scholarly journals Sexual selection in cane toads Rhinella marina: A male’s body size affects his success and his tactics

2013 ◽  
Vol 59 (6) ◽  
pp. 747-753 ◽  
Author(s):  
Haley Bowcock ◽  
Gregory P. Brown ◽  
Richard Shine
Keyword(s):  
Body Size ◽  
Mate Choice ◽  
Mating Systems ◽  
Male Body ◽  
Size Discrimination ◽  
Physical Strength ◽  
Dry Tropics ◽  
Body Sizes ◽  
And Behavior ◽  
Size Preference

Abstract Male body size can play an important role in the mating systems of anuran amphibians. We conducted laboratory-based trials with cane toads Rhinella (Bufo) marina from an invasive population in the wet-dry tropics of northern Australia, to clarify the effects of a male’s body size on his reproductive success and behavior (mate choice). Males were stimulated with a synthetic hormone to induce reproductive readiness. Larger body size enhanced a male toad’s ability to displace a smaller rival from amplexus, apparently because of physical strength: more force was required to dislodge a larger than a smaller amplectant male. A male’s body size also affected his mate-choice criteria. Males of all body sizes were as likely to attempt amplexus with another male as with a female of the same size, and preferred larger rather than smaller sexual targets. However, this size preference was stronger in larger males and hence, amplexus was size-assortative. This pattern broke down when males were given access to already-amplectant male-female pairs: males of all body sizes readily attempted amplexus with the pair, with no size discrimination. An amplectant pair provides a larger visual stimulus, and prolonged amplexus provides a strong cue for sex identification (one of the individuals involved is almost certainly a female). Thus, a male cane toad’s body size affects both his ability to defeat rivals in physical struggles over females, and the criteria he uses when selecting potential mates, but the impacts of that selectivity depend upon the context in which mating occurs.

scholarly journals Mate Choice and Copulation Frequency in the Burying BeetleNicrophorus quadripunctatus(Coleoptera: Silphidae): Effect of Male Body Size and Presence of a Rival

2009 ◽  
Vol 2009 ◽  
pp. 1-4 ◽  
Author(s):  
Seizi Suzuki
Keyword(s):  
Body Size ◽  
Mate Choice ◽  
Significant Interaction ◽  
Copulation Duration ◽  
Male Body ◽  
Male Size ◽  
High Quality ◽  
Male Body Size ◽  
Rival Male

It is widely assumed that there exists a competition between males for mating and that females prefer males with elaborate male traits. Further, such traits are considered to be synonymous with high quality in terms of benefits to females. The number and duration of copulations and the frequency of mate refusal between large and smallNicrophorus quadripunctatusmales were examined both for single males and for two males competing. The number of copulations was not affected by the size of the male or by the presence of a rival, but there was a significant interaction such that large males increased their number of copulations when a small rival was present. Copulation duration was not affected by male size but was shortened by a rival male. Females rejected copulation attempts of small males more often than of large males, whether the males were alone or paired with a rival. These results suggest that large males have two advantages: they win contests between males and are preferred by females.

Mating system, mate choice and parental care in a bark beetle

2017 ◽  
Vol 107 (5) ◽  
pp. 611-619 ◽  
Author(s):  
O. Baruch ◽  
Z. Mendel ◽  
I. Scharf ◽  
A. R Harari
Keyword(s):  
Body Size ◽  
Reproductive Success ◽  
Mate Choice ◽  
Parental Care ◽  
Mating System ◽  
Assortative Mating ◽  
Bark Beetle ◽  
Biparental Care ◽  
Male Body ◽  
Male Body Size

AbstractThe cypress bark beetle,Phloeosinus armatus, is a common element of the dying cypress tree system in East-Mediterranean countries. Adult beetles congregate for breeding on this ephemeral resource. We studied three traits that characterize this beetle's sexual behavior and linked them to its reproductive success: mating system, mate choice, and parental care. We found that the females are the ‘pioneering sex’, excavating the mating chamber. The average female is slightly larger than the male, and female and male body size is correlated, demonstrating size-assortative mating. The time it takes for a male to enter the mating chamber is positively correlated with female size and negatively correlated with its own size, which is perhaps responsible for this assortative mating. Males remain in the gallery during the period of oviposition, gradually leaving soon after the eggs hatch. The number of eggs laid and tunnel length are positively correlated with male body size. Finally, in the presence of both parents, more eggs are laid than when the female alone is present, demonstrating the important contribution of biparental care for reproductive success. We suggest that the interaction between a monogamous mating system, assortative mating, and biparental care contributes to reproductive success.

Does recent experience affect large male advantage in a sequentially-mating fish?

