scholarly journals Pre- and post-copulatory traits working in concert: sexual dichromatism in passerines is associated with sperm morphology

2020 ◽  
Vol 16 (1) ◽  
pp. 20190568
Author(s):  
Kate L. Durrant ◽  
Tom Reader ◽  
Matthew R. E. Symonds
Keyword(s):  
Sexual Selection ◽  
Sexual Dichromatism ◽  
Trade Off ◽  
Male Plumage ◽  
Negative Trait ◽  
Sperm Midpiece ◽  
Costly Traits ◽  
Phylogenetic Regression ◽  
Positive Covariance ◽  
Sperm Traits

Passerine birds produce costly traits under intense sexual selection, including elaborate sexually dichromatic plumage and sperm morphologies, to compete for fertilizations. Plumage and sperm traits vary markedly among species, but it is unknown if this reflects a trade-off between pre- and post-copulatory investment under strong sexual selection producing negative trait covariance, or variation in the strength of sexual selection among species producing positive covariance. Using phylogenetic regression, we analysed datasets describing plumage and sperm morphological traits for 278 passerine species. We found a significant positive relationship between sperm midpiece length and male plumage elaboration and sexual dichromatism. We did not find a relationship between plumage elaboration and testes mass. Our results do not support a trade-off between plumage and sperm traits, but may be indicative of variance among species in the strength of sexual selection to produce both brightly coloured plumage and costly sperm traits.

scholarly journals Trade-off between carotenoid-based sexual ornamentation and sperm resistance to oxidative challenge

2017 ◽  
Vol 284 (1847) ◽  
pp. 20162444 ◽  
Author(s):  
Oldřich Tomášek ◽  
Jana Albrechtová ◽  
Martina Němcová ◽  
Pavlína Opatová ◽  
Tomáš Albrecht
Keyword(s):  
Redox Homeostasis ◽  
Sperm Velocity ◽  
Trade Off ◽  
Competition Theory ◽  
Oxidative Challenge ◽  
Sperm Midpiece ◽  
Sperm Morphometry ◽  
Sexual Ornamentation ◽  
Sperm Traits

It has been hypothesized that carotenoid-based sexual ornamentation signals male fertility and sperm competitive ability as both ornamentation and sperm traits may be co-affected by oxidative stress, resulting in positive covariation (the ‘redox-based phenotype-linked fertility hypothesis’; redox-based PLFH). On the other hand, the ‘sperm competition theory’ (SCT) predicts a trade-off between precopulatory and postcopulatory traits. Here, we manipulate oxidative status (using diquat dibromide) and carotenoid availability in adult zebra finch ( Taeniopygia guttata ) males in order to test whether carotenoid-based beak ornamentation signals, or is traded off against, sperm resistance to oxidative challenge. Initial beak colouration, but not its change during the experiment, was associated with effect of oxidative challenge on sperm velocity, such that more intense colouration predicted an increase in sperm velocity under control conditions but a decline under oxidative challenge. This suggests a long-term trade-off between ornament expression and sperm resistance to oxidative challenge. Shortening of the sperm midpiece following oxidative challenge further suggests that redox homeostasis may constrain sperm morphometry. Carotenoid supplementation resulted in fewer sperm abnormalities but had no effect on other sperm traits. Overall, our data challenge the redox-based PLFH, partially support the SCT and highlight the importance of carotenoids for normal sperm morphology.

scholarly journals Absence of reproduction-immunity trade-off in male Drosophila melanogaster evolving under differential sexual selection

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Zeeshan Ali Syed ◽  
Vanika Gupta ◽  
Manas Geeta Arun ◽  
Aatashi Dhiman ◽  
Bodhisatta Nandy ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Sexual Selection ◽  
Trade Off

scholarly journals Plumage iridescence is associated with distinct feather microbiota in a tropical passerine

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Veronika Gvoždíková Javůrková ◽  
Erik D. Enbody ◽  
Jakub Kreisinger ◽  
Kryštof Chmel ◽  
Jakub Mrázek ◽  
...  
Keyword(s):  
Sexual Selection ◽  
Community Structure ◽  
Microbial Communities ◽  
Plumage Coloration ◽  
Microbial Load ◽  
Sexual Dichromatism ◽  
Physiological Processes ◽  
Fitness Consequences ◽  
Future Work

