Sex Differences in Body Size and Ectoparasite Load in the Ball Python, Python regius

2005 ◽  
Vol 39 (2) ◽  
pp. 315-320 ◽  
Author(s):  
Fabien Aubret ◽  
Xavier Bonnet ◽  
Mathews Harris ◽  
Stéphanie Maumelat
Keyword(s):  
Sex Differences ◽  
Body Size ◽  
Python Regius ◽  
Ectoparasite Load

Body size, not age, predicts parasite load in Clark’s Spiny Lizards (Sceloporus clarkii)

2019 ◽  
Vol 97 (3) ◽  
pp. 220-224 ◽  
Author(s):  
H.V. Watkins ◽  
G. Blouin-Demers
Keyword(s):  
Body Size ◽  
Surface Area ◽  
Intraspecific Variation ◽  
Wild Population ◽  
Parasite Load ◽  
Older Individuals ◽  
Fundamental Goal ◽  
Males And Females ◽  
Ectoparasite Load

Determining the factors that influence parasite load is a fundamental goal of parasitology. Body size often influences parasite load in reptiles, but it is unclear whether higher levels of parasitism are a result of greater surface area of individuals (a function of size) or of longer periods of exposure to parasites (a function of age). Using skeletochronology in a wild population of Clark’s Spiny Lizards (Sceloporus clarkii Baird and Girard, 1852), we tested the hypotheses that (i) larger individuals have higher parasite loads due to increased surface area available for colonization by parasites and their vectors and that (ii) older individuals have higher parasite loads because they have had longer exposure to parasites and their vectors. Males harboured more ectoparasites than females. Males and females differed in how body size influenced chigger (Acari: Trombiculidae) load; larger males harboured more chiggers than smaller males, but this was not the case in females. Age did not affect ectoparasite load in either sex. These results emphasize the importance of disentangling the effects of size and age in models of parasitism to gain a clearer understanding of intraspecific variation in parasite load.

Factors driving sexual dimorphism and colour variability in the Achala Copper Lizard (Pristidactylus achalensis), an endemic species to the highland mountains in central Argentina

2020 ◽  
Vol 98 (6) ◽  
pp. 377-389
Author(s):  
S. Naretto ◽  
M. Chiaraviglio
Keyword(s):  
Sex Differences ◽  
Spatial Distribution ◽  
Body Size ◽  
Sexual Dimorphism ◽  
Endemic Species ◽  
Morphological Changes ◽  
Head Size ◽  
Head Width ◽  
Temporal And Spatial Distribution ◽  
Central Argentina

The intensity of mating competition varies according to the temporal and spatial distribution of individuals. Measuring sexual dimorphism over time and interpreting the association between individuals is therefore important if we aim to understand how sexual traits are influenced. We examined sex differences in the Achala Copper Lizard (Pristidactylus achalensis (Gallardo, 1964)), an endemic species from the highest part of mountains of central Argentina. Over 4 years, we explored sex-specific variation in body size, head size, interlimb length, and body colouration. Furthermore, we evaluated how these traits varied temporally, and we also explored whether the spatial distribution of individuals is explained by variation in these traits. We found that P. achalensis is a species with sexual dimorphism in multiple characters, including body size, head size, and colouration. Interestingly, some traits related to mating, such as head width, show a temporal variability in both sexes, whereas other traits, such as colouration, varies seasonally only in males. Our results underline the intriguing possibility of seasonal morphological changes related to mating, and more broadly that sex differences are influenced by sexual selection pressures mediated by temporal variation in mate competition.

scholarly journals Increased mortality in women: sex differences in burn outcomes

2017 ◽  
Vol 5 ◽  
Author(s):  
Karen Karimi ◽  
Iris Faraklas ◽  
Giavonni Lewis ◽  
Daniel Ha ◽  
Bridget Walker ◽  
...  
Keyword(s):  
Sex Differences ◽  
Body Size ◽  
Surface Area ◽  
Body Surface Area ◽  
Body Surface ◽  
Thermal Injury ◽  
Inhalation Injury ◽  
Inpatient Mortality ◽  
Burn Centers ◽  
Significant Difference

Abstract Background There is increasing evidence that sex differences may influence responses after thermal injury and affect clinical outcomes. The objective of this study was to evaluate the relationships between sex, thermal injury, body size, and inpatient mortality in burn patients. Methods Medical records of adults with >20% total body surface area (TBSA) burn injury admitted to two American Burn Association (ABA)-verified burn centers between 2008 and 2014 were retrospectively reviewed. Injury details and baseline characteristics, including body size as estimated by body surface area (BSA) and body mass index (BMI) were recorded, along with details of the hospital course. The primary outcome of inpatient mortality was compared between sexes. Results Out of 334 subjects, 60 were women (18%). Median TBSA was 33% (IQR 25–49) in this cohort, with 19% full thickness burns and 30% inhalation injury. Despite no significant difference in age, presence of inhalation injury, TBSA, or depth of burn, women had significantly higher rates of inpatient mortality (45 vs. 29%, P = 0.01). BSA was significantly lower in women vs. men (P < 0.001), but this difference was not more pronounced among non-survivors. There was no difference in BMI between men and women non-survivors. Although not significant (P = 0.28), women succumbed to their injuries sooner than men (day 4 vs. 10 post-injury). Conclusions Women are less likely to survive burn injuries and die sooner than men with similar injuries. Body size does not appear to modulate this effect. Burn centers should be aware of the higher mortality risk in women with large burns.

