller
    Abstract:

    Abstract. Predators are supposed to exert strong selection pressures on their prey, especially when phenotypic traits such as secondary sexual characters promote mating success at the expense of costs in terms of natural selection. Signaling theory predicts that individuals of superior phenotypic quality will enjoy an advantage in term of mating success, but also in term of natural selection, if such individuals are in prime condition both before and after development of exaggerated secondary sexual characters. We tested this prediction in the Barn Swallow Hirundo Rustica being preyed upon by the Eurasian Sparrowhawk Accipiter nisus, using extensive samples of feathers from prey and non-prey. We measured tail length and coloration of outermost tail feathers in the black area of the proximal and distal part of tail feathers, but also the white spot of the tail feathers. Prey had significantly less dark distal, but not proximal parts of their tails, while there was no difference in coloration of the white s...

  • a multi isotope δ13c δ15n δ2h approach to connecting european breeding and african wintering populations of barn swallow Hirundo Rustica
    Animal Migration, 2012
    Co-Authors: Keith A Hobson, Anders Pape Moller, Steven L Van Wilgenburg
    Abstract:

    In the last few decades, there has been renewed interest in establishing connections between breeding and wintering populations of long-distance migratory birds [1,2]. Much of this interest is based on the clear recognition that factors occurring at one period of the annual cycle can influence events occurring at another [3-7]. Such seasonal interactions can reveal ultimate fitness consequences of the choice of wintering and stopover locations made by birds that travel to breed. For example, birds occupying favorable wintering habitats are more likely to achieve a suitable migratory body condition and arrive first on the A multi-isotope (δ13C, δ15N, δ2H) approach to connecting European breeding and African wintering populations of barn swallow (Hirundo Rustica)

Nicola Saino - One of the best experts on this subject based on the ideXlab platform.

  • smrt long read sequencing and direct label and stain optical maps allow the generation of a high quality genome assembly for the european barn swallow Hirundo Rustica Rustica
    bioRxiv, 2018
    Co-Authors: Giulio Formenti, Luca Canova, Andrea Bonisolialquati, Matteo Chiara, Lucy Poveda, Keesjan Francoijs, Luca Enrico Angelo Gianfranceschi, David S Horner, Nicola Saino
    Abstract:

    Background: The barn swallow (Hirundo Rustica) is a migratory bird that has been the focus of a large number of ecological, behavioural and genetic studies. To facilitate further population genetics and genomic studies, here we present a reference genome assembly for the European subspecies (Hirundo Rustica Rustica). Findings: As part of the Genome10K (G10K) effort on generating high quality vertebrate genomes, we have assembled a highly contiguous genome assembly using Single Molecule Real-Time (SMRT) DNA sequencing and several Bionano optical map technologies. We compared and integrated optical maps derived both from the Nick, Label, Repair and Stain and from the Direct Label and Stain technologies. As proposed by Bionano, the direct labelling system more than doubled the scaffold N50 with respect to the nickase system. The dual enzyme hybrid scaffold led to a further marginal increase in scaffold N50 and an overall increase of confidence in scaffolds. After removal of haplotigs, the final assembly is approximately 1.21 Gbp in size, with a scaffold N50 value of over 25.95 Mbp. Conclusions: This high-quality genome assembly represents a valuable resource for further studies of population genetics of the barn swallow and for studies concerning the evolution of avian genomes. It also represents one of the very first genomes assembled combining SMRT long-read sequencing with the new Bionano Direct Label and Stain technology for scaffolding, highlighting the potential of this methodology to contribute to substantial increases in the contiguity of genome assemblies.

  • viability and expression of sexual ornaments in the barn swallow Hirundo Rustica a meta analysis
    Journal of Evolutionary Biology, 2017
    Co-Authors: Andrea Romano, Nicola Saino, Anders Pape Moller
    Abstract:

    : Sexual selection results in the evolution of exaggerated secondary sexual characters that can entail a viability cost. However, in species where sexual ornaments honestly reflect individual quality, the viability cost of secondary sexual characters may be overwhelmed by variation in individual quality, leading to expect that individuals with the largest secondary sexual characters show higher, rather than lower viability. Here, we used meta-analyses to test whether such expected positive relationship between sexual ornamentation and viability exists in the barn swallow Hirundo Rustica, which is one of the most studied model species of sexual selection under field conditions. We found a mean positive effect size of viability in relation to the expression of secondary sexual characters of 0.181 (CI: 0.084-0.278), indicating that in this species the more ornamented individuals are more viable, and therefore of high quality. Analyses of moderator variables showed similar effects in males and females, the H. r. Rustica subspecies rather than others and tail length rather than other secondary sexual characters. Future research emphasis on other subspecies than the European one and secondary sexual characters than tail length may help identify the sources of heterogeneity in effect sizes.