Abstract Birds present a stunning diversity of plumage colors that have long fascinated evolutionary ecologists. Although plumage coloration is often linked to sexual selection, it may impact a number of physiological processes, including microbial resistance. At present, the degree to which differences between pigment-based vs. structural plumage coloration may affect the feather microbiota remains unanswered. Using quantitative PCR and DGGE profiling, we investigated feather microbial load, diversity and community structure among two allopatric subspecies of White-shouldered Fairywren, Malurus alboscapulatus that vary in expression of melanin-based vs. structural plumage coloration. We found that microbial load tended to be lower and feather microbial diversity was significantly higher in the plumage of black iridescent males, compared to black matte females and brown individuals. Moreover, black iridescent males had distinct feather microbial communities compared to black matte females and brown individuals. We suggest that distinctive nanostructure properties of iridescent male feathers or different investment in preening influence feather microbiota community composition and load. This study is the first to point to structural plumage coloration as a factor that may significantly regulate feather microbiota. Future work might explore fitness consequences and the role of microorganisms in the evolution of avian sexual dichromatism, with particular reference to iridescence.

scholarly journals A trade-off between natural and sexual selection underlies diversification of a sexual signal

2014 ◽  
Vol 26 (2) ◽  
pp. 533-542 ◽  
Author(s):  
Justa L. Heinen-Kay ◽  
Kirstin E. Morris ◽  
Nicole A. Ryan ◽  
Samantha L. Byerley ◽  
Rebecca E. Venezia ◽  
...  
Keyword(s):  
Sexual Selection ◽  
Sexual Signal ◽  
Trade Off ◽  
Natural And Sexual Selection

scholarly journals Are attractive male crickets better able to pay the costs of an immune challenge?

2015 ◽  
Author(s):  
Clint D Kelly ◽  
Melissa Telemeco ◽  
Amy L Toth ◽  
Lyric C Bartholomay
Keyword(s):  
Sexual Selection ◽  
Immune Activation ◽  
Immune Challenge ◽  
Trade Off ◽  
Gryllus Texensis ◽  
Field Crickets ◽  
Sexual Display ◽  
The Face ◽  
Future Reproduction ◽  
Attractive Male

Reproduction and immunity are fitness-related traits that trade-off with each other. Parasite-mediated theories of sexual selection suggest, however, that higher-quality males should suffer smaller costs to reproduction-related traits and behaviours (e.g. sexual display) from an immune challenge because these males possess more resources with which to deal with the challenge. We used Gryllus texensis field crickets to test the prediction that attractive males should better maintain the performance of a fitness-related traits (e.g. calling effort) in the face of an immune challenge compared with unattractive males. We found no support for our original predictions. However, that immune activation causes attractive males to significantly increase their calling effort compared with unattractive males suggests that these males might terminally invest in order to compensate for decreased future reproduction.

scholarly journals Female and male plumage colour is linked to parental quality, pairing and extra-pair mating in a tropical passerine

2020 ◽  
Author(s):  
Ana V. Leitão ◽  
Michelle L. Hall ◽  
Raoul A. Mulder
Keyword(s):  
Sexual Selection ◽  
Phenotypic Traits ◽  
Plumage Colour ◽  
Honest Signal ◽  
Sexual Competition ◽  
Extra Pair Paternity ◽  
Parental Quality ◽  
Male Plumage ◽  
Pair Mating ◽  
Extra Pair Mating

ABSTRACTSexual selection has been proposed to drive the evolution of elaborate phenotypic traits in males, which often confer success in competition or mating. However, in many species both males and females display such traits, although studies reporting selection acting in both sexes are scarce. In this study, we investigated whether plumage ornamentation is sexually selected in female and male lovely fairy-wrens Malurus amabilis, a cooperatively breeding songbird. We found that female and male plumage colour was correlated with parental quality but did not incur survival costs. We also found evidence of positive assortative mating based on plumage colour. Microsatellite analyses of paternity indicated that the lovely fairywren has high levels of extra-pair paternity, with 53% of offspring resulting from extra-pair mating. Female and male plumage colour did not predict reproductive success and female proportion of extra-pair offspring in its own nest, but less colourful males obtained higher extra-pair paternity. We argue that plumage colour may be under sex-specific selection, highlighting the importance of looking at both sexes in studies of sexual selection and ornament evolution. The current findings together with previous study, suggest that plumage colour in female and male lovely fairy-wrens appears to be an honest signal relevant in both intra and inter-sexual competition contexts.

