| stress response, gut microbial diversity and sexual signals correlate with social interactions. | theory predicts that social interactions are dynamically linked to phenotype. yet because social interactions are difficult to quantify, little is known about the precise details on how interactivity is linked to phenotype. here, we deployed proximity loggers on north american barn swallows (hirundo rustica erythrogaster) to examine intercorrelations among social interactions, morphology and features of the phenotype that are sensitive to the social context: stress-induced corticosterone (cort) ... | 2016 | 27354713 |
| multimodal signalling in the north american barn swallow: a phenotype network approach. | complex signals, involving multiple components within and across modalities, are common in animal communication. however, decomposing complex signals into traits and their interactions remains a fundamental challenge for studies of phenotype evolution. we apply a novel phenotype network approach for studying complex signal evolution in the north american barn swallow (hirundo rustica erythrogaster). we integrate model testing with correlation-based phenotype networks to infer the contributions o ... | 2015 | 26423842 |
| quantitative genetics of plumage color: lifetime effects of early nest environment on a colorful sexual signal. | phenotypic differences among individuals are often linked to differential survival and mating success. quantifying the relative influence of genetic and environmental variation on phenotype allows evolutionary biologists to make predictions about the potential for a given trait to respond to selection and various aspects of environmental variation. in particular, the environment individuals experience during early development can have lasting effects on phenotype later in life. here, we used a n ... | 2015 | 26380676 |
| performance of encounternet tags: field tests of miniaturized proximity loggers for use on small birds. | proximity logging is a new tool for understanding social behavior as it allows for accurate quantification of social networks. we report results from field calibration and deployment tests of miniaturized proximity tags (encounternet), digital transceivers that log encounters between tagged individuals. we examined radio signal behavior in relation to tag attachment (tag, tag on bird, tag on saline-filled balloon) to understand how radio signal strength is affected by the tag mounting technique ... | 2015 | 26348329 |
| 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 ... | 2014 | 25461975 |
| 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 ... | 2014 | 25056627 |
| 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 ... | 2013 | 24013040 |
| 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 ... | 2013 | 23966597 |
| 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 ... | 2011 | 21949464 |
| 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 ... | 2011 | 21853105 |
| 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. | 2010 | 20195540 |
| 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) ... | 2005 | 17148214 |