scholarly journals Baseline corticosterone does not reflect iridescent plumage traits in female tree swallows

2018 ◽  
Author(s):  
Keneth Sarpong ◽  
Christine L. Madliger ◽  
Christopher M. Harris ◽  
Oliver P. Love ◽  
Stéphanie M. Doucet ◽  
...  
Keyword(s):  
Tree Swallows ◽  
Secondary Sexual Traits ◽  
Factors Affecting ◽  
Brood Rearing ◽  
Trade Offs ◽  
Female Tree ◽  
Baseline Corticosterone ◽  
Sexual Characteristics ◽  
The Relationship ◽  
Secondary Sexual

AbstractThe production of high quality secondary sexual traits can be constrained by trade-offs in the allocation of energy and nutrients with other metabolic activities, and is mediated by physiological processes. In birds, the factors influencing male plumage quality have been well studied; however, factors affecting female plumage quality are poorly understood. Furthermore, it remains uncertain which physiological traits mediate the relationship between body condition and ornaments. In this three-year study of after-second-year female tree swallows (Tachycineta bicolor), we investigated (1) the relationship between baseline corticosterone near the end of the brood-rearing period (CORTBR) and feather colour characteristics (hue, saturation, brightness) the following year, and (2) the relationship between baseline corticosterone measured during incubation (CORTI) and brood rearing (CORTBR), and feather colour in the same year. To control for reproductive effort, we included reproductive parameters as covariates in all analyses. In this first study between CORT and the plumage colour characteristics of a species bearing iridescent feathers, we did not find any relationship between CORTBRand the colour of subsequently-produced feathers, nor did we find any relationship between CORTIand the colour of feathers displayed during that breeding season. If CORT levels at the end of breeding carry over to influence the immediately subsequent moult period as we expect, our results generally indicate that structural plumage quality may not be as sensitive to circulating CORT levels compared to carotenoid-based colouration. Future studies, particularly those employing experimental manipulations of CORT during moult in species with iridescent traits, are necessary to fully determine the role glucocorticoids play in mediating the quality of secondary sexual characteristics.

scholarly journals Evolutionary trade-offs between male secondary sexual traits revealed by a phylogeny of the hyperdiverse tribe Eumaeini (Lepidoptera: Lycaenidae)

2021 ◽  
Vol 288 (1950) ◽  
Author(s):  
Wendy A. Valencia-Montoya ◽  
Tiago B. Quental ◽  
João Filipe R. Tonini ◽  
Gerard Talavera ◽  
James D. Crall ◽  
...  
Keyword(s):  
Sexual Selection ◽  
Secondary Sexual Traits ◽  
Secondary Sexual Characteristics ◽  
Sexually Selected Traits ◽  
Trade Offs ◽  
Sexual Characteristics ◽  
Phylogenetic Framework ◽  
Sexual Traits ◽  
Selected Traits ◽  
Secondary Sexual

Male butterflies in the hyperdiverse tribe Eumaeini possess an unusually complex and diverse repertoire of secondary sexual characteristics involved in pheromone production and dissemination. Maintaining multiple sexually selected traits is likely to be metabolically costly, potentially resulting in trade-offs in the evolution of male signals. However, a phylogenetic framework to test hypotheses regarding the evolution and maintenance of male sexual traits in Eumaeini has been lacking. Here, we infer a comprehensive, time-calibrated phylogeny from 379 loci for 187 species representing 91% of the 87 described genera. Eumaeini is a monophyletic group that originated in the late Oligocene and underwent rapid radiation in the Neotropics. We examined specimens of 818 of the 1096 described species (75%) and found that secondary sexual traits are present in males of 91% of the surveyed species. Scent pads and scent patches on the wings and brush organs associated with the genitalia were probably present in the common ancestor of Eumaeini and are widespread throughout the tribe. Brush organs and scent pads are negatively correlated across the phylogeny, exhibiting a trade-off in which lineages with brush organs are unlikely to regain scent pads and vice versa . In contrast, scent patches seem to facilitate the evolution of scent pads, although they are readily lost once scent pads have evolved. Our results illustrate the complex interplay between natural and sexual selection in the origin and maintenance of multiple male secondary sexual characteristics and highlight the potential role of sexual selection spurring diversification in this lineage.

scholarly journals Adiposity, compared with masculinity, serves as a more valid cue to immunocompetence in human mate choice

2013 ◽  
Vol 280 (1751) ◽  
pp. 20122495 ◽  
Author(s):  
Markus J. Rantala ◽  
Vinet Coetzee ◽  
Fhionna R. Moore ◽  
Ilona Skrinda ◽  
Sanita Kecko ◽  
...  
Keyword(s):  
Mate Choice ◽  
Female Mate Choice ◽  
Good Genes ◽  
Secondary Sexual Traits ◽  
Genetic Quality ◽  
Secondary Sexual Trait ◽  
Sexual Traits ◽  
Handicap Hypothesis ◽  
The Relationship ◽  
Secondary Sexual

