scholarly journals Scent may signal fighting ability in male Iberian rock lizards

2007 ◽  
Vol 3 (2) ◽  
pp. 125-127 ◽  
Author(s):  
José Martín ◽  
Pilar López
Keyword(s):  
Sexual Selection ◽  
Body Size ◽  
Competitive Advantage ◽  
Intrasexual Competition ◽  
Chemical Signals ◽  
Lizard Species ◽  
Fighting Ability ◽  
Femoral Gland Secretions ◽  
Selection Of

Intrasexual competition favours the evolution of conspicuous fighting ability badges. However, in spite of the fact that chemoreception is important in sexual selection of many animals, such as lizards, the role of chemical signals in males' contests is relatively unknown. Here, we show that proportions of cholesterol in femoral gland secretions of male Iberian rock lizards were related to their body size (which confers a competitive advantage in fights). Males discriminated chemically and responded aggressively to cholesterol stimuli presented on swabs. Moreover, we experimentally increased cholesterol in the scent of males, and staged encounters in neutral cages between two unfamiliar and size-matched males. Focal males lost more agonisitic interactions against males manipulated with cholesterol than in control tests. We suggest that differences in scent composition may reliably signal fighting ability in many lizard species, which would help to avoid the costs of fighting.

Lipophilic Compounds from the Femoral Gland Secretions of Male Hungarian Green Lizards, Lacerta viridis

2009 ◽  
Vol 64 (5-6) ◽  
pp. 434-440 ◽  
Author(s):  
Renata Kopena ◽  
Pilar López ◽  
José Martín
Keyword(s):  
Mass Spectra ◽  
Chemical Compounds ◽  
Reproductive Behaviour ◽  
Sexual Signals ◽  
Lizard Species ◽  
Specific Chemical ◽  
Lipophilic Compounds ◽  
Lacerta Viridis ◽  
Femoral Gland Secretions

In spite of the importance of chemical signals (pheromones) in the reproductive behaviour of lizards, only a few studies have examined the role of specific chemical compounds as sexual signals. The secreted chemicals vary widely between species but whether this variation reflects phylogenetic or environmental differences remains unclear. Based on mass spectra, obtained by GC-MS, we found 40 lipophilic compounds in femoral gland secretions of male green lizards (Lacerta viridis), including several steroids, α-tocopherol, and esters of n-C16 to n-C20 carboxylic acids, and minor components such as alcohols between C12 and C20, squalene, three lactones and one ketone. We compared these chemicals with those previously found in other closely related green lizard species, and discussed how phylogenetical differences and/or environmental conditions could be responsible for the differential presence of chemicals in different lizard species.

scholarly journals The effect of fire on habitat selection of mammalian herbivores: the role of body size and vegetation characteristics

2014 ◽  
Vol 83 (5) ◽  
pp. 1196-1205 ◽  
Author(s):  
Stephanie L. Eby ◽  
T. Michael Anderson ◽  
Emilian P. Mayemba ◽  
Mark E. Ritchie
Keyword(s):  
Body Size ◽  
Habitat Selection ◽  
Mammalian Herbivores ◽  
Vegetation Characteristics ◽  
Selection Of

scholarly journals The Role of Sexual Selection in the Evolution of Chemical Signals in Insects

Insects ◽  
2014 ◽  
Vol 5 (2) ◽  
pp. 423-438 ◽  
Author(s):  
Sandra Steiger ◽  
Johannes Stökl
Keyword(s):  
Sexual Selection ◽  
Chemical Signals

scholarly journals It is not always about body size: evidence of Rensch's rule in a male weapon

2021 ◽  
Vol 17 (6) ◽  
pp. 20210234
Author(s):  
Glauco Machado ◽  
Bruno A. Buzatto ◽  
Diogo S. M. Samia
Keyword(s):  
Sexual Selection ◽  
Body Size ◽  
Potential Role ◽  
Empirical Studies ◽  
Condition Dependence ◽  
Rensch’S Rule ◽  
Evolutionary Pattern ◽  
Rensch's Rule ◽  
Original Proposal

