scholarly journals Microstructures amplify carotenoid plumage signals in colorful tanagers

2019 ◽  
Author(s):  
Dakota E. McCoy ◽  
Allison J. Shultz ◽  
Charles Vidoudez ◽  
Emma van der Heide ◽  
Sunia A. Trauger ◽  
...  
Keyword(s):  
Optical Power ◽  
Sexually Dimorphic ◽  
Carotenoid Pigment ◽  
Liquid Chromatography Mass Spectrometry ◽  
Optical Modeling ◽  
Honest Signals ◽  
The Social ◽  
Males And Females ◽  
Saturated Color ◽  
Difference Time

AbstractRed, orange, and yellow carotenoid-colored plumages have been considered honest signals of condition. We comprehensively quantified carotenoid signals in the social, sexually-dimorphic tanager genus Ramphocelus using scanning electron microscopy (SEM), finite-difference time-domain (FDTD) optical modeling, liquid chromatography–mass spectrometry (LC-MS), and spectrophotometry. Despite males having significantly more saturated color patches, males and females within a species have equivalent amounts and types of carotenoids. Male, but not female, feathers have elaborate microstructures which amplify color appearance. Expanded barbs enhance color saturation (for the same amount of pigment) by increasing the transmission of optical power through the feather. Dihedral barbules (vertically-angled, strap-shaped barbules) reduce total reflectance to generate “super black” plumage, an optical illusion to enhance nearby color. Dihedral barbules paired with red carotenoid pigment produce “velvet red” plumage. Together, our results suggest that a widely cited index of honesty—carotenoid pigments—cannot fully explain male appearance. We propose that males are selected to evolve amplifiers of honest signals—in this case, microstructures that enhance appearance —that are not necessarily themselves linked to quality.

scholarly journals Microstructures amplify carotenoid plumage signals in tanagers

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dakota E. McCoy ◽  
Allison J. Shultz ◽  
Charles Vidoudez ◽  
Emma van der Heide ◽  
Jacqueline E. Dall ◽  
...  
Keyword(s):  
Optical Power ◽  
Sexually Dimorphic ◽  
Carotenoid Pigments ◽  
Carotenoid Pigment ◽  
Optical Modeling ◽  
Honest Signals ◽  
The Social ◽  
Color Differences ◽  
Saturated Color ◽  
Difference Time

AbstractBrilliantly-colored birds are a model system for research into evolution and sexual selection. Red, orange, and yellow carotenoid-colored plumages have been considered honest signals of condition; however, sex differences in feather pigments and microstructures are not well understood. Here, we show that microstructures, rather than carotenoid pigments, seem to be a major driver of male–female color differences in the social, sexually-dimorphic tanager genus Ramphocelus. We comprehensively quantified feather (i) color (using spectrophotometry), (ii) pigments (using liquid chromatography–mass spectrometry (LC–MS)), and (iii) microstructures (using scanning electron microscopy (SEM) and finite-difference time-domain (FDTD) optical modeling). Males have significantly more saturated color patches than females. However, our exploratory analysis of pigments suggested that males and females have concordant carotenoid pigment profiles across all species (MCMCglmm model, female:male ratio = 0.95). Male, but not female, feathers have elaborate microstructures which amplify color appearance. Oblong, expanded feather barbs in males enhance color saturation (for the same amount of pigment) by increasing the transmission of optical power through the feather. Dihedral barbules (vertically-angled, strap-shaped barbules) in males reduce total reflectance to generate “super black” and “velvet red” plumage. Melanin in females explains some, but not all, of the male–female plumage differences. Our results suggest that a widely cited index of honesty, carotenoid pigments, cannot fully explain male appearance. We propose that males are selected to evolve amplifiers—in this case, microstructures that enhance appearance—that are not necessarily themselves linked to quality.

scholarly journals Heightened condition dependent expression of structural colouration in the faces, but not wings, of male and female flies

2021 ◽  
Author(s):  
Thomas E White ◽  
Amy Locke ◽  
Tanya Latty
Keyword(s):  
Mate Choice ◽  
Condition Dependence ◽  
Sexually Dimorphic ◽  
Male And Female ◽  
Honest Signals ◽  
Mutual Mate Choice ◽  
Close Range ◽  
Males And Females ◽  
Structural Colouration