  • Viability and expression of sexual ornaments in the barn swallow Hirundo Rustica: a meta‐analysis
    Journal of Evolutionary Biology, 2017
    Co-Authors: Andrea Romano, Nicola Saino, Anders Pape Moller
    Abstract:

    Sexual selection results in the evolution of exaggerated secondary sexual characters that can entail a viability cost. However, in species where sexual ornaments honestly reflect individual quality, the viability cost of secondary sexual characters may be overwhelmed by variation in individual quality, leading to expect that individuals with the largest secondary sexual characters show higher, rather than lower viability. Here, we used meta‐analyses to test whether such expected positive relationship between sexual ornamentation and viability exists in the barn swallow Hirundo Rustica, which is one of the most studied model species of sexual selection under field conditions. We found a mean positive effect size of viability in relation to the expression of secondary sexual characters of 0.181 (CI: 0.084–0.278), indicating that in this species the more ornamented individuals are more viable, and therefore of high quality. Analyses of moderator variables showed similar effects in males and females, the H. r. Rustica subspecies rather than others and tail length rather than other secondary sexual characters. Future research emphasis on other subspecies than the European one and secondary sexual characters than tail length may help identify the sources of heterogeneity in effect sizes.

  • No short-term effects of geolocators on flight performance of an aerial insectivorous bird, the Barn Swallow (Hirundo Rustica)
    Journal of Ornithology, 2016
    Co-Authors: Piotr Matyjasiak, Diego Rubolini, Maria Romano, Nicola Saino
    Abstract:

    Miniaturized light-level geolocators are becoming increasingly popular devices for the study of avian migration. However, the effects of these devices on birds’ flight behaviour, and hence fitness components, are poorly known. We investigated the effect of miniaturized geolocators on flight performance of the Barn Swallow ( Hirundo Rustica ), which may be especially susceptible to geolocator deployment as it is a small (~20 g), aerially insectivorous, long-distance migratory species. We tested whether miniaturized geolocators (~3.5 % of body mass) affected short-term flight performance traits of breeding males by comparing flight manoeuvrability, velocity and acceleration of geolocator-equipped versus control (handled only) birds in flight tunnels. We used a robust experimental design wherein the within-individual change in flight performance was compared between geolocator-equipped birds (after allowing for a period of acclimation) and control birds (that were also tested twice). We found no statistically significant evidence that short-term flight performance traits were affected by geolocator deployment. Here we discuss the implications of our findings for the deployment of geolocators in studies of migratory behaviour of small birds. Geolokatoren haben keine kurzfristigen Auswirkungen auf die Flugleistung der in der Luft nach Insekten jagenden Rauchschwalbe Hirundo Rustica Miniaturisierte Helldunkelgeolokatoren werden zunehmend für Untersuchungen des Vogelzugs eingesetzt. Die Auswirkungen dieser Geräte auf das Flugverhalten und somit auf gewisse Fitnesskomponenten der Vögel sind jedoch nur schlecht verstanden. Wir haben den Einfluss von miniaturisierten Geolokatoren auf die Flugleistung der Rauchschwalbe ( Hirundo Rustica ) untersucht, die als kleiner (20 g), in der Luft nach Insekten jagender Langstreckenzieher besonders empfindlich auf den Einsatz von Geolokatoren reagieren könnte. Wir haben getestet, ob miniaturisierte Geolokatoren (3.5 % der Körpermasse) die Flugleistung brütender Männchen kurzfristig beeinflussen. Hierfür haben wir in Windtunneln die Manövrierfähigkeit, Geschwindigkeit und Beschleunigung von mit Geolokatoren ausgestatteten Vögeln und Kontrollvögeln, die lediglich gehandhabt wurden, verglichen. Wir haben ein robustes experimentelles Design verwendet, bei dem die individuelle Änderung der Flugleistung von mit Geolokatoren ausgestatteten Vögeln (d.h. vor Anbringung des Geräts und nachdem sich das Tier an das Gerät gewöhnt hatte) und Kontrollvögeln (die ebenfalls zweimal getestet wurden) verglichen wurde. Wir fanden keine statistisch signifikanten Hinweise darauf, dass die Flugleistung kurzfristig durch den Geolokatoreneinsatz beeinträchtigt wurde. Wir diskutieren die Folgen unserer Befunde für den Geolokatoreneinsatz in Studien des Zugverhaltens von Kleinvögeln.

