The development of sexual dimorphism: seasonal and lifetime mass changes in bighorn sheep

1996 ◽  
Vol 74 (2) ◽  
pp. 330-342 ◽  
Author(s):  
Marco Festa-Bianchet ◽  
Wendy J. King ◽  
Jon T. Jorgenson ◽  
Kirby G. Smith ◽  
William D. Wishart
Keyword(s):  
Sexual Dimorphism ◽  
Mass Loss ◽  
Mass Gain ◽  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
Age Classes ◽  
Male And Female ◽  
Absolute Mass ◽  
June July ◽  
Mass Accumulation

Individually marked bighorn sheep (Ovis canadensis) were monitored to determine how seasonal and lifetime changes in mass affected the development of sexual dimorphism, and to what extent mass at a given age could predict mass of the same sheep at a later age. We trapped sheep from late May to early October each year from 1971 to 1985 in a population artificially kept at low density. Lambs and yearlings gained mass linearly from June to September, while absolute mass gain of older sheep was faster in June–July than in August–September. Males gained more mass than females each summer up to at least 3 years of age. Relative summer mass gain, calculated as a proportion of body mass at the beginning of June, was the same for male and female lambs but was greater for male than for female yearlings and 2-year-olds. With the exception of lambs, all age-classes lost mass during winter. Mass loss between September 15 and June 5 was greater for females than for males, possibly because ewes lost mass through parturition in late May. For both sexes, asymptotic mass was not reached until at least 7 years of age. Mass at 4 and 12 months of age was correlated with mass at 4 years. For all sex–age classes, mass on June 5 was negatively correlated with summer mass gain. For lambs and yearlings, winter mass loss was positively correlated with mass on September 15. Our results suggest that at low population density, sheep optimize rather than maximize summer mass accumulation. Most sexual dimorphism develops after weaning, through faster mass gain by males than by females at 1 and 2 years of age and possibly a longer season of mass gain each year for males than for females after females reach puberty.

Body mass and survival of bighorn sheep

1997 ◽  
Vol 75 (9) ◽  
pp. 1372-1379 ◽  
Author(s):  
Marco Festa-Bianchet ◽  
Jon T. Jorgenson ◽  
Céline H. Bérubé ◽  
Christine Portier ◽  
William D. Wishart
Keyword(s):  
Body Mass ◽  
Adult Life ◽  
Mass Gain ◽  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
Adult Males ◽  
Age Classes ◽  
River Population ◽  
Maternal Expenditure ◽  
Chest Girth

In ungulates, body mass is often positively correlated with juvenile survival, but little is known of whether body mass affects survival of other age-classes. We studied two marked populations of bighorn sheep (Ovis canadensis) in Alberta, Canada, to determine if body mass affected the survival of different sex –age classes. Chest girth at weaning was correlated (P < 0.0001) with survival of bighorn lambs in the Sheep River population. In the Ram Mountain population, body mass in mid-September had a stronger effect upon survival than mass in early June, mass gain in summer, or mass loss in winter. Body mass at weaning was correlated with lamb survival (P = 0.004). In both study areas, relationships between size and survival of lambs were similar for the two sexes. At Ram Mountain, survival of yearling and adult males seemed to be independent of body mass. Light yearling females were less likely to survive than heavy yearling females. Among females aged 3 – 6 years, body mass had no effect on survival. Among females 7 years of age and older, mass in mid-September had a weak but significant (P = 0.03) effect on survival. Females were slightly lighter in mid-September in their last year of life than in the rest of their adult life. Maternal expenditure is unlikely to affect the survival of prime-age ewes, but may have a detrimental effect on the survival of older ewes.

Roads, routes and rams: does sexual segregation contribute to anthropogenic risk in a desert-dwelling ungulate?