According to the ‘good genes’ hypothesis, females choose males based on traits that indicate the male's genetic quality in terms of disease resistance. The ‘immunocompetence handicap hypothesis’ proposed that secondary sexual traits serve as indicators of male genetic quality, because they indicate that males can contend with the immunosuppressive effects of testosterone. Masculinity is commonly assumed to serve as such a secondary sexual trait. Yet, women do not consistently prefer masculine looking men, nor is masculinity consistently related to health across studies. Here, we show that adiposity, but not masculinity, significantly mediates the relationship between a direct measure of immune response (hepatitis B antibody response) and attractiveness for both body and facial measurements. In addition, we show that circulating testosterone is more closely associated with adiposity than masculinity. These findings indicate that adiposity, compared with masculinity, serves as a more important cue to immunocompetence in female mate choice.

scholarly journals Baseline corticosterone does not reflect iridescent plumage traits in female tree swallows

2019 ◽  
Vol 270 ◽  
pp. 123-130 ◽  
Author(s):  
Keneth Sarpong ◽  
Christine L. Madliger ◽  
Christopher M. Harris ◽  
Oliver P. Love ◽  
Stéphanie M. Doucet ◽  
...  
Keyword(s):  
Tree Swallows ◽  
Female Tree ◽  
Baseline Corticosterone

scholarly journals Selective harvest focused on sexual signal traits can lead to extinction under directional environmental change

2017 ◽  
Vol 284 (1868) ◽  
pp. 20171788 ◽  
Author(s):  
Robert J. Knell ◽  
Carlos Martínez-Ruiz
Keyword(s):  
Environmental Change ◽  
Well Being ◽  
Secondary Sexual Traits ◽  
Secondary Sexual Trait ◽  
Trophy Hunting ◽  
Selective Harvest ◽  
Sexual Traits ◽  
The Relationship ◽  
Extreme Care ◽  
Secondary Sexual

Humans commonly harvest animals based on their expression of secondary sexual traits such as horns or antlers. This selective harvest is thought to have little effect on harvested populations because offtake rates are low and usually only the males are targeted. These arguments do not, however, take the relationship between secondary sexual trait expression and animal condition into account: there is increasing evidence that in many cases the degree of expression of such traits is correlated with an animal's overall well-being, which is partly determined by their genetic match to the environment. Using an individual-based model, we find that when there is directional environmental change, selective harvest of males with the largest secondary sexual traits can lead to extinction in otherwise resilient populations. When harvest is not selective, the males best suited to a new environment gain the majority of matings and beneficial alleles spread rapidly. When these best-adapted males are removed, however, their beneficial alleles are lost, leading to extinction. Given the current changes happening globally, these results suggest that trophy hunting and other cases of selective harvest (such as certain types of insect collection) should be managed with extreme care whenever populations are faced with changing conditions.

scholarly journals Factors affecting secondary sex characteristics in the yellowtail tetra Astyanax altiparanae

2019 ◽  
Author(s):  
Diógenes H. Siqueira-Silva ◽  
Rafaela M. Bertolini ◽  
Nycolas L. Pereira ◽  
Nivaldo F. Nascimento ◽  
José A. Senhorini ◽  
...  
Keyword(s):  
Gonadal Development ◽  
Medium Size ◽  
Sex Characteristics ◽  
Factors Affecting ◽  
Secondary Sexual Characteristics ◽  
Sexual Characteristics ◽  
Summary Statement ◽  
Mature Fish ◽  
Large Animals ◽  
Secondary Sexual

AbstractThis work aimed to analyze factors affecting secondary sexual characteristics in the yellowtail tetra Astyanax altiparanae. For this, seventy-five specimens were first separated into three different size classes (small, medium and large groups) between two seasons, summer and winter. In all groups, male fish were consistently bigger in the summer. On the other hand, females from both seasons presented in media the same length into the length classes. Afterwards, we performed histological analyses of the gonads to first confirm the genus and investigate the phase of maturation of each animal. During the winter, most of the small animals were males (22), most of the large animals, females (23), and the medium size animals followed a tendency of 1:1 ratio (9 male: 16 female). In the summer, male were the majority in both small (20) and medium (20) size. Larger-size animals were female (23). Then, in order to analyze the influence of genus, phase of maturation, season of the year, the number, and length of the animals spinelets, we diaphanized, counted, and measured them in each animal. Our results demonstrated that the spinelets are a sexual secondary characteristic of male genus independently of the size, season and phase of maturation. However, some tendencies were observed. Males bigger than 48 mm always presented spinelets; their size are in media the double in summer in comparison to winter; and summer males presents more rays with spinelets in the summer. Curiously, the larger specimen sampled was a female presenting spinelets in five rays. Lastly, we performed the gonadectomization of the animals and hypothesized that gonad hormones will directly influence this characteristic. The gonadectomization only initially influence on the size and number of spinelets in the anal fin rays, since the thirty-day-gonadectomized animals presented few and smaller spinelets against the control ones. However, the spinelets normalized in ninety-day-gonadectomized specimens. Such a work showed spinelets can be considered a secondary sexual characteristic to distinct male from female and can be used in the management in specimens bigger than 48 mm, but cannot indicate fish sterility.Summary statementThis study elucidated whether the size, sex, environmental conditions, and gonadal development affect the development of spinelets, a bony structure presented in anal fins in mature fish. Additionally, gonadectomized fish were used to elucidate the effect of gonad on the rise of such structures. Interesting new data showed that such a secondary sex characteristic is influenced by sex, size, gonadal development, and season of the year, but spinelets arose even within gonadectomized fish; this suggests that such a structure is not indicative of sterility in this species.