In many species, sexual dimorphism increases with body size when males are the larger sex but decreases when females are the larger sex, a macro-evolutionary pattern known as Rensch's rule (RR). Although empirical studies usually focus exclusively on body size, Rensch's original proposal included sexual differences in other traits, such as ornaments and weapons. Here, we used a clade of harvestmen to investigate whether two traits follow RR: body size and length of the fourth pair of legs (legs IV), which are used as weapons in male–male fights. We found that males were slightly smaller than females and body size did not follow RR, whereas legs IV were much longer in males and followed RR. We propose that sexual selection might be stronger on legs IV length than on body size in males, and we discuss the potential role of condition dependence in the emergence of RR.

scholarly journals Antagonistic selection on body size and sword length in a wild population of the swordtail fish, Xiphophorus multilineatus: potential for intralocus tactical conflict

2021 ◽  
Author(s):  
Melissa Liotta ◽  
Jessica Abbott ◽  
Molly Morris ◽  
Oscar Rios-Cardenas
Keyword(s):  
Sexual Selection ◽  
Body Size ◽  
Wild Population ◽  
Genetic Correlations ◽  
Reproductive Tactics ◽  
Swordtail Fish ◽  
The Arts ◽  
In The Wild ◽  
Life History Tradeoffs

Alternative reproductive tactics (ARTs) have provided valuable insights into how sexual selection and life history tradeoffs can lead to variation within a sex. However, the possibility that tactics may constrain evolution through intralocus tactical conflict (IATC) is rarely considered. In addition, when IATC has been considered, the focus has often been on the genetic correlations between the ARTs, while evidence that the ARTs have different optima for associated traits and that at least one of the tactics is not at its optima is often missing. Here we investigate selection on three traits associated with the ARTs in the swordtail fish Xiphophorus multilineatus; body size, body shape and the sexually selected trait for which these fishes were named, sword length (elongation of the caudal fin). All three traits are tactically dimorphic, with courter males being larger, deeper bodied and having longer swords, and the sneaker males being smaller, more fusiform and having shorter swords. Using measures of reproductive success in a wild population we calculated selection differentials, linear and quadratic gradients, demonstrate that the tactics have different optima and at least one of the tactics is not at its optima for body size and sword length. Our results provide the first evidence of selection in the wild on the sword, an iconic trait for sexual selection. In addition, given the high probability that these traits are genetically correlated to some extent between the two tactics, our study suggests that IATC is constraining both body size and the sword from reaching their phenotypic optima. We discuss the importance of considering the role of IATC in the evolution of tactical dimorphism, how this conflict can be present despite tactical dimorphism, and how it is important to consider this conflict when explaining not only variation within a species but differences across species as well.

scholarly journals Ultraviolet signals fighting ability in a lizard

2006 ◽  
Vol 2 (2) ◽  
pp. 169-172 ◽  
Author(s):  
Jessica Stapley ◽  
Martin J Whiting
Keyword(s):  
Body Size ◽  
Mate Choice ◽  
Female Mate Choice ◽  
Fighting Ability ◽  
Initial Stage ◽  
Contest Outcome ◽  
Rival Assessment ◽  
Free Ranging ◽  
Male Contests

Ultraviolet (UV) signals are used in female mate choice in numerous taxa; however, the role of UV signals in male contests remains relatively unexplored. We experimentally reduced throat UV of free-ranging lizards ( Platysaurus broadleyi ) to test whether UV acts as a signal of fighting ability during male contests. We found that UV-reduced males were more likely to be challenged than control males. However, contest outcome was not influenced by UV-reduction, and this was despite other obvious asymmetries between opponents, such as body size and residency. Throat UV was confirmed as a signal of fighting ability because contests were more likely to escalate when one contestant had reduced UV. Therefore, throat UV, not body size or residency, was used during the initial stage of opponent assessment, but this did not influence contest outcome. The results suggest that UV overrides other traits that could function as signals during rival assessment.

scholarly journals Female Iberian wall lizards prefer male scents that signal a better cell-mediated immune response

2005 ◽  
Vol 1 (4) ◽  
pp. 404-406 ◽  
Author(s):  
Pilar López ◽  
José Martín
Keyword(s):  
Immune Response ◽  
Sexual Selection ◽  
Immune System ◽  
Mate Choice ◽  
Chemical Signals ◽  
Trade Off ◽  
Cell Mediated Immune Response ◽  
Podarcis Hispanica ◽  
Femoral Secretions ◽  
Selection Of