2016 ◽  
Vol 43 (5) ◽  
pp. 380 ◽  
Author(s):  
Vernon C. Bleich ◽  
Jericho C. Whiting ◽  
John G. Kie ◽  
R. Terry Bowyer
Keyword(s):  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
Sexual Segregation ◽  
Adult Males ◽  
Large Mammals ◽  
Male And Female ◽  
Use Of Resources ◽  
Core Areas ◽  
Males And Females ◽  
Time Of Year

Context Little is known about the consequences of sexual segregation (differential use of resources by the sexes outside of the mating season) for the conservation of large mammals. Roadways (i.e. the strip of land over which a road or route passes) are ubiquitous around the world, and are a major cause of wildlife mortality, as well as habitat loss and fragmentation. Many populations of bighorn sheep (Ovis canadensis) occur at low densities and in a metapopulation structure. Roadways could affect movements of males and females differentially, an outcome that has not been considered previously. Aims We investigated the propensity of the sexes to cross a paved two-lane road and a single-lane, maintained dirt route and predicted that adult males, because of their life-history characteristics, would cross those roadways more often than females. Methods We investigated movements of male and female bighorn sheep from 1986 to 1990. We used a fixed-wing aircraft with an H-antenna on each wing strut to locate individuals each week from October 1986 to December 1990. We estimated the degree of overlap among 50% core areas of use by males and females with the utilisation distribution overlap index (UDOI). Key results We relocated male and female bighorn sheep on 948 occasions during sexual aggregation and on 1951 occasions during sexual segregation. More males than females were likely to cross both types of roadways during segregation, and the dirt route during aggregation. Propensity of males and females to cross roadways was strongly influenced by time of year (i.e. whether the period of sexual aggregation or sexual segregation). The lowest overlap in 50% core areas was between females and males during periods of segregation (UDOI = 0.1447). Conclusions More males than females crossed Kelbaker Road and the unnamed dirt route during segregation, as well as the unnamed route during aggregation. Both of those features could affect males more than females, and could result in reductions in the use of habitat or increased mortality of bighorn sheep from vehicle collisions as a result of spatial segregation of the sexes. Implications During environmental review, biologists should consider sexual segregation when assessing potential anthropogenic effects on movements of bighorn sheep. Biologists also should consider sexual segregation and how roadways, even lightly traveled routes, affect movements of male and female ungulates differently before manipulating habitat, translocating animals, or constructing or modifying roadways.

Sexual size dimorphism in bighorn sheep (Ovis canadensis): effects of population density

2001 ◽  
Vol 79 (9) ◽  
pp. 1661-1670 ◽  
Author(s):  
Mylène LeBlanc ◽  
Marco Festa-Bianchet ◽  
Jon T Jorgenson
Keyword(s):  
Population Density ◽  
Body Mass ◽  
Phenotypic Expression ◽  
Mass Gain ◽  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
The Body ◽  
Young Males ◽  
Negative Effect ◽  
Female Body Mass

Sexual dimorphism is an important characteristic of many mammals, but little is known about how environmental variables may affect its phenotypic expression. The relationships between population size, body mass, seasonal mass changes, and sexual mass dimorphism were investigated using 22 years of data on individually marked bighorn sheep (Ovis canadensis) on Ram Mountain, Alberta. The number of adult ewes was artificially maintained low from 1972 to 1981 and then allowed to increase. The body mass of males from 0 to 7 years of age was negatively affected by population density. Female body mass was negatively affected by population density up to 2 years of age. As the number of ewes increased, sexual mass dimorphism of sheep aged 2–7 years declined. Population density had a negative effect on seasonal mass changes of young males and females. Density also had a weak but significant positive effect on yearly mass gain of 2-year-old females, suggesting compensatory growth. Females appear to compensate for resource shortages early in life, while males show a lifelong negative effect. We suggest that these sexual differences are due to the greater flexibility of resource allocation to growth or reproduction by females than by males.

Mass change in Antarctic fur seal (Arctocephalus gazella) pups in relation to maternal characteristics at the Kerguèlen Islands

2000 ◽  
Vol 78 (3) ◽  
pp. 476-483 ◽  
Author(s):  
Christophe Guinet ◽  
Mary-Anne Lea ◽  
Simon D Goldsworthy
Keyword(s):  
Growth Rate ◽  
Mass Loss ◽  
Mass Gain ◽  
Trip Duration ◽  
Specific Rate ◽  
Arctocephalus Gazella ◽  
Kerguelen Islands ◽  
Absolute Mass ◽  
The Mean ◽  
Maternal Allocation