  • nestling rearing is antioxidant demanding in female barn swallows Hirundo Rustica
    Naturwissenschaften, 2014
    Co-Authors: Diego Rubolini, Maria Romano, Roberto Ambrosini, Manuela Caprioli, David Costantini, Andrea Bonisolialquati, Nicola Saino
    Abstract:

    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 brood size of wild barn swallows Hirundo Rustica soon after hatching of their nestlings to test whether an increase in nestling rearing effort translates into an increased oxidative damage and a decreased antioxidant protection at the end of the nestling rearing period. We found that, while plasma oxidative damage was unaffected by brood size enlargement, females rearing enlarged broods showed a decrease in plasma non-enzymatic antioxidants during the nestling rearing period. This was not the case among females rearing reduced broods and among males assigned to either treatment. Moreover, individuals with higher plasma oxidative damage soon after the brood size manipulation had lower plasma non-enzymatic antioxidants at the end of the nestling rearing period, suggesting that non-enzymatic antioxidants were depleted to buffer the negative effects of high oxidative damage. Our findings point to antioxidant depletion as a potential mechanism mediating the cost of reproduction among female birds.

Florentino De Lope - One of the best experts on this subject based on the ideXlab platform.

  • variation in sperm morphometry and sperm competition among barn swallow Hirundo Rustica populations
    Behavioral Ecology and Sociobiology, 2013
    Co-Authors: Terje Laskemoen, Oddmund Kleven, Florentino De Lope, Andrea Bonisolialquati, Jaroslav Cepák, Tomáš Albrecht, Lars Erik Johannessen, Ignacio G Hermosell, Alfonso Marzal
    Abstract:

    Spermatozoa vary greatly in size and shape among species across the animal kingdom. Postcopulatory sexual selection is thought to be the major evolutionary force driving this diversity. In contrast, less is known about how sperm size varies among populations of the same species. Here, we investigate geographic variation in sperm size in barn swallows Hirundo Rustica, a socially monogamous passerine with a wide Holarctic breeding distribution. We included samples from seven populations and three subspecies: five populations of ssp. Rustica in Europe (Czech, Italy, Norway, Spain, and Ukraine), one population of ssp. transitiva in Israel, and one population of ssp. erythrogaster in Canada. All sperm traits (head length, midpiece length, tail length, and total length) varied significantly among populations. The variation among the European Rustica populations was much lower than the differences among subspecies, indicating that sperm traits reflect phylogenetic distance. We also performed a test of the relationship between the coefficient of between-male variation in total sperm length and extrapair paternity levels across different populations within a species. Recent studies have found a strong negative relationship between sperm size variation and extrapair paternity among species. Here, we show a similar negative relationship among six barn swallow populations, which suggests that the variance in male sperm length in a population is shaped by the strength of stabilizing postcopulatory sexual selection.

  • geographic patterns of natal dispersal in barn swallows Hirundo Rustica from denmark and spain
    Behavioral Ecology and Sociobiology, 2009
    Co-Authors: Javier Balbontin, Anders Pape Moller, Alfonso Marzal, Ignacio G Hermosell, Maribel Reviriego, Florentino De Lope
    Abstract:

    Dispersal is an important factor that determines the degree of gene flow and, hence, the degree of differentiation among populations. Using two long-term datasets on natal philopatry and short-distance dispersal in barn swallows Hirundo Rustica from Denmark and Spain, we evaluated the fitness costs and benefits and test a number of predictions about the functional significance of dispersal. The proportion of philopatric individuals was more than six times larger in Spain than in Denmark, with a higher rate of philopatry in males than in females. Dispersal propensity decreased in both populations during the course of the study. Males from the more philopatric Spanish population lived longer when philopatric rather than dispersing while that was not the case for either sex of the less philopatric Danish population. There were large differences in dispersal propensity among cohorts and breeding sites, suggesting that sites differed in their suitability as sites for immigrants. We found no evidence consistent with the mate competition hypothesis suggesting that males in better condition or with larger condition-dependent secondary sexual characters were more likely to be philopatric. These findings suggest that there is a high degree of intraspecific variation in dispersal propensity between populations, probably relating to local differences in costs and benefits of philopatry and dispersal.