In spite of the importance of chemoreception in sexual selection of lizards, only a few studies have examined the composition of chemical signals, and it is unknown whether and how chemicals provide honest information. Chemical signals might be honest if there were a trade-off between sexual advertisement and the immune system. Here, we show that proportions of cholesta-5,7-dien-3-ol in femoral secretions of male Iberian wall lizards ( Podarcis hispanica ) were related to their T-cell-mediated immune response. Thus, only males with a good immune system may allocate higher amounts of this chemical to signalling. Furthermore, females selected scents of males with higher proportions of cholesta-5,7-dien-3-ol and lower proportions of cholesterol. Thus, females might base their mate choice on the males' quality as indicated by the composition of their chemical signals.

Social behavior and sexual dimorphism in the Bonaire whiptail, Cnemidophorus murinus (Squamata: Teiidae): the role of sexual selection

2003 ◽  
Vol 81 (11) ◽  
pp. 1781-1790 ◽  
Author(s):  
Troy A Baird ◽  
Laurie J Vitt ◽  
Teresa D Baird ◽  
William E Cooper, Jr. ◽  
Janalee P Caldwell ◽  
...  
Keyword(s):  
Sexual Selection ◽  
Body Size ◽  
Sexual Dimorphism ◽  
Male Aggression ◽  
Body Dimensions ◽  
Light Blue ◽  
Ultimate Causation ◽  
Courtship Activity ◽  
Coloration Patterns

We measured body dimensions and coloration and quantified the behavior of females and males of two color phases in the Bonaire whiptail, Cnemidophorus murinus, to begin addressing the ultimate causation for sexual dimorphism in this species. Examination of size-adjusted body dimensions revealed that males have wider, longer, and deeper heads as well as somewhat longer forelegs and hind legs. Males were characterized by two distinct coloration patterns. Blue males displayed purple–blue dewlaps, blue–gray background coloration on the head and anterior torso, numerous light blue spots on the flanks, brown–orange coloration on the posterior torso, and a turquoise section on the proximal portion of the tail. By contrast, brown males were uniform olive–green to yellow–brown, with the exception of light blue spots on the lateral torso. Females were colored like brown males but lacked the blue spots. Testis length scaled with body size. Testes of only 26% of brown males were active, whereas all blue males had active testes. Blue males initiated aggressive encounters involving chases and displays directed toward other males much more frequently than females were aggressive with consexuals or with either type of male. Brown males were not observed to initiate aggression. Most blue male aggression was directed toward other blue males (70.6% of encounters), whereas 29.4% of encounters were with brown males. Blue males initiated 85.7% of the courtship encounters observed compared with only 7.1% initiated by brown males and 7.2% by females. Male-biased dimorphism in head and leg dimensions as well as coloration, together with higher rates of intrasexual aggression and courtship activity by blue males, are consistent with the hypothesis that sexual selection explains the evolution of sexual dimorphism in C. murinus.

scholarly journals MEMAHAMI PERAN EKUITAS MEREK SEBAGAI KEUNGGULAN BERSAING TERHADAP PENGAMBILAN KEPUTUSAN DALAM PEMILIHAN PERGURUAN TINGGI

2017 ◽  
Vol 21 (3) ◽  
pp. 398
Author(s):  
Yuli Harwani
Keyword(s):  
Decision Making ◽  
Competitive Advantage ◽  
Brand Equity ◽  
Structural Equation ◽  
Equation Model ◽  
Analysis Tool ◽  
Pls Analysis ◽  
Descriptive Method ◽  
Selection Of

This study aims to understand the role of brand equity as a competitive advantage associated with the decision-making process in the selection of universities. The research method used in this research is descriptive method. The object of this research as many as 100 people in West Jakarta, especially in the area of Kembangan and Kebon Jeruk. The approach used in this research is Structural Equation Model (SEM) with Smart PLS analysis tool. The results showed that brand equity has a positive and significant impact on competitive advantage. Brand equity has a positive and significant impact on decision stability. However, competitive advantage shows no effect on decision making.

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