Maternal allocation to growth of the pup was measured in Antarctic fur seals (Arctocephalus gazella) at the Kerguèlen Islands during the 1997 austral summer. Absolute mass gain of pups following a maternal foraging trip was independent of the sex of the pup but was positively related to foraging-trip duration and maternal length. However, daily mass gain (i.e., absolute mass gain of the pup divided by foraging-trip duration) decreased with increasing foraging-trip duration but increased with maternal length. While the pup were fasting, their daily mass loss was related to their sex and initial body mass: both heavier pups and female pups lost more mass per day than lighter pups and male pups. The mass-specific rate of mass loss was significantly higher in female than in male pups. Over the study period, the mean growth rate was zero, with no difference between female and male pups. The growth rate in mass of the pup was positively related to maternal length but not to maternal condition, and negatively related to the foraging-trip duration of the mother and the initial mass of the pup. This indicates that during the study period, heavier pups grew more slowly because of their higher rate of daily mass loss during periods of fasting. Interestingly, for a given maternal length, the mean mass of the pup during the study period was higher for male than for female pups, even though the rate of daily mass gain was the same. Such differences are likely to result from sex differences in the mass-specific rate of mass loss. As female pups lose a greater proportion of their mass per day, a zero growth rate (i.e., mass gain only compensating for mass loss) is reached at a lower mass in female pups than in male pups. Our results indicate that maternal allocation does not differ according to the sex of the pup, but suggest that the two sexes follow different growth strategies.

Comparative assessment of average clinical smile parameters in male and female patients with orthognathic occlusion

2020 ◽  
Vol 25 (2) ◽  
pp. 121-126
Author(s):  
V. G. Galonsky ◽  
N. V. Tarasova ◽  
V. V. Aliamovskii ◽  
I. S. Leonovich
Keyword(s):  
Sexual Dimorphism ◽  
Male And Female ◽  
Young Males ◽  
Young Females ◽  
Female Patients ◽  
Evaluation Of Parameters ◽  
Distinguishing Features ◽  
Vertical Size ◽  
Relative Concept ◽  
The Ideal

Relevance. Separate issues in anthropomorphic sizes of relative norm of the ideal smile, its qualitative and qualitative parameters have not been addressed to sufficiently and are not properly reflected in scientific literature.Purpose. To determine distinguishing features in average smile parameters of the smile in male and female patients with orthognathic occlusion.Materials and methods. A clinical and anthropometric evaluation of parameters in main smile types was carried out for 150 young males and 150 young females aged 19-24 who had identical physiological development parameters.Results. It has been revealed that occurrence frequency of main smile types in patients with orthognathic occlusion has pronounced signs of sexual dimorphism which in over one half of the cases lies in predominance of the incisal smile type in males (52.7%) and the fascial type in females (55.3%). Occurence frequency of the cervical smile type totaled 25% among the studied patients of both genders. Average vertical size parameters in the incisal smile lies within the diapason of 3.91-4.91mm with surpassing by 1mm in males. Analogical data for the fascial smile type form the diapason of 6.21-6.73mm with surpassing by 0.52mm in females. The cervical smile type is characterised by larger vertical size forming the diapason of 7.94-8.91mm with surpassing by 0.97mm in males.Conclusion. The results of the study have shown that the “beautiful and ideal smile” is a relative concept having varied anthropometric characteristics and pronounced signs of sexual dimorphism lying in a broad spectrum of the dentofacial system norm notion with specific vectors for individual morphological deviations.

scholarly journals Sex-dependent dynamics of metabolism in primary mouse hepatocytes

2021 ◽  
Author(s):  
Luise Hochmuth ◽  
Christiane Körner ◽  
Fritzi Ott ◽  
Daniela Volke ◽  
Kaja Blagotinšek Cokan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Amino Acid ◽  
Sexual Dimorphism ◽  
New Drugs ◽  
Model Systems ◽  
Specific Gene ◽  
Primary Hepatocytes ◽  
Alcoholic Fatty Liver ◽  
Male And Female ◽  
Primary Mouse

