title: Social context-dependent modification of courtship behaviour in Drosophila prolongata.
abstract: Induction of alternative mating tactics by surrounding conditions, such as the presence of conspecific males, is observed in many animal species. Satellite behaviour is a remarkable example in which parasitic males exploit the reproductive investment by other males. Despite the abundance of parasitic mating tactics, however, few examples are known in which males alter courtship behaviour as a counter tactic against parasitic rivals. The fruit fly Drosophila prolongata shows prominent sexual dimorphism in the forelegs. When courting females, males of D. prolongata perform 'leg vibration', in which a male vibrates the female's body with his enlarged forelegs. In this study, we found that leg vibration increased female receptivity, but it also raised a risk of interception of the female by rival males. Consequently, in the presence of rivals, males of D. prolongata shifted their courtship behaviour from leg vibration to 'rubbing', which was less vulnerable to interference by rival males. These results demonstrated that the males of D. prolongata adjust their courtship behaviour to circumvent the social context-dependent risk of leg vibration.
authors.affiliation: Department of Agricultural and Environmental Biology, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Shiori
authors.initials: S
authors.lastname: Setoguchi
authors.affiliation: Department of Agricultural and Environmental Biology, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Kudo
authors.affiliation: Department of Forest Entomology, Forestry and Forest Products Research Institute, Matsuno-sato 1, Tsukuba, Ibaraki 305-8687, Japan.
authors.forename: Takuma
authors.initials: T
authors.lastname: Takanashi
authors.affiliation: Department of Agricultural and Environmental Biology, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Ishikawa
authors.affiliation: Department of Agricultural and Environmental Biology, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan matsuo@utlae.org.
authors.forename: Takashi
authors.initials: T
authors.lastname: Matsuo
mesh_terms: D000818:Animals; D003163:Competitive Behavior; D003380:Courtship; D004330:Drosophila / Q000502:physiology*; D005260:Female; D008297:Male; D012726:Sexual Behavior, Animal; D012931:Social Environment; D014732:Vibration
keywords: alternative mating tactics; courtship behaviour; sexual dimorphism; signal interception; social context