Interspecific variation in sexual dimorphism in brain size in Nearctic ground squirrels (Spermophilus spp.)

2001 ◽  
Vol 79 (5) ◽  
pp. 759-765 ◽  
Author(s):  
Andrew N Iwaniuk
Keyword(s):  
Sex Differences ◽  
Body Size ◽  
Sexual Dimorphism ◽  
Ground Squirrel ◽  
Mating Systems ◽  
Resource Competition ◽  
Brain Size ◽  
Ground Squirrels ◽  
Detailed Knowledge ◽  
Size Dimorphism

A possible relationship between sexual dimorphism in brain size and mating system was investigated in five ground squirrel species: Spermophilus lateralis, S. tridecemlineatus, S. richardsonii, S. columbianus, and S. parryii. Relative brain size was measured by determining the endocranial volume of 247 ground squirrel skulls and regressing these values against two measurements of body size: mass and length. Analyses of covariation in the brain size / body size relationship within the five species revealed that sexual brain-size dimorphism occurs in three of the five species: S. lateralis, S. richardsonii, and S. tridecemlineatus. Application of a reduced major axis regression model indicated, however, that only S. lateralis and S. richardsonii exhibit significant sexual brain-size dimorphism. These findings suggest that the degree of sexual brain-size dimorphism is not directly correlated with variation in mating systems. Spatial abilities may play a role in the evolution of sexual brain-size dimorphism in ground squirrels, but the spatial requirements of mating systems appear to be insufficient. The possibility of sex differences in cognition, resource competition, and other variables as contributory factors to the evolution of sexual brain-size dimorphism is offered, but detailed knowledge of sex differences in the behaviour of ground squirrels is required to provide a definitive answer.

RACE AND SEX DIFFERENCES IN THE EFFECT OF BODY SIZE ON BLOOD PRESSURE IN ADOLESCENCE?

2001 ◽  
Vol 33 (5) ◽  
pp. S156
Author(s):  
H H. Maes ◽  
M C. Neale ◽  
L J. Eaves ◽  
R M. Schieken
Keyword(s):  
Blood Pressure ◽  
Sex Differences ◽  
Body Size

Sex differences in body size and body condition in breeding Temminck’s Stints Calidris temminckii

2008 ◽  
Vol 150 (1) ◽  
pp. 299-302 ◽  
Author(s):  
Terje Lislevand ◽  
Gunnhild Marthinsen ◽  
Jan T. Lifjeld
Keyword(s):  
Sex Differences ◽  
Body Size ◽  
Body Condition

Sex Differences in Verbal and Spatial Ability Reconsidered in Relation to Body Size Lung Volume, and Sex Hormones

2003 ◽  
Vol 96 (3_suppl) ◽  
pp. 1347-1360 ◽  
Author(s):  
Üner Tan ◽  
Mukadder Okuyan ◽  
Tugba Albayrak ◽  
Ahmet Akgun
Keyword(s):  
Sex Differences ◽  
Body Size ◽  
Mental Rotation ◽  
Sex Difference ◽  
Sex Hormones ◽  
Lung Volume ◽  
Verbal Ability ◽  
Mental Rotation Task ◽  
Intelligence Test ◽  
Better Than

Sex differences in verbal and nonverbal abilities were reconsidered in relation to bodily measures and sex hormones in Turkish university students. Perceptual-verbal ability was evaluated using As Test. To assess the nonverbal abilities, the mental rotation test and Cattell's Culture Fair Intelligence Test were used. As expected, the 53 women performed better than men on the As Test; 79 men had a higher mean than the 53 women on the mental rotation task; there was no sex difference on Cattell's IQ Test. Cattell IQs correlated only with tidal volume of lungs. Scores on the As Test did not show significant correlations with body size and lung capacities. Mental rotation was significantly correlated with height, weight, and lung volume. With covariates of height, weight, and vital capacity, sex differences in mental rotation completely disappeared, but the difference on the As Test increased while Cattell IQ remained sex-neutral. With testosterone as covariate, the sex difference on the As test increased but on the mental rotation task disappeared; Cattell IQ was sex-neutral. With covariates of estradiol and progesterone, sex differences on the As test disappeared; mental rotation scores and Cattell IQ were not influenced. Under a combined covariation of height, weight, and testosterone, sex differences in mental rotation reversed, women scoring better than men; after adding estradiol or progesterone instead of testosterone to this model, sex differences on mental rotation completely disappeared, but verbal ability and Cattell IQ were not changed. These results suggest that Cattell's Culture Fair Intelligence Test is unique in resistance to sex differences; perceptual-verbal ability was the most sex-specific mental trait but with dependence on estradiol; mental rotation, on the contrary, was least sex-specific, depending on body size, lung volume, sex hormones, and their combined actions, which explains women's better performance.

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