scholarly journals Reproductive effort affects subsequent horn growth in sexually dimorphic male ungulates

2021 ◽  
Author(s):  
Christian Simon Willisch ◽  
Peter Neuhaus
Keyword(s):  
Reproductive Effort ◽  
Evolutionary Ecology ◽  
Energy Allocation ◽  
Sexually Dimorphic ◽  
Capra Ibex ◽  
Secondary Sexual Characters ◽  
Horn Growth ◽  
Trade Offs ◽  
The Relationship ◽  
Secondary Sexual

AbstractTrade-offs between reproductive effort and subsequent growth in males are not well explored, despite their relevance in questions of individual energy allocation. Regarding the growth of sexual secondary characters in polygynous breeding male mammals, indeed, no conclusive studies exist. We investigated in male Alpine ibex (Capra ibex) the relationship between their behavioral reproductive effort, current horn size, and subsequent horn growth. While controlling for age, no evidence was found for male behavioral reproductive effort during the rut being affected by their horn size. On the other hand, reproductive effort significantly decreased age-specific horn growth during the following summer. Our study provides evidence that growth of secondary sexual characters is traded against behavioral investments in reproduction in a male mammal. It bears important implications for the understanding of energy allocation between various life-history components and the evolutionary ecology of secondary sexual characters.

Primary Amenorrhoea with Pituitary Dwarfism: A rare case report

2016 ◽  
Vol 2 (2) ◽  
pp. 145-147
Author(s):  
Siva S ◽  
Divya Gopineni ◽  
Shafi P ◽  
Chandra Sekhar
Keyword(s):  
Pituitary Gland ◽  
General Medicine ◽  
Pituitary Hormones ◽  
Thyroid Stimulating Hormone ◽  
Primary Amenorrhea ◽  
Pituitary Dwarfism ◽  
Primary Amenorrhoea ◽  
Sexual Characteristics ◽  
Loss Of Appetite ◽  
Secondary Sexual

Females with pituitary dwarfism and a multiple deficiency of pituitary hormones show ovarian dysfunction due to hypogonadotropism. Primary amenorrhea can be diagnosed if a patient has normal secondary sexual characteristics but no menarche by 16 years of age. A 16 year-old female patient admitted in general medicine department with chief complaints of shortness of breath on exertion since 15 days, swelling of both legs since 10 days, loss of weight since 5 months, loss of appetite since 3 months, history of pain during swallowing. Pelvis scan examination reveals that uterus measures 3.2×0.5×0.5cm; uterus is hypo plastic, ovaries not visualized. Patient parents reveled that from patient birth to 11years of age her growth and other developments were normal, after that her growth is stopped and no changes were observed in development since 5 years. Patient has hypothyroidism so pituitary gland make an important role to maintain hormone levels, pituitary gland produces thyroid stimulating hormone (TSH) which stimulates thyroid gland to produce thyroid hormones. Primary Amenorrhea, short stature and poorly developed secondary sexual characters which could have been contributed and should be subjected for karyotyping. This type of Pituitary Dwarfism is very difficult to manage.

The number of employed as a macroeconomic indicator of working time dynamics

2020 ◽  
Vol 16 (5) ◽  
pp. 935-945
Author(s):  
I.A. Zaikova
Keyword(s):  
Comparative Analysis ◽  
Manufacturing Sector ◽  
Working Hours ◽  
Working Time ◽  
Labor Costs ◽  
Factors Affecting ◽  
Time Dynamics ◽  
Developed Economies ◽  
The Relationship ◽  
Macroeconomic Indicator

Subject. The working time of workers at any stage of economic development is a value reflecting the level of labor productivity. Any progress in productivity contributes to changes in the volume of labor costs and the number of employed. Depending on the relationship between the total volume of labor costs and the number of employed, the duration of working time per one worker may change (it may increase, decrease, or remain unchanged). Objectives. The study aims to confirm the importance of such a macroeconomic indicator as the number of employed in varying working hours. Methods. The study rests on the comparative analysis of countries with developed economies based on some indicators like dynamics of the working time fund, dynamics of the number of employed, average number of hours worked during the year per employee, etc. The analyzed timespan is 25 years (from 1991 to 2016). Results. The comparative analysis revealed that in the non-production sphere and the economy as a whole the macroeconomic determinants correlate so that the length of working time per worker reduces. When considering the analysis results for the manufacturing sector, no single trend was identified. Conclusions. One of the key factors affecting the change in working hours is the number of employed. The relationship between the working time fund and the number of employed directly determines the dynamics of working time per worker.

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