Eyespan reflects reproductive quality in wild stalk-eyed flies
Document Type
Article
Publication Date
1-1-2010
Abstract
Handicap models of sexual selection propose that females use male sexual ornaments as a cue in mate choice because they reflect commodities that increase female fitness, either directly or indirectly. In contrast to studies on vertebrates, most investigations of ornaments in insects and other invertebrate taxa have been conducted under laboratory conditions. There is a pressing need to address questions relating to sexual signalling of quality in natural populations, as the arbitrary and uniform environments found in the laboratory fail to reflect the world under which animals have evolved. We investigated associations between male ornaments (exaggerated eyespan), attractiveness, and reproductive quality in a wild population of the sexually ornamented stalk-eyed fly, Teleopsis dalmanni. We also explored the relationship between eyespan and reproductive quality in females to evaluate the potential for sexually antagonistic selection on eyespan. We show that eyespan is a generic correlate of reproductive quality, acting as a reliable mirror of variation in reproductive fitness in both sexes. Our findings suggest that male ornaments signal commodities that are of interest to females in the natural environment in which they, and mate preferences for them, have evolved. In addition, the covariance between female eyespan and reproductive output suggests that the former may be a reliable cue of quality in its own right. Our data provide important insights into the evolutionary forces that shape the evolution of exaggerated eyespan in wild populations of this species.
Keywords
Sexual selection, Ornaments, Wild, Stalk-eyed fly, Testis, Accessory glands, Fecundity, Fertility, Fly cyrtodiopsis-dalmanni, Sexual ornament size, Correlated responses, Condition dependence, Handicap principle, Mating frequency, Mate preferences, Trade-off, Selection, Diopsidae
Divisions
InstituteofBiologicalSciences
Publication Title
Evolutionary Ecology
Volume
24
Issue
1
Additional Information
Institute of Biological Sciences, Faculty of Science Building, University of Malaya, 50603 Kuala Lumpur, MALAYSIA