Behaviour ◽  
2021 ◽  
pp. 1-29
Author(s):  
Emily R. Allen ◽  
Laura K. Weir
Keyword(s):  
Body Size ◽  
Mating Success ◽  
Mating Systems ◽  
Interactive Effect ◽  
Large Male ◽  
Recent Experience ◽  
Small Male ◽  
Male Body ◽  
Mating Experience ◽  
Male Advantage

Abstract In many mating systems, large male body size is associated with dominance in direct contests with rivals and females may exhibit preference for larger males. As such, body size is often positively associated with mating success. However, mating experience can influence the potential advantage of large body size through alterations in behaviour and depletion of sperm reserves. In Japanese medaka (Oryzias latipes), males mate with many females each day, and larger males mate more frequently than smaller males. In an observational experiment, we tested the following alternate predictions: (1) recent mating experience may enhance mating success through a carry-over effect of prior mating, whereby small experienced males gain an advantage over large inexperienced rivals in mating contests; or (2) recent mating experience decreases mating success through a reduction in fertilization due to sperm limitation, effectively dampening the large-male advantage against a small inexperienced rival. We examined the interactive effect of size and recent experience on mating behaviour and success. While mating contests were monopolized by large males, recent experience enhanced mating success, especially in small male winners. Experienced males courted more readily than those without recent experience, suggesting that recent prior mating enhances this behaviour. Furthermore, males who had copulated recently did not exhibit sperm depletion when in the presence of a competitor, nor did female behaviour indicate a preference for inexperienced males. This suggests that males can use sexual experience to increase their reproductive success in future mating situations, which may influence the action of sexual selection and alternative tactics in shaping mating systems.

Mate choice and mate competition influence male body size in Japanese medaka

1998 ◽  
Vol 55 (5) ◽  
pp. 1151-1163 ◽  
Author(s):  
R.D. HOWARD ◽  
R.S. MARTENS ◽  
S.A. INNIS ◽  
J.M. DRNEVICH ◽  
J. HALE
Keyword(s):  
Body Size ◽  
Mate Choice ◽  
Japanese Medaka ◽  
Mate Competition ◽  
Male Body ◽  
Male Body Size

Mate choice in field crickets: can females acoustically detect male body size?

2009 ◽  
Vol 28 (1) ◽  
pp. 141-151 ◽  
Author(s):  
L. Verburgt ◽  
J. W. H. Ferguson
Keyword(s):  
Body Size ◽  
Mate Choice ◽  
Male Body ◽  
Male Body Size ◽  
Field Crickets

scholarly journals Does divergence in female mate choice affect male size distributions in two cave fish populations?

2008 ◽  
Vol 4 (5) ◽  
pp. 452-454 ◽  
Author(s):  
Michael Tobler ◽  
Ingo Schlupp ◽  
Martin Plath
Keyword(s):  
Sexual Selection ◽  
Body Size ◽  
Mate Choice ◽  
Female Choice ◽  
Female Mate Choice ◽  
Female Preference ◽  
Large Male ◽  
Male Body ◽  
Male Size ◽  
Female Mate

Sexual selection by female choice can maintain male traits that are counter selected by natural selection. Alteration of the potential for sexual selection can thus lead to shifts in the expression of male traits. We investigated female mate choice for large male body size in a fish ( Poecilia mexicana ) that, besides surface streams, also inhabits two caves. All four populations investigated, exhibited an ancestral visual preference for large males. However, only one of the cave populations also expressed this female preference in darkness. Hence, the lack of expression of female preference in darkness in the other cave population leads to relaxation of sexual selection for large male body size. While P. mexicana populations with size-specific female mate choice are characterized by a pronounced male size variation, the absence of female choice in one cave coincides with the absence of large bodied males in that population. Our results suggest that population differences in the potential for sexual selection may affect male trait variation.

Male antler flies (Protopiophila litigata; Diptera: Piophilidae) are more selective than females in mate choice

1998 ◽  
Vol 76 (7) ◽  
pp. 1277-1285 ◽  
Author(s):  
Russell Bonduriansky ◽  
Ronald J Brooks
Keyword(s):  
Body Size ◽  
Mate Choice ◽  
Mate Guarding ◽  
Egg Load ◽  
Male Body ◽  
Effective Protection ◽  
Mating Costs ◽  
Female Quality ◽  
Dipteran Species ◽  
Better Than