Abstract Structurally coloured sexual signals are a conspicuous and widespread class of ornament used in mate choice, though the extent to which they encode information on the quality of their bearers is not fully resolved. Theory predicts that signalling traits under strong sexual selection as honest indicators should evolve to be more developmentally integrated and exaggerated than nonsexual traits, thereby leading to heightened condition dependence. Here we test this prediction through examination of the sexually dimorphic faces and wings of the cursorial fly Lispe cana. Males and females possess structural UV-white and golden faces, respectively, and males present their faces and wings to females during close-range, ground-based courtship displays, thereby creating the opportunity for mutual inspection. Across a field-collected sample of individuals, we found that the appearance of the faces of both sexes scaled positively with individual condition, though along separate axes. Males in better condition expressed brighter faces as modelled according to conspecific flies, whereas condition scaled with facial saturation in females. We found no such relationships for their wing interference pattern nor abdomens, with the latter included as a nonsexual control. Our results suggest that the structurally coloured faces, but not the iridescent wings, of male and female Lispe cana are reliable guides to individual quality and support the broader potential for structural colours as honest signals. They also highlight the potential for mutual mate choice in this system, while arguing for one of several alternate signalling roles for wing interferences patterns among the myriad taxa which bear them.

scholarly journals Heightened condition dependent expression of structural colouration in the faces, but not wings, of male and female flies

2021 ◽  
Author(s):  
Thomas E White ◽  
Amy Locke ◽  
Tanya Latty
Keyword(s):  
Mate Choice ◽  
Condition Dependence ◽  
Sexually Dimorphic ◽  
Male And Female ◽  
Honest Signals ◽  
Mutual Mate Choice ◽  
Close Range ◽  
Males And Females ◽  
Structural Colouration

Structurally coloured sexual signals are a conspicuous and widespread class of ornament used in mate choice, though the extent to which they encode information on the quality of their bearers is not fully resolved. Theory predicts that signalling traits under strong sexual selection as honest indicators should evolve to be more developmentally integrated and exaggerated than nonsexual traits, thereby leading to heightened condition dependence. Here we test this prediction through examination of the sexually dimorphic faces and wings of the cursorial fly Lispe cana. Males and females possess structural UV-white and golden faces, respectively, and males present their faces and wings to females during close-range, ground-based courtship displays, thereby creating the opportunity for mutual inspection. Across a field-collected sample of individuals, we found that the appearance of the faces of both sexes scaled positively with individual condition, though along separate axes. Males in better condition expressed brighter faces as modelled according to conspecific flies, whereas condition scaled with facial saturation in females. We found no such relationships for their wing interference pattern nor abdomens, with the latter included as a nonsexual control. Our results suggest that the structurally coloured faces, but not the iridescent wings, of male and female Lispe cana are reliable guides to individual quality and support the broader potential for structural colours as honest signals. They also highlight the potential for mutual mate choice in this system, while arguing for one of several alternate signalling roles for wing interferences patterns among the myriad taxa which bear them.

Dispersal patterns in a regional koala population in south-east Queensland

2003 ◽  
Vol 30 (3) ◽  
pp. 281 ◽  
Author(s):  
David S. Dique ◽  
Jim Thompson ◽  
Harriet J. Preece ◽  
Deidré L. de Villiers ◽  
Frank N. Carrick
Keyword(s):  
Urban Areas ◽  
Home Ranges ◽  
Adult Males ◽  
Dispersal Patterns ◽  
Young Males ◽  
Straight Line ◽  
The Social ◽  
Straight Line Distance ◽  
Males And Females ◽  
Natal Home

Koala dispersal was investigated as part of a detailed ecological study of a nationally significant koala population located 20 km south-east of Brisbane, Queensland. From 1996 to 2000, 195 koalas from three sites were captured and fitted with radio-collars. A total of 40 koalas (23 males and 17 females) dispersed from these sites. Most (93%) dispersing individuals were 20–36 months of age. Three adult females (more than 36 months old) dispersed and no adult males dispersed during the study. A significantly higher proportion of young males dispersed than females. Dispersal occurred between June and December, with most dispersal of males commencing in July and August and that of females commencing between September and November prior to, and early in, the annual breeding season. The mean straight-line distance between the natal and breeding home ranges for males and females was similar and was measured at 3.5 km (range 1.1–9.7 km) and 3.4 km (range 0.3–10.6 km) respectively. Dispersing males and females tended to successfully disperse south and west of their natal home ranges and were generally unable to successfully disperse to urban areas within the study area, as a high proportion of the mortality of dispersing koalas was associated with attacks by domestic dogs and with collisions with vehicles on roads. Information from other studies indicates that most young koalas disperse from their natal areas. It is likely that the social behaviour and mating systems of koala populations provide mechanisms for young koalas to disperse. The potential role of dispersal in the dynamics of regional koala populations is discussed.