AbstractThe liver is one of the most sexually dimorphic organs. The hepatic metabolic pathways that are subject to sexual dimorphism include xenobiotic, amino acid and lipid metabolism. Non-alcoholic fatty liver disease and hepatocellular carcinoma are among diseases with sex-dependent prevalence, progression and outcome. Although male and female livers differ in their abilities to metabolize foreign compounds, including drugs, sex-dependent treatment and pharmacological dynamics are rarely applied in all relevant cases. Therefore, it is important to consider hepatic sexual dimorphism when developing new treatment strategies and to understand the underlying mechanisms in model systems. We isolated primary hepatocytes from male and female C57BL6/N mice and examined the sex-dependent transcriptome, proteome and extracellular metabolome parameters in the course of culturing them for 96 h. The sex-specific gene expression of the general xenobiotic pathway altered and the female-specific expression of Cyp2b13 and Cyp2b9 was significantly reduced during culture. Sex-dependent differences of several signaling pathways increased, including genes related to serotonin and melatonin degradation. Furthermore, the ratios of male and female gene expression were inversed for other pathways, such as amino acid degradation, beta-oxidation, androgen signaling and hepatic steatosis. Because the primary hepatocytes were cultivated without the influence of known regulators of sexual dimorphism, these results suggest currently unknown modulatory mechanisms of sexual dimorphism in vitro. The large sex-dependent differences in the regulation and dynamics of drug metabolism observed during cultivation can have an immense influence on the evaluation of pharmacodynamic processes when conducting initial preclinical trials to investigate potential new drugs.

scholarly journals Brucellosis in Captive Rocky Mountain Bighorn Sheep (Ovis canadensis) Caused by Brucella abortus Biovar 4

2004 ◽  
Vol 40 (2) ◽  
pp. 311-315 ◽  
Author(s):  
Terry J. Kreeger ◽  
Walter E. Cook ◽  
William H. Edwards ◽  
Todd Cornish
Keyword(s):  
Brucella Abortus ◽  
Rocky Mountain ◽  
Bighorn Sheep ◽  
Ovis Canadensis

scholarly journals Balanced conditions or slight mass gain of glaciers in the Lahaul and Spiti region (northern India, Himalaya) during the nineties preceded recent mass loss

2013 ◽  
Vol 7 (2) ◽  
pp. 569-582 ◽  
Author(s):  
C. Vincent ◽  
Al. Ramanathan ◽  
P. Wagnon ◽  
D. P. Dobhal ◽  
A. Linda ◽  
...  
Keyword(s):  
Mass Loss ◽  
Field Measurements ◽  
Mass Gain ◽  
Negative Mass ◽  
Northern India ◽  
Chhota Shigri Glacier ◽  
Digital Elevation ◽  
Recent Compilation ◽  
Spiti Region ◽  
Dem Differencing

Abstract. The volume change of the Chhota Shigri Glacier (India, 32° 20 N, 77° 30' E) between 1988 and 2010 has been determined using in situ geodetic measurements. This glacier has experienced only a slight mass loss between 1988 and 2010 (−3.8 ± 2.0 m w.e. (water equivalent) corresponding to −0.17 ± 0.09 m w.e. yr−1). Using satellite digital elevation models (DEM) differencing and field measurements, we measure a negative mass balance (MB) between 1999 and 2010 (−4.8 ± 1.8 m w.e. corresponding to −0.44 ± 0.16 m w.e. yr−1). Thus, we deduce a slightly positive or near-zero MB between 1988 and 1999 (+1.0 ± 2.7 m w.e. corresponding to +0.09 ± 0.24 m w.e. yr−1). Furthermore, satellite DEM differencing reveals that the MB of the Chhota Shigri Glacier (−0.39 ± 0.15 m w.e. yr−1) has been only slightly less negative than the MB of a 2110 km2 glaciarized area in the Lahaul and Spiti region (−0.44 ± 0.09 m w.e. yr−1) during 1999−2011. Hence, we conclude that the ice wastage is probably moderate in this region over the last 22 yr, with near equilibrium conditions during the nineties, and an ice mass loss after. The turning point from balanced to negative mass budget is not known but lies probably in the late nineties and at the latest in 1999. This positive or near-zero MB for Chhota Shigri Glacier (and probably for the surrounding glaciers of the Lahaul and Spiti region) during at least part of the 1990s contrasts with a recent compilation of MB data in the Himalayan range that indicated ice wastage since 1975. However, in agreement with this compilation, we confirm more negative balances since the beginning of the 21st century.

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