Sexual signals such as colour ornamentation and birdsong evolve independently of each other in some clades, and in others they evolve positively or negatively correlated. We rarely know why correlated evolution does or does not occur. Here, we show positively correlated evolution between plumage colour and song motor performance among canaries, goldfinches and allies, associated with species differences in body size.
View Article and Find Full Text PDFBullying consists of preferentially attacking individuals lowest in the dominance hierarchy, and its functions are unclear because the most subordinate individuals do not pose social challenges to the aggressor. Instead, conflict is expected mostly between individuals of similar dominance rank or socially distant (i.e.
View Article and Find Full Text PDFThe oxytocin family of neuropeptides is implicated in the regulation of sociality across vertebrates. Non-mammalian homologs of oxytocin, such as isotocin in fish and mesotocin in amphibians, reptiles and birds, all play crucial roles modulating social and reproductive behavior. In this study, we exogenously manipulated the mesotocinergic system in a highly social bird, the common waxbill Estrild astrild, and tested the effects on affiliative and aggressive behavior by performing tests of competition over food.
View Article and Find Full Text PDFCarotenoid-based colour signals can be costly to produce and maintain, and trade-offs between signalling and other fitness traits are expected. In mutually ornamented species, trade-offs with reproduction may be stronger for females than males, because females often dedicate more resources to offspring production, which may lead to plastic investment in colour signals and plastic sexual dichromatism. Oestradiol is a candidate mediator of this trade-off because it regulates reproductive physiology and may also influence the expression of coloration.
View Article and Find Full Text PDFAbstractSexual ornamentation is often assumed to be costly, allowing honest signaling of individual quality, and carotenoid-based colors have been proposed to bear significant costs. If carotenoid-based colors are costly to produce, sexually selected signals should use more concentrated carotenoid pigments and have more saturated color than nonsexual signals, where honesty-guaranteeing costs are not required. We tested this prediction comparing carotenoid-based colors across canaries, goldfinches, and allies because many of these species use yellow plumage as sexual ornamentation but also have yellow rumps that appear to be nonsexual flash marks.
View Article and Find Full Text PDFThe dopaminergic (DAergic) system has well-known influences on behavioral and cognitive functions. Previous work with common waxbills (Estrilda astrild) reported context-specific DAergic effects that could have been due to social environment. Manipulating the dopamine D2-like receptor family (D2R) pathways had opposing effects on behavior depending on whether waxbills were tested alone or in a small cage with a mirror as a social stimulus.
View Article and Find Full Text PDFMorphology, habitat and various selective pressures (e.g. social and sexual selection) can influence the evolution of acoustic signals, but the relative importance of their effects is not well understood.
View Article and Find Full Text PDFSex differences in ornamentation are common and, in species with conventional sex roles, are generally thought of as stable, due to stronger sexual selection on males. Yet, especially in gregarious species, ornaments can also have non-sexual social functions, raising the possibility that observed sex differences in ornamentation are plastic. For example, females may invest in costly ornamentation more plastically, to protect body and reproductive ability in more adverse ecological conditions.
View Article and Find Full Text PDFSexual signals are archetypes of contingent evolution: hyper-diverse across species, often evolving fast and in unpredictable directions. It is unclear to which extent their evolutionary unpredictability weakens deterministic evolution, or takes place bounded by deterministic patterns of trait evolution. We compared the evolution of sound frequency in sexual signals (advertisement songs) and non-sexual social signals (calls) across > 500 genera of the crown songbird families.
View Article and Find Full Text PDFIn a healthy athlete, the caloric intake is sufficient for sports energy needs and body physiological functions, allowing a balance between energy availability, bone metabolism, and menstrual cycle. On the other hand, an imbalance caused by low energy availability due to a restrictive diet, eating disorders or long periods of energy expenditure leads to multisystemic deregulation favoring the essential functions of the body. This phenomenon, described as the female athlete triad, occurs in a considerable percentage of high-performance athletes, with harmful consequences for their future.
View Article and Find Full Text PDFAbstractTheory predicts that allometric constraints on sound production should be stronger for the lower frequencies of vocalizations than for the higher frequencies, which could originate from an allometry for sound frequency bandwidth. Using song recordings of approximately 1,000 passerine species (from >75% passerine genera), we show a significantly steeper allometry for the lower song frequencies than for the higher song frequencies, resulting in a positive allometry of frequency bandwidth: larger species can use wider bandwidths than smaller species. The bandwidth allometry exists in songbirds (oscines) but not in nonoscine passerines, indicating that it emerges from a combination of constraints to sound frequency production or transmission and the evolved behavior of oscines: unlike the narrow bandwidths of most nonoscine songs, the learned songs of oscines often use wide bandwidths that can be limited by both lower and upper constraints to sound frequency.