Social experience influences preferences in black ducks and mallards

1989 ◽  
Vol 67 (6) ◽  
pp. 1434-1438 ◽  
Author(s):  
Lynn M. Brodsky ◽  
C. Davison Ankney ◽  
Darrell G. Dennis
Keyword(s):  
Social Preferences ◽  
Anas Platyrhynchos ◽  
Social Experience ◽  
The Other ◽  
Captive Population ◽  
Male And Female ◽  
Potential Mate ◽  
The Social ◽  
Opposite Sex ◽  
Males And Females

The influence of social experience on the preferences for a potential mate in a captive population of black ducks, Anas rubripes, and mallards, Anas platyrhynchos, was examined. Birds were reared from hatching with conspecifics (i.e., female black ducks with male black ducks, female mallards with male mallards), or were cross-fostered with the other species (i.e., female black ducks with male mallards, female mallards with male black ducks). Preferences of individuals were tested in a chamber containing caged black ducks and mallards of the opposite sex. In over 90% (100/109) of the trials, males and females preferred the species that they were raised with since hatching, whether they were of the same species or not. These results demonstrate that social experience influences the social preferences of male and female black ducks and mallards.

Sex differences in melanotic encapsulation responses (immunocompetence) in the damselfly Lestes forcipatus Rambur

2002 ◽  
Vol 80 (9) ◽  
pp. 1578-1583 ◽  
Author(s):  
Christopher P Yourth ◽  
Mark R Forbes ◽  
Robert L Baker
Keyword(s):  
Sex Differences ◽  
Immune Responses ◽  
Life Histories ◽  
Mass Gain ◽  
Sexually Dimorphic ◽  
Foreign Objects ◽  
Males And Females ◽  
And Gender ◽  
Parasitic Mites ◽  
Melanotic Encapsulation

A few studies have shown that male and female invertebrates differ in immunity and that these differences appear related to differences in sexual dimorphism and gender differences in life histories. Melanotic encapsulation of foreign objects in insects is one form of immunity. The damselfly Lestes forcipatus Rambur is moderately sexually dimorphic, and much is known about patterns of mass gain in congeners relating to differences in life history between males and females. In this study, females were more immunoresponsive than males under controlled temperatures, following emergence, and at a time when parasitic mites were challenging these hosts. However, males and females that overlapped in mass at emergence did not differ in their immune responses. Males in better condition at emergence were more immunoresponsive than lighter males, but this relation was not found in females. Sex differences in immune expression may have implications for how females versus males are able to deal with challenges from parasites, under varying environmental conditions.

scholarly journals Prenatal Risk for Autism Spectrum Disorder (ASD): Fetal Cortisol Exposure Predicts Child ASD Symptoms

2018 ◽  
Vol 7 (2) ◽  
pp. 349-361 ◽  
Author(s):  
Sheena Ram ◽  
Mariann A. Howland ◽  
Curt A. Sandman ◽  
Elysia Poggi Davis ◽  
Laura M. Glynn
Keyword(s):  
Autism Spectrum Disorder ◽  
Developmental Disorder ◽  
Maternal Plasma ◽  
Autism Spectrum ◽  
Spectrum Disorder ◽  
Sexually Dimorphic ◽  
Fetal Exposure ◽  
Prospective Longitudinal Study ◽  
The Social ◽  
Prospective Longitudinal