scholarly journals Migration and the evolution of sexual dichromatism: evolutionary loss of female coloration with migration among wood-warblers

2015 ◽  
Vol 282 (1809) ◽  
pp. 20150375 ◽  
Author(s):  
Richard K. Simpson ◽  
Michele A. Johnson ◽  
Troy G. Murphy
Keyword(s):  
Sexual Selection ◽  
Sexual Dichromatism ◽  
Ancestral State ◽  
Migration Distance ◽  
Female Ornamentation ◽  
Wood Warblers ◽  
Selection For ◽  
Evolution Of Migration ◽  
And Migration ◽  
Female Coloration

The mechanisms underlying evolutionary changes in sexual dimorphism have long been of interest to biologists. A striking gradient in sexual dichromatism exists among songbirds in North America, including the wood-warblers (Parulidae): males are generally more colourful than females at northern latitudes, while the sexes are similarly ornamented at lower latitudes. We use phylogenetically controlled comparative analysis to test three non-mutually exclusive hypotheses for the evolution of sexual dichromatism among wood-warblers. The first two hypotheses focus on the loss of female coloration with the evolution of migration, either owing to the costs imposed by visual predators during migration, or owing to the relaxation of selection for female social signalling at higher latitudes. The third hypothesis focuses on whether sexual dichromatism evolved owing to changes in male ornamentation as the strength of sexual selection increases with breeding latitude. To test these hypotheses, we compared sexual dichromatism to three variables: the presence of migration, migration distance, and breeding latitude. We found that the presence of migration and migration distance were both positively correlated with sexual dichromatism, but models including breeding latitude alone were not strongly supported. Ancestral state reconstruction supports the hypothesis that the ancestral wood-warblers were monochromatic, with both colourful males and females. Combined, these results are consistent with the hypotheses that the evolution of migration is associated with the relaxation of selection for social signalling among females and that there are increased predatory costs along longer migratory routes for colourful females. These results suggest that loss of female ornamentation can be a driver of sexual dichromatism and that social or natural selection may be a stronger contributor to variation in dichromatism than sexual selection.

scholarly journals Sexual selection, range size and population size

2012 ◽  
Vol 20 (1) ◽  
pp. 1-25 ◽  
Author(s):  
Anders Pape Møller ◽  
László Zsolt Garamszegi
Keyword(s):  
Sexual Selection ◽  
Population Size ◽  
Extinction Risk ◽  
Range Size ◽  
Sexual Dichromatism ◽  
Common Descent ◽  
Distribution Limits ◽  
Western Palaearctic ◽  
Linear Contrasts ◽  
Average Fitness

Abstract Sexual selection may impose fitness costs on both males and females due to the costs of developing and maintaining exaggerated sexual signals, reducing average fitness in strongly sexually selected species. Such reductions in average fitness could affect local extinction risk and hence distribution range. However, given that both sexually monochromatic and dichromatic species are common and widespread, benefits of sexual selection must be invoked to maintain equilibrium. We tested for differences in breeding range size and population size between monochromatic and dichromatic species of birds in a comparative analysis of species from the Western Palaearctic. In an analysis of standardized linear contrasts of the relationship between sexual dichromatism and range size and population size, respectively, that controlled for similarity among taxa due to common descent, we found no significant relationship. However, when we analyzed carotenoid-based sexual dichromatism sexually dichromatic species had larger distribution areas and higher northernmost distribution limits, but not southernmost distribution limits than sexually monochromatic species. In contrast, melanin-based sexual dichromatism was not significantly associated with range size or population size. Therefore, population density of sexually dichromatic species with carotenoid-based coloration was lower than that of monochromatic species, because dichromatic species had similar population sizes but larger ranges than monochromatic species. These findings suggest that the different physiological roles of pigments associated with sexual dichromatism have effects on total range size of birds.

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