Search results for "Sexual selectio"
showing 10 items of 255 documents
Height predicts jealousy differently for men and women
2008
Because male height is associated with attractiveness, dominance, and reproductive success, taller men may be less jealous. And because female height has a curvilinear relationship with health and reproductive success (with average-height females having the advantages), female height may have a curvilinear relationship with jealousy. In Study 1, male height was found to be negatively correlated with self-reported global jealousy, whereas female height was curvilinearly related to jealousy, with average-height women reporting the lowest levels of jealousy. In Study 2, male height was found to be negatively correlated with jealousy in response to socially influential, physically dominant, and…
Sexual cannibalism in Nephila plumipes as a consequence of female life history strategies
2002
The evolution of sexual cannibalism has been modelled as both an adaptive and nonadaptive female strategy. Recent evidence from several species suggests a connection between female foraging and sexual cannibalism, but the precise benefits for females have remained obscure. Here, we investigate the difference between cannibalistic and noncannibalistic female Nephila plumipes by removing the potential nutritional benefit of cannibalism. Courting and mating males that were killed by a female were immediately removed so that the female could not consume them. Nevertheless, cannibalistic females gained more mass from maturation to oviposition and produced larger first clutches than noncannibalis…
Assortative mating and female clutch investment in black grouse
1999
Variation in female behaviour has only recently received attention in studies of sexual selection. It has been suggested that females may invest differentially in their offspring in relation to the quality of their mate. This may lead to females that mate with high-quality and/or attractive males laying larger clutches. Females may also differ in their ability to choose between males. For example, females in good physical condition may make better choices. If physical condition and clutch size are positively correlated, this hypothesis could also produce a relationship between male attractiveness and female clutch size. We found, in lekking black grouse, Tetrao tetrix, that females mated to…
Variation in clutch size in relation to nest size in birds
2014
© 2014 The Authors. Nests are structures built to support and protect eggs and/or offspring from predators, parasites, and adverse weather conditions. Nests are mainly constructed prior to egg laying, meaning that parent birds must make decisions about nest site choice and nest building behavior before the start of egg-laying. Parent birds should be selected to choose nest sites and to build optimally sized nests, yet our current understanding of clutch size-nest size relationships is limited to small-scale studies performed over short time periods. Here, we quantified the relationship between clutch size and nest size, using an exhaustive database of 116 slope estimates based on 17,472 nes…
Coat darkness is associated with social dominance and mating behaviour in a mountain sheep hybrid lineage
2008
Natural hybridization can produce novel traits when morphologically different populations hybridize, and can introduce variation in traits that become associated with sexual selection. Evidence from breeding experiments and genetic markers indicate that the great variation in coat darkness and the unique coat patterns found in Stone's sheep Ovis dalli stonei, populations, have resulted from an ancient hybridization event between thinhorn sheep, O. dalli, and bighorn sheep, O. canadensis. Behavioural evidence gathered in 2003 and 2004 in Yukon Territory, Canada, showed that higher dominance rank was correlated with increasing darkness in rams, and comparatively darker rams were seen more oft…
Signalling and Reception
2002
Communication, a widespread natural phenomenon, occurs in both animals and plants. Signals are evolved traits that transfer information from one individual (the signaller) to another (the receiver); they can occur in any sensory modality. Keywords: cost and benefits; honesty; mimicry; predation; sexual selection
Mate choice for indirect genetic benefits: scrutiny of the current paradigm
2007
Summary 1Sexual selection through mate choice, and in particular female choice for indirect fitness benefits for their offspring, is a major paradigm that currently seems to enjoy almost unequivocal acceptance. A large body of theoretical work has been built to explain the evolution of mate choice in the absence of direct benefits, and the empiricists have enthusiastically verified the various assumptions and predictions of the theory. 2However, the relative importance of mate choice for indirect benefits in comparison to choice for direct benefits or to other mechanisms of sexual selection such as male–male competition or sensory exploitation remains a controversial issue, and this seems t…
Decreased sexual signalling reveals reduced viability in small populations of the drumming wolf spider Hygrolycosa rubrofasciata.
2004
One of the important goals in conservation biology is to determine reliable indicators of population viability. Sexual traits have been suggested to indicate population extinction risk, because they may be related to viability through condition dependence. Moreover, condition-dependent sexual traits may be more sensitive indicators of population viability than early life-history traits, because deleterious fitness effects of inbreeding tend to be expressed mainly at the end of the species' life history. However, empirical evidence of the significance of sexual behaviour for population viability is missing. In this study, we examined two male sexual traits and survival in 39 different-sized …
Testing the assumptions of conditional handicap theory: costs and condition dependence of a sexually selected trait
2000
Conditional handicap models of sexual selection predict that sexual traits are reliable signals of male quality because they are (a) condition dependent and (b) costly to produce or maintain. In this study, my objective was to experimentally investigate whether the drumming of male Hygrolycosa rubrofasciata wolf spiders is a condition-dependent costly trait. Males court females by drumming dry leaves with their abdomen and females preferentially mate with males drumming at higher rates. I manipulated male phenotypic condition and drumming rate simultaneously by keeping males on three different food rations and either introducing or not introducing them to a female. Food ration treatment aff…
Factors Affecting Male Song Evolution in Drosophila montana
2005
D. montana (a species of the D. virilis group) has spread over the northern hemisphere, populations from different areas showing both genetic and phenotypic divergence. The males of this species produce an elaborate courtship song, which plays a major role both in species recognition and in intraspecific mate choice. The genetic architecture and physical constraints, as well as the importance of the signal for species recognition, set boundaries within which this signal can vary. Within these limits, courtship song parameters may change, depending on the males' physical condition and on the environment they inhabit. Females are likely to affect song evolution by exerting directional selecti…