Male body size varies with latitude in a temperate lizard

2007 ◽  
Vol 85 (5) ◽  
pp. 626-633 ◽  
Author(s):  
Briar J. Howes ◽  
Stephen C. Lougheed
Keyword(s):  
Body Size ◽  
Sexual Size Dimorphism ◽  
Integrated Approach ◽  
Interspecific Variation ◽  
Species Group ◽  
Male Body ◽  
Latitudinal Cline ◽  
Male Body Size ◽  
Female Body Size ◽  
Plestiodon Fasciatus

To examine the evolution of sexual size dimorphism (SSD), interspecific studies are often performed to generate hypotheses for the origin and maintenance of SSD. Although these methods are invaluable to our understanding of the evolution of SSD, they often quantify SSD for a species based on few populations. We found a significant sex-specific latitudinal cline in Plestiodon fasciatus (L., 1758) (=  Eumeces fasciatus (L., 1758)), a species that was previously considered to be monomorphic for body size. Male body size significantly increased with increasing latitude, whereas female body size was relatively constant. Our findings argue for the importance of increased understanding and appreciation of intraspecific variation in SSD. We suggest that a more integrated approach to SSD be employed, where both intraspecific and interspecific variation is considered. We provide a foundation for posing hypotheses of the causes and consequences of SSD in P. fasciatus and perhaps other members of the species group.

Sexual size dimorphism in the American rubyspot: male body size predicts male competition and mating success

2007 ◽  
Vol 73 (6) ◽  
pp. 987-997 ◽  
Author(s):  
M.A. Serrano-Meneses ◽  
A. Córdoba-Aguilar ◽  
V. Méndez ◽  
S.J. Layen ◽  
T. Székely
Keyword(s):  
Body Size ◽  
Mating Success ◽  
Sexual Size Dimorphism ◽  
Male Competition ◽  
Male Body ◽  
Size Dimorphism ◽  
Male Body Size

Geographic variation in body size and sexual size dimorphism of North American Ratsnakes (Pantherophis spp. s.l.)

2018 ◽  
Vol 96 (11) ◽  
pp. 1196-1202 ◽  
Author(s):  
Brett A. DeGregorio ◽  
Gabriel Blouin-Demers ◽  
Gerardo L.F. Carfagno ◽  
J. Whitfield Gibbons ◽  
Stephen J. Mullin ◽  
...  
Keyword(s):  
Body Size ◽  
Large Scale ◽  
Sexual Size Dimorphism ◽  
Size Variation ◽  
Sexually Dimorphic ◽  
Male Body ◽  
Complex Species ◽  
Size Dimorphism ◽  
Body Size Variation ◽  
Female Body Size

Because body size affects nearly all facets of an organism’s life history, ecologists have long been interested in large-scale patterns of body-size variation, as well as why those large-scale patterns often differ between sexes. We explored body-size variation across the range of the sexually dimorphic Ratsnake complex (species of the genus Pantherophis Fitzinger, 1843 s.l.; formerly Elaphe obsoleta (Say in James, 1823)) in North America. We specifically explored whether variation in body size followed latitudinal patterns or varied with climatic variables. We found that body size did not conform to a climatic or latitudinal gradient, but instead, some of the populations with the largest snakes occurred near the core of the geographic range and some with the smallest occurred near the northern, western, and southern peripheries of the range. Males averaged 14% larger than females, although the degree of sexual size dimorphism varied between populations (range: 2%–25%). There was a weak trend for male body size to change in relation to temperature, whereas female body size did not. Our results indicate that relationships between climate and an ectotherm’s body size are more complicated than linear latitudinal clines and likely differ for males and females.

scholarly journals Sneaker Males Affect Fighter Male Body Size and Sexual Size Dimorphism in Salmon

2016 ◽  
Vol 188 (2) ◽  
pp. 264-271 ◽  
Author(s):  
Laura K. Weir ◽  
Holly K. Kindsvater ◽  
Kyle A. Young ◽  
John D. Reynolds
Keyword(s):  
Body Size ◽  
Sexual Size Dimorphism ◽  
Male Body ◽  
Size Dimorphism ◽  
Male Body Size

Effects of body size and mass on running speed of male yellow-pine chipmunks (Tamias amoenus)

2002 ◽  
Vol 80 (9) ◽  
pp. 1584-1587 ◽  
Author(s):  
Albrecht I Schulte-Hostedde ◽  
John S Millar
Keyword(s):  
Body Size ◽  
Mating Success ◽  
Sexual Size Dimorphism ◽  
Small Male ◽  
Male Body ◽  
Running Speed ◽  
Size Dimorphism ◽  
Male Body Size ◽  
Tamias Amoenus ◽  
Yellow Pine