  • digit ratios secondary sexual characters and condition in barn swallows Hirundo Rustica
    Behavioral Ecology, 2008
    Co-Authors: Amelie Dreiss, Florentino De Lope, C Navarro, Anders Pape Moller
    Abstract:

    The second and fourth digit length ratio (2D:4D) is sexually dimorphic in many vertebrates. This ratio has been suggested to provide an estimate of steroid levels encountered during prenatal development, which may have organizational consequences for physiology and behavior of adults. However, recent studies showed that the relation between digit ratio and steroids seems inconsistent and may vary among species and populations. We tested the hypothesis that digit ratios would be correlated with the expression of secondary sexual characters, using the barn swallow (Hirundo Rustica) as a model system. This was done by testing whether variation in 2D:4D ratio was correlated with tail length and features of song, which are important secondary sexual characters positively correlated with circulating steroid concentration in adult birds. Furthermore, we examined the prediction that male and female digit ratios would correlate with body mass in an antagonistic way. There was no significant sexual dimorphism in digit ratio, which may be due to low levels of sexual selection in this population. Adult right 2D:4D ratio was negatively linked to tail length but not to male song output. Moreover, right 2D:4D ratio was negatively correlated with body mass in male and positively in females. These results are consistent with high digit ratios reflecting low levels of testosterone in this bird species. Copyright 2008, Oxford University Press.

  • haematocrit is weakly related to condition in nestling barn swallows Hirundo Rustica
    Ibis, 2006
    Co-Authors: José Javier Cuervo, Anders Pape Moller, Florentino De Lope
    Abstract:

    Currently, there is no agreement about the suitability of haematocrit (the proportion of blood volume occupied by packed red blood cells) as a predictor of condition in birds. In order to clarify this point, genetic and environmental components of phenotypic variation for a number of traits were estimated in nestling Barn Swallows Hirundo Rustica by means of a partial cross-fostering experiment. The studied traits were haematocrit, two morphological traits used as estimates of condition in birds (body mass and body mass relative to body size) and a morphological trait that presumably is not associated with condition (tarsus length). First, we found that body mass relative to body size was related to haematocrit, supporting the suggestion that haematocrit reflects condition in this species. Secondly, we found that the coefficient of residual (i.e. environmental) variation of haematocrit was larger than that of tarsus length, but smaller than those of body mass or body mass relative to body size. Under the hypothesis that traits closely related to condition (and, ultimately, to fitness) are characterized by large residual variance, these results also suggest that haematocrit is related to condition, but that this relationship must be weak. Therefore, the use of haematocrit as an estimate of condition is not recommended. Finally, heritabilities of the studied traits were calculated, differing significantly from zero only for tarsus length, the trait with the smallest residual variation. However, a consistent pattern in the relationship between heritability and genetic variation was not found.

  • structural coloration and sexual selection in the barn swallow Hirundo Rustica
    Behavioral Ecology, 2002
    Co-Authors: Claire Perrier, Anders Pape Moller, Florentino De Lope, Paola Ninni
    Abstract:

    Structural coloration has been hypothesized to play a role in sexual selection, and we tested whether this was the case in a field study of the barn swallow Hirundo Rustica. The dorsal iridescent plumage of barn swallows has a strong reflectance in the ultraviolet (UV) region, with adult males on average reflecting 8-9% more than adult females, as revealed by a 2-year study in southwestern Spain. The correlation between structural coloration (described by the reflectance in the UV part of the spectrum, UV chroma and blue chroma) and three other secondary sexual characters significantly associated with male mating success (tail length, tail asymmetry, and red facial coloration) was weak and generally nonsignificant. Nor was there a significant relationship between color parameters and body condition. We tested for an association between structural coloration of the dorsal plumage and sexual selection in a number of independent tests. Arrival date of males was not significantly related to color; there was no significant relationship between coloration and probability of survival or age; mated males did not have stronger reflectance than unmated males; and the duration of the premating period was not significantly related to color. Reproductive success was not significantly correlated with plumage coloration in males, nor was the feeding rate of offspring by brightly colored males higher than that of males with less bright plumage. Given that sample sizes were large, and the power of statistical tests high, we conclude that current sexual selection on the coloration of the dorsal plumage in the barn swallow is, at best, weak. Copyright 2002.

Rebecca J Safran - One of the best experts on this subject based on the ideXlab platform.