View Article and Find Full Text PDFIntroduction: Coronary artery calcium (CAC) scoring is used for both cardiovascular risk reclassification and as a gatekeeper for coronary computed tomography angiography (CCTA). The aims of this study were to assess to what extent CAC score results can reclassify the cardiovascular risk of patients without obstructive coronary artery disease (CAD) on CCTA, and to measure the proportion of these patients whose primary prevention medication is changed after the exam.
Methods: In a retrospective analysis of a multicenter registry of individuals who underwent CCTA for suspected CAD during a two-year period, the Systematic COronary Risk Evaluation (SCORE) and Multi-Ethnic Study of Atherosclerosis (MESA) risk scores were calculated for each individual.
Environmental changes caused by urbanization and noise pollution can have profound effects on acoustic communication. Many organisms use higher sound frequencies in urban environments with low-frequency noise, but the developmental and evolutionary mechanisms underlying these shifts are generally unknown. We used a common garden experiment to ask whether changes in minimum song frequency observed 30 years after a songbird colonized an urban environment are a consequence of behavioural flexibility.
View Article and Find Full Text PDFWhile vivid colours in sexual signals can provide information on individual quality, vivid colours in interspecific signals have been interpreted mostly as indicating species identity and maximizing signal detection. Here we investigate if colour differences in an interspecific signal could also indicate relevant aspects of individual quality because, similarly to sexual signalling, in interspecific communication it could sometimes be advantageous to assess individual quality. For example when interacting with cleaner species, clients should benefit from assessing which individual cleaners provide better service.
View Article and Find Full Text PDFThe diversity and the motor performance of birdsongs can both be sexually selected. In wood warblers, most species with high motor performance sing a greater proportion of trills, presumably to advertise performance, and thus have lower syllable diversity. We tested if this trade-off between motor performance and syllable diversity extends to canaries, goldfinches and allies, a clade with much longer and more varied songs.
View Article and Find Full Text PDFEnvironmental instability (i.e. environments changing often) can select fixed phenotypes because of the lag time of plastically adapting to environmental changes, known as the lag-time constraint.
View Article and Find Full Text PDFCoronary CT angiography (CTA) is currently considered a reliable method to exclude obstructive coronary artery disease (CAD) before valvular heart surgery in patients with low pretest probability. However, its role in excluding obstructive CAD before transcatheter aortic valve implantation (TAVI) is less well established. Single-center retrospective study where patients with severe symptomatic aortic stenosis underwent both CTA and invasive coronary angiography (ICA) as part of TAVI planning.
View Article and Find Full Text PDFClin Rev Allergy Immunol
December 2020
Systemic lupus erythematosus (SLE) is a chronic, autoimmune disease associated with major obstetrical complications such as gestational loss, preterm delivery, fetal growth restriction (FGR) and preeclampsia. Published literature is not consensual regarding the main risk factors for each of these outcomes. Our goal with this study was to determine the most important predictors for each of the main adverse pregnancy outcomes in this population.
View Article and Find Full Text PDFIntroduction: The CAD-RADS classification was recently introduced in an attempt to standardize coronary computed tomography angiography (CCTA) reports and to provide recommendations for further management. The aim of this study was to assess how additional cardiac investigations were being ordered before the introduction of the CAD-RADS classification in a tertiary hospital's CCTA reports.
Methods: We conducted a single-center retrospective analysis of 200 patients (103 women, mean age 59±13 years) who underwent CCTA for suspected or known coronary artery disease prior to the systematic introduction of the CAD-RADS classification in the reports.
Research in sexual selection assumes that individuals attempt to choose high-quality mates, and that sexual signals evolve to indicate high quality. But it may often be more important to instead discriminate and avoid low-quality mates, thus reducing the likelihood of large penalties in fitness. We show, using simulations, that avoidance of low-quality mates (i.
View Article and Find Full Text PDFExotic species can experience fast expansion in new environments, especially if they left their pathogens behind (Enemy Release hypothesis) or brought novel pathogens to the native competitors (Novel Weapon hypothesis). Common waxbills (Estrilda astrild) are native to sub-Saharan Africa and invaded west Iberia since the 1960s. Past haemosporidian parasite surveys at four locations in Portugal showed that waxbills can be infected with parasites, though with very low prevalence.
View Article and Find Full Text PDFR Soc Open Sci
February 2018
Anthropogenic noise is more intense at lower sound frequencies, which could decrease urban tolerance of animals with low-frequency vocalizations. Four large comparative studies tested whether anthropogenic noise filters bird species according to the sound frequencies they use and produced discrepant results. We reanalysed data from these studies to explain their different results.
View Article and Find Full Text PDFAlthough sexual ornamentation mediates reproductive isolation, comparative evidence does not support the hypothesis that stronger sexual selection promotes speciation. Prior analyses have neglected the possibility that decreases in ornamentation may also promote speciation, such that both increases and decreases in the strength of sexual selection and associated changes in ornamentation promote speciation. To test this hypothesis, we studied color ornamentation in one of the largest and fastest avian radiations, the estrildid finches.
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