Male-biased sexual size dimorphism in mammals is usually attributed to the success of large males in intrasexual combat for mates. However, mating success may be determined by contests that are not combative. In the mating chase of the yellow-pine chipmunk (Tamias amoenus), a mammalian species with female-biased sexual size dimorphism, fast males may have an advantage in acquiring matings with estrous females. However, the effects of intraspecific variation in body size on running speed are not obvious; heavy individuals may run more slowly than light individuals because excess mass can be a hindrance to locomotion, but individuals that are structurally large may run faster than small individuals because of longer stride length. We examined the effects of both body mass and structural size on running speed in male yellow-pine chipmunks using manipulated runs in which male chipmunks were chased over a known distance. Structurally large male chipmunks had faster running speeds than small males, potentially giving large males an advantage when chasing estrous females. However, small male chipmunks are known to be aggressively dominant over large males. This leads to a potential trade-off in male body size between two behavioural components of mating success (running speed and dominance) that may constrain the evolution of male body size, ultimately leading to female-biased sexual size dimorphism.

scholarly journals Male body size and male‐male competition: Interspecific variation in poeciliid fishes

1996 ◽  
Vol 63 (4) ◽  
pp. 365-369 ◽  
Author(s):  
Angelo Bisazza ◽  
Nicola Novarini ◽  
Andrea Pilastro
Keyword(s):  
Body Size ◽  
Interspecific Variation ◽  
Male Competition ◽  
Male Body ◽  
Male Body Size

scholarly journals A uni- and multivariate analysis approach to reveal sexual size dimorphism in Iranian populations of Hypera postica (Coleoptera: Curculionidae)

Biologia ◽  
2015 ◽  
Vol 70 (9) ◽  
pp. 1228-1233 ◽  
Author(s):  
Ehsan Sanaei ◽  
Marjan Seiedy ◽  
Farzaneh Momtazi
Keyword(s):  
Body Size ◽  
Sexual Size Dimorphism ◽  
Egg Laying ◽  
Morphological Divergence ◽  
High Fecundity ◽  
Hypera Postica ◽  
Size Dimorphism ◽  
Female Body Size ◽  
Divergence Pattern ◽  
Iranian Populations

Abstract Body size dimorphism between genders is a commonly observed phenomenon in insects, usually manifested in larger female body size. Sexual Size Dimorphism (SSD) varies from species to species, the degree and direction influenced by certain evolutionary pressures. Intraspecific variation in SSD may also occur between populations. The Hypera postica (Gyllenhal, 1813) is a well-known alfalfa plant pest that shows a degree of morphological divergence in its populations. The female alfalfa weevils are very fecund and have a larger body size compared to males. To improve our knowledge on magnitude and direction of SSD in alfalfa weevil, we studied 200 specimens of H. postica from four Iranian populations (Karaj1, Karaj2, Tuyserkan and Jovein). 10 morphological variables from three external anatomic parts (pronotum, elytra and rostrum) and 45 ratio characters were statistically analyzed in order to determine the amount of SSD in Iranian populations. In addition we investigated for morphological divergence pattern in mentioned populations. The results of this study show that a low degree of morphological divergence occurs in Iranian populations. Measured variables indicate that the SSD pattern of H. postica is compatible with the Rensch’s rule, and is related to high fecundity of females and a lack of strong sexual selection. Also it is mentioned that the larger rostrum in females may correspond to its unique role in egg laying.

Intra- and intersexual selection on male body size in the annual killifish Austrolebias charrua

2013 ◽  
Vol 96 ◽  
pp. 20-26 ◽  
Author(s):  
Carlos Passos ◽  
Bettina Tassino ◽  
Marcelo Loureiro ◽  
Gil G. Rosenthal
Keyword(s):  
Body Size ◽  
Male Body ◽  
Male Body Size ◽  
Annual Killifish

scholarly journals A new species of Kurixalus from western Yunnan, China (Anura, Rhacophoridae)

ZooKeys ◽  
2018 ◽  
Vol 770 ◽  
pp. 211-226 ◽  
Author(s):  
Guohua Yu ◽  
Hong Hui ◽  
Dingqi Rao ◽  
Junxing Yang
Keyword(s):  
New Species ◽  
Body Size ◽  
Outer Edge ◽  
Male Body ◽  
Male Body Size ◽  
Western Yunnan ◽  
A New Species

A new species of the genus Kurixalus (Anura: Rhacophoridae) is described from western Yunnan, China. Genetically the new species, Kurixalusyangi sp. n., is closer to Kurixalusnaso than to other known congeners. Morphologically the new species is distinguished from all other known congeners by a combination of the following characters: smaller ratios of head, snout, limbs, IND, and UEW to body size; male body size larger than 30 mm; curved canthus rostralis; weak nuptial pad; brown dorsal color; absence of large dark spots on surface of upper-middle abdomen; presence of vomerine teeth; gold brown iris; single internal vocal sac; serrated dermal fringes along outer edge of limbs; granular throat and chest; rudimentary web between fingers; and presence of supernumerary tubercles and outer metacarpal tubercle.

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