  • predictors and consequences of nest switching behavior in barn swallows Hirundo Rustica erythrogaster
    The Auk, 2018
    Co-Authors: Kyle Donahue, Amanda K Hund, Iris I Levin, Rebecca J Safran
    Abstract:

    ABSTRACT Nest-switching is an important breeding strategy for multiple-brooded bird species. When deciding whether or not to switch nests for subsequent breeding attempts, pairs must weigh the costs and benefits of various factors related to the number of fledglings of the first breeding attempt, the likelihood of nest predation, and qualities of the nest environment, such as nest ectoparasites and the age of the nest. In this study, we analyzed the predictors and consequences of nest-switching behavior at 6 breeding sites of North American Barn Swallows (Hirundo Rustica erythrogaster), where 60% of pairs that raised 2 broods within a season switched nests for a second breeding attempt. Pairs often reused existing (old) nests constructed during previous years, and pairs that settled in old nests for their first breeding attempt were the most likely to switch nests for a second breeding attempt. Contrary to previous studies, nest predation and nest ectoparasitism had no influence on whether or not pairs sw...

  • population genetics and morphological comparisons of migratory european Hirundo Rustica Rustica and sedentary east mediterranean Hirundo Rustica transitiva barn swallows
    Journal of Heredity, 2012
    Co-Authors: Rebecca J Safran, Yoni Vortman, Arnon Lotem, Andrew Mcgowan, Matthew R Evans, Irby J Lovette
    Abstract:

    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, we compared morphological and genetic variation among the nonmigratory breeding population of H. r. transitiva from Israel and the migratory population of H. r. Rustica that passes through Israel and compared it with the genetic differentiation between H. r. transitiva from Israel and a breeding population of H. r. Rustica from the United Kingdom that uses a different migratory flyway. Mitochondrial haplotype network analysis suggests that the European and East-Mediterranean populations are intermixed, although there was low but significant genetic differentiation between the subspecies based on both mitochondrial (FST 5 0.025‐0.033) and microsatellite (FST 5 0.009‐0.014) loci. Coalescent-based analyses suggest recent divergence and substantial gene flow between these populations despite their differences in morphological and behavioral traits. The results suggest that these subspecies are undergoing a differentiation process in the face of gene flow, with selection possibly operating on sexually selected traits.

  • nest site selection in the barn swallow Hirundo Rustica what predicts seasonal reproductive success
    Canadian Journal of Zoology, 2006
    Co-Authors: Rebecca J Safran
    Abstract:

    Despite hundreds of studies, we know very little about the causes and fitness-related consequences of nest-site selection. For example, it is not typically known whether the rarely reported fitness consequences of site selection are the result of nest, individual, or nest-site variables or combinations of these factors. Reuse of previously constructed nest sites is a prevalent behavior in many animals and offers the opportunity to experimentally tease apart whether seasonal reproductive success is a function of nest, individual, or nest-site characteristics. I used observational and experimental data to test three hypotheses related to these factors in association with barn swallow (Hirundo Rustica L., 1758) nest reuse. While both nest and individual characteristics explain variation in seasonal reproductive success, nest location per se is not an important factor defining the outcome of nest-site selection. Whereas traits related to habitat and individual characteristics are likely confounded in correlat...

Paola Ninni - One of the best experts on this subject based on the ideXlab platform.

  • yolk androgens in the barn swallow Hirundo Rustica a test of some adaptive hypotheses
    Journal of Evolutionary Biology, 2006
    Co-Authors: Paola Ninni, F De Lope, Andre Lacroix, Claire Tirard, Alfonso Marzal, Pape A Moller
    Abstract:

    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 density in order to prepare offspring for different breeding densities. However, we found experimental support for the hypothesis that female yolk androgen allocation depends on mate attractiveness and that it constitutes an example of differential allocation. Females increased the concentration of androgens in their eggs when mated to males with experimentally elongated tails. Female phenotypic quality as measured by arrival date and clutch size was positively related to egg androgen concentration, consistent with the hypothesis that this is a costly investment, constrained by female condition. We found correlative evidence of a direct relationship between egg androgen concentration and performance of offspring as measured by mass increase.

