Search

A study of Gryllodes sigillatus to determine the relationship between investment in courtship food gifts and male fluctuating asymmetry (FA) revealed that there was no correlation between the level of FA and mass of the spermatophylax. While the female is consuming the spermatophylax, which she detaches from the male, the female reproductive tract receives the male's ampulla's contents. Larger spermatophylaxes give more time for the process of insemination and higher chances of fertilization success. However, production of overlarge spermatophylaxes may result in reduced frequency of mating.

Analysis of sequential mate choice reveals that the areas of individual information processing and tactical mate choice should be explored to help understand mate choice. Areas that need detailed analysis are how individuals detect best mates and their length of search. Individuals choose mates from a potential group by analyzing their qualities.

Guarding behavior in red-winged blackbirds, its benefits in preventing extrapair matings and the effect of food availability on foraging behavior and paternity are analyzed. Males guard their mates by companionship during fertilization and by chasing other males away from their mates. These behavioral patterns are expensive due to low male food intake, although it increases paternity by eliminating extrapair copulation.

A comparison of the mating of the Eurasian dotterel 'Charadrius Morinellus,' which exhibit female-female competition and male mate choice with sex-role-reversed-lekking, reveals that females are potentially polyandrous, and compete for males during mating. Both sexes exhibit intrasexual plumage variation, while females with comparatively and individually brighter plumage win most fights, court more and pair earlier with bright plumaged males. Absence of active mate choice by males reveals that females are more active in choosing mates.

The joint evolution of female mating preferences and male sexual display are described by most of the sexual selection models, but Fisher's model includes an analysis of their genetic correlation. Other models suggest several different mechanisms for the evolution of mating preferences though it is difficult to determine their relative importance and experimentally differentiate them. The pattern of variation in independently evolving populations that have different stages in the sexual selection process is examined experimentally. The data obtained provides information on the nature and evolutionary dynamics of the sexual selection processes.