Determinants of Lek Mating Success in Male Galápagos Marine IguanasBehavior, Body Size, Condition, Ornamentation, Ectoparasite Load, and Female Choice

Author(s):  
William K. Hayes ◽  
Ronald L. Carter ◽  
Martin Wikelski ◽  
Jeffrey A. Sonnentag
2019 ◽  
Author(s):  
Guillermo E. Bachmann ◽  
Francisco Devescovi ◽  
Ana L. Nussenbaum ◽  
Fabián H. Milla ◽  
Todd E. Shelly ◽  
...  

AbstractExposure to plant compounds and analogues of juvenile hormone (JH) increase male mating success in several species of tephritid fruit flies. Most of these species exhibit a lek mating system, characterized by active female choice. Although the pattern of enhanced male mating success is evident, few studies have investigated what benefits, if any, females gain via choice of exposed males in the lek mating system. In the South American fruit fly,Anastrepha fraterculus, females mate preferentially with males that were exposed to volatiles released by guava fruit or treated with methoprene (a JH analogue). Here, we tested the hypothesis that female choice confers direct fitness benefits in terms of fecundity and fertility. We first carried out mate choice experiments presenting females with males treated and non-treated with guava volatiles or, alternatively, treated and non-treated with methoprene. After we confirm female preference for treated males, we compared the fecundity and fertility between females mated with treated males and non-treated ones. We found thatA. fraterculusfemales that mated with males exposed to guava volatiles showed higher fecundity than females mated to non-exposed males. On the other hand, females that mated methoprene-treated males showed no evidence of direct benefits. Our findings represent the first evidence of a direct benefit associated to female preference for males that were exposed to host fruit odors in tephritid fruit flies. Differences between the two treatments are discussed in evolutionary and pest management terms.


2017 ◽  
Author(s):  
Tobias Kordsmeyer ◽  
John Hunt ◽  
David Puts ◽  
Julia Ostner ◽  
Lars Penke

Recent evidence suggests that in sexual selection on human males, intrasexual competition plays a larger role than female choice. In a sample of men (N = 164), we sought to provide further evidence on the effects of men’s physical dominance and sexual attractiveness on mating success and hence in sexual selection. Objective measures and subjective ratings of male sexually dimorphic traits purportedly under sexual selection (height, vocal and facial masculinity, upper body size from3D scans, physical strength, and baseline testosterone) and observer perceptions of physical dominance and sexual attractiveness based on self-presentation video recordings were assessed and associated with mating success (sociosexual behaviour and number of potential conceptions) in a partly longitudinal design. Results from structural equation models and selection analyses revealed that physical dominance, but not sexual attractiveness, predicted mating success. Physical dominance mediated associations of upper body size, physical strength, as well as vocal and facial physical dominance and attractiveness with mating success. These findings thus suggest a greater importance of intrasexual competition than female choice in human male sexual selection.


1990 ◽  
Vol 40 (4) ◽  
pp. 648-652 ◽  
Author(s):  
R.M. Neems ◽  
A.J. McLachlan ◽  
R. Chambers
Keyword(s):  

2011 ◽  
Vol 279 (1734) ◽  
pp. 1784-1790 ◽  
Author(s):  
Suzanne H. Alonzo

Explaining the evolution of male care has proved difficult. Recent theory predicts that female promiscuity and sexual selection on males inherently disfavour male care. In sharp contrast to these expectations, male-only care is often found in species with high extra-pair paternity and striking variation in mating success, where current theory predicts female-only care. Using a model that examines the coevolution of male care, female care and female choice; I show that inter-sexual selection can drive the evolution of male care when females are able to bias mating or paternity towards parental males. Surprisingly, female choice for parental males allows male care to evolve despite low relatedness between the male and the offspring in his care. These results imply that predicting how sexual selection affects parental care evolution will require further understanding of why females, in many species, either do not prefer or cannot favour males that provide care.


2019 ◽  
Vol 97 (3) ◽  
pp. 220-224 ◽  
Author(s):  
H.V. Watkins ◽  
G. Blouin-Demers

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.


2007 ◽  
Vol 73 (6) ◽  
pp. 987-997 ◽  
Author(s):  
M.A. Serrano-Meneses ◽  
A. Córdoba-Aguilar ◽  
V. Méndez ◽  
S.J. Layen ◽  
T. Székely

Heredity ◽  
1989 ◽  
Vol 62 (1) ◽  
pp. 123-131 ◽  
Author(s):  
G Engelhard ◽  
S P Foster ◽  
T H Day

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