  • gape coloration reliably reflects immunocompetence of barn swallow Hirundo Rustica nestlings
    Behavioral Ecology, 2003
    Co-Authors: Nicola Saino, Roberto Ambrosini, Paola Ninni, Roberta Martinelli, Anders Pape Moller
    Abstract:

    In some passerines, parents allocate more food to offspring with the brightest red gapes, but the function of parental decisions based on offspring gape coloration is unknown. We hypothesize that gape coloration is part of a communication system where nestlings reveal their condition to attending parents, which may thus base their decisions on reliable signals of offspring reproductive value. We analyze the effects of brood size manipulation, injection with an immunogen and food deprivation, on gape coloration, morphology, and T-cell--mediated immunocompetence of nestling barn swallows (Hirundo Rustica). For each gape we measured three components of coloration (hue, saturation, and brightness) and obtained an overall color score by principal component analysis. Enlargement of brood size and injection with an antigen resulted in less red and less saturated and brighter gape color. Nestlings in enlarged broods had smaller body mass and T-cell--mediated immunocompetence compared to those in reduced broods. A positive covariation existed between redness and saturation of gape color and T-cell--mediated immunocompetence. Gape color siblings raised in different nests did not depend on parentage. Thus, condition-dependent gape coloration can reveal different components of nestling state on which parents may base their adaptive decisions about allocation of care to the offspring. Copyright 2003.

  • structural coloration and sexual selection in the barn swallow Hirundo Rustica
    Behavioral Ecology, 2002
    Co-Authors: Claire Perrier, Anders Pape Moller, Florentino De Lope, Paola Ninni
    Abstract:

    Structural coloration has been hypothesized to play a role in sexual selection, and we tested whether this was the case in a field study of the barn swallow Hirundo Rustica. The dorsal iridescent plumage of barn swallows has a strong reflectance in the ultraviolet (UV) region, with adult males on average reflecting 8-9% more than adult females, as revealed by a 2-year study in southwestern Spain. The correlation between structural coloration (described by the reflectance in the UV part of the spectrum, UV chroma and blue chroma) and three other secondary sexual characters significantly associated with male mating success (tail length, tail asymmetry, and red facial coloration) was weak and generally nonsignificant. Nor was there a significant relationship between color parameters and body condition. We tested for an association between structural coloration of the dorsal plumage and sexual selection in a number of independent tests. Arrival date of males was not significantly related to color; there was no significant relationship between coloration and probability of survival or age; mated males did not have stronger reflectance than unmated males; and the duration of the premating period was not significantly related to color. Reproductive success was not significantly correlated with plumage coloration in males, nor was the feeding rate of offspring by brightly colored males higher than that of males with less bright plumage. Given that sample sizes were large, and the power of statistical tests high, we conclude that current sexual selection on the coloration of the dorsal plumage in the barn swallow is, at best, weak. Copyright 2002.

  • begging and parental care in relation to offspring need and condition in the barn swallow Hirundo Rustica
    The American Naturalist, 2000
    Co-Authors: Nicola Saino, Paola Ninni, Michele Incagli, Stefano Calza, Roberto Sacchi, Anders Pape Moller
    Abstract:

    abstract: Parents are selected to maximize their fitness by allocating care among their progeny in relation to the differential reproductive value of offspring. Nestlings have been hypothesized to signal need for parental care reliably through their begging behavior, but offspring condition as reflected by their reproductive value may likewise affect begging and hence provisioning. We assessed the relative importance of need and condition in determining begging behavior and feeding rate of nestling barn swallows (Hirundo Rustica) through short‐term starvation, a challenge to their immune system with a foreign antigen negatively affecting condition, and brood size manipulation. Food deprivation but not condition or brood size manipulation increased nestling begging rate. Parents fed offspring depending on both need and condition but only when feeding broods that were reduced or of normal size. In enlarged broods, offspring received less food per capita than in reduced broods, and parents did not discrimina...

  • carotenoid plasma concentration immune profile and plumage ornamentation of male barn swallows Hirundo Rustica
    The American Naturalist, 1999
    Co-Authors: Nicola Saino, Riccardo Stradi, Paola Ninni, Elena Pini, Anders Pape Moller
    Abstract:

    abstract: Carotenoids exert immunomodulating, immunostimulating, and antioxidant actions in mammals and are major determinants of coloration in animals. Honest advertisement models of sexual selection propose that male ornaments, including coloration, are reliable indicators of male quality. Because of their simultaneous effects on male coloration and immunity, carotenoids might mediate the hypothesized relationship between the expression of epigamic coloration and parasitism in vertebrates. We analyzed the relationship between immune profile and concentration of lutein, the most abundant carotenoid in the plasma of male barn swallows (Hirundo Rustica). Consistent with our predictions, lutein plasma concentration was negatively correlated with gamma‐globulin plasma levels and concentration of selected leukocyte types in peripheral blood, suggesting that, to exert immune function, carotenoids are taken up from plasma, thus becoming unavailable for epigamic signaling. The coloration of red feathers of the t...