The etiology of autism spectrum disorder (ASD) is multifactorial, complex, and likely involves interactions among genetic, epigenetic, and environmental factors. With respect to environmental influences, a growing literature implicates intrauterine experiences in the origin of this pervasive developmental disorder. In this prospective longitudinal study, we examined the hypothesis that fetal exposure to maternal cortisol may confer ASD risk. In addition, because ASD is four times more prevalent in males than in females, and because sexually dimorphic responses to intrauterine experiences are commonly observed, we examined whether or not any associations differ by fetal sex. Maternal plasma cortisol was measured at 15, 19, 25, 31, and 37 weeks’ gestation in a sample of 84 pregnant women. ASD symptoms were assessed in their 5-year-old children with the Social Communication Questionnaire (SCQ). Fetal exposure to lower levels of maternal cortisol was associated with higher levels of ASD symptoms only among boys. The observed hypocortisolemic profile exhibited by these mothers may indicate a risk factor that precedes the stress of caregiving for a child with ASD and may not be solely a consequence of the stress of caregiving, as previously thought. These findings confirm the value of examining prenatal hormone exposures as predictors of ASD risk and support the premise that altered prenatal steroid exposures may play a role in the etiology of ASD.

scholarly journals Sex identification in embryos and adults of Darwin’s finches

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0237687
Author(s):  
Mariya P. Dobreva ◽  
Joshua G. Lynton-Jenkins ◽  
Jaime A. Chaves ◽  
Masayoshi Tokita ◽  
Camille Bonneaud ◽  
...  
Keyword(s):  
Field Studies ◽  
Sexually Dimorphic ◽  
Genetic Studies ◽  
Darwin's Finches ◽  
Darwin’S Finches ◽  
Specific Morphology ◽  
Males And Females ◽  
Primer Sets ◽  
Dimorphic Species ◽  
Source Of Error

Darwin’s finches are an iconic example of adaptive radiation and evolution under natural selection. Comparative genetic studies using embryos of Darwin’s finches have shed light on the possible evolutionary processes underlying the speciation of this clade. Molecular identification of the sex of embryonic samples is important for such studies, where this information often cannot be inferred otherwise. We tested a fast and simple chicken embryo protocol to extract DNA from Darwin’s finch embryos. In addition, we applied minor modifications to two of the previously reported PCR primer sets for CHD1, a gene used for sexing adult passerine birds. The sex of all 29 tested embryos of six species of Darwin’s finches was determined successfully by PCR, using both primer sets. Next to embryos, hatchlings and fledglings are also impossible to distinguish visually. This extends to juveniles of sexually dimorphic species which are yet to moult in adult-like plumage and beak colouration. Furthermore, four species of Darwin’s finches are monomorphic, males and females looking alike. Therefore, sex assessment in the field can be a source of error, especially with respect to juveniles and mature monomorphic birds outside of the mating season. We caught 567 juveniles and adults belonging to six species of Darwin’s finches and only 44% had unambiguous sex-specific morphology. We sexed 363 birds by PCR: individuals sexed based on marginal sex specific morphological traits; and birds which were impossible to classify in the field. PCR revealed that for birds with marginal sex specific traits, sexing in the field produced a 13% error rate. This demonstrates that PCR based sexing can improve field studies on Darwin’s finches, especially when individuals with unclear sex-related morphology are involved. The protocols used here provide an easy and reliable way to sex Darwin’s finches throughout ontogeny, from embryos to adults.

Learners’ Knowledge of Local History and Culture

2021 ◽  
Vol 1 (1) ◽  
pp. 57-62
Author(s):  
Charle F. Ysulan
Keyword(s):  
Public Schools ◽  
Family Income ◽  
Local History ◽  
School Year ◽  
The Social ◽  
Sex Type ◽  
Males And Females ◽  
Spss Software ◽  
Type Of School ◽  
One Way Anova

This descriptive study determined the learners' knowledge of local history and culture. The participants were Grade 10 students enrolled for the school year 2018-2019, categorized according to sex, type of school, and family income. The data were tabulated and analyzed using SPSS (Software Package for the Social Sciences Software) with Frequency, Mean, Standard Deviation, t-Test, and One-way ANOVA. The findings demonstrated that when learners were categorized by sex, type of school, and family income, their knowledge of local history was partly knowledgeable. When taken as a whole, the learners' knowledge of local culture was also partly knowledgeable. Both males and females were partly knowledgeable when it came to sex. In terms of the type of school, public schools were knowledgeable, whereas private schools were only partly knowledgeable. Finally, when it came to family income, learners with low and average family income were partly knowledgeable, whereas learners with high family income were knowledgeable. With this study, learners' knowledge gained knowledge of local history and culture.

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