We investigated mate choice in the antler fly (Protopiophila litigata Bonduriansky), which forms mating aggregations and oviposits exclusively on discarded cervid antlers, by pairing males with nongravid females and by collecting copulating pairs on antlers. Because females probably receive larger ejaculates (which they partly ingest after mating) and more effective protection (mate guarding) from large males than from small ones, we expected females to prefer large males as mates. Because males experience high mating costs and often encounter females lacking mature eggs, we expected males to reject some females. Moreover, because relative abdomen width (fatness) predicts the number of mature eggs (egg load) of a female better than her body size does, we expected males to evaluate female quality by assessing female fatness. Of the 54 male-female pairings, 7 (13%) resulted in copulation, the female rejected the male in 6 (11%), and the male rejected the female in 41 (76%). We found no significant differences between individuals that mated and those that did not. However, females disproportionately rejected males smaller than themselves. Males exhibited a preference (quantified as duration of abdominal tapping bouts) for fat females as mates. Small males appeared to be less choosy than large males. Because males rejected potential mates more frequently than females (apparently) did, males may have been choosier than females. Coupled pairs collected on antlers exhibited positive assortment by body size and positive correlation of male body size with female egg load. These mate-choice and mating-assortment patterns may occur in many dipteran species, where copulation is costly for both sexes, females often lack mature eggs, and mating is initiated in dense aggregations of aggressive males.

Observations on activity, display behavior, coloration and androgen levels in the keeled earless lizard, Holbrookia propinqua

1991 ◽  
Vol 12 (1) ◽  
pp. 57-66 ◽  
Author(s):  
William E. Cooper ◽  
Louis J. Guillette
Keyword(s):  
Body Size ◽  
Small Sample Size ◽  
Small Sample ◽  
Male Body ◽  
Observation Distance ◽  
Large Size ◽  
Color Morphs ◽  
Body Sizes ◽  
Selection For ◽  
The Relationship

AbstractWe observed the distance moved, number of movements, and frequency of displays in ten minute intervals for two male color morphs, coral and yellow, and for brightly colored females, of Holbrookia propinqua. We also measured body sizes and, for males, plasma androgen concentrations. Distance moved, number of movements, and number of social displays were positively correlated in males. Females exhibited similar correlations, but the relationship between distance moved and number of displays was not significant. Males moved more often and greater distances than females. Females performed displays as frequently as did males, perhaps because we selected large, dominant females for observation. Distance moved, number of movements, and number of displays increased with body size in males. That these relationships did not hold in females may indicate a sex difference or reflect the small sample size and body size range of females. Plasma androgen concentrations increased with male body size, suggesting a possible androgenic mechanism of sexual selection for large size. Androgen level did not affect display frequency or distance moved. Distance moved increased with plasma androgen concentration, but when effects of body size were held constant, this relationship vanished. Coral and yellow males did not differ in androgen concentration, size, or in the observed behaviors.

Body Dissatisfaction: The Ideal Body and a Summary of Theories of Development and Maintenance

2020 ◽  
Author(s):  
Daniel Talbot
Keyword(s):  
Body Size ◽  
Body Dissatisfaction ◽  
Muscle Tone ◽  
Subjective Evaluation ◽  
Male Body ◽  
Ideal Body ◽  
Physiological Outcomes ◽  
The Ideal

Body dissatisfaction can be defined as a negative subjective evaluation of one’s body as a whole, or relating to specific aspects of one’s body such as body size, shape, muscularity/muscle tone, and weight. Prior research has found that body dissatisfaction is associated with a number of negative psychological and physiological outcomes. This commentary describes the Western ideal male body, as well as providing a summary of theories of the cause and maintenance of male body dissatisfaction.

scholarly journals A Farewell to the Encephalization Quotient: A New Brain Size Measure for Comparative Primate Cognition

2021 ◽  
pp. 1-12
Author(s):  
Carel P. van Schaik ◽  
Zegni Triki ◽  
Redouan Bshary ◽  
Sandra A. Heldstab
Keyword(s):  
Body Size ◽  
Cognitive Abilities ◽  
Brain Size ◽  
Estimation Error ◽  
Primate Species ◽  
Mammal Species ◽  
Mean Values ◽  
Encephalization Quotient ◽  
Body Sizes ◽  
Size Measure

Both absolute and relative brain sizes vary greatly among and within the major vertebrate lineages. Scientists have long debated how larger brains in primates and hominins translate into greater cognitive performance, and in particular how to control for the relationship between the noncognitive functions of the brain and body size. One solution to this problem is to establish the slope of cognitive equivalence, i.e., the line connecting organisms with an identical bauplan but different body sizes. The original approach to estimate this slope through intraspecific regressions was abandoned after it became clear that it generated slopes that were too low by an unknown margin due to estimation error. Here, we revisit this method. We control for the error problem by focusing on highly dimorphic primate species with large sample sizes and fitting a line through the mean values for adult females and males. We obtain the best estimate for the slope of circa 0.27, a value much lower than those constructed using all mammal species and close to the value expected based on the genetic correlation between brain size and body size. We also find that the estimate of cognitive brain size based on cognitive equivalence fits empirical cognitive studies better than the encephalization quotient, which should therefore be avoided in future studies on primates and presumably mammals and birds in general. The use of residuals from the line of cognitive equivalence may change conclusions concerning the cognitive abilities of extant and extinct primate species, including hominins.

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