Operational sex ratio influences male-male competition in guppies (Poecilia reticulata)
1998
Mullica Jirotkul, Walailak Univ., Nakhon Si Thammarat (Thailand). Inst. of Science
Manipulation of operational sex ratio (OSR) in guppies (Poecilia reticulata) causes changes in male-male competition. OSR in this study is defined as the ratio of sexually active males divided by the total number of sexually active adults of both sexes. In this study, OSR was experimentally manipulated to determine its effect on male-male competition. At higher OSR, the rate of male courtship display decreased, and interference behaviors between males increased. OSR influenced both copulatory tactics and post-copulatory guarding. All copulations followed sigmoid displays, except at an OSR of 5:1 male:female where 60 percent of copulations occurred during sneak attempts. When compared to copulations that followed sigmoid displays, successful sneak copulations were followed by a shorter period of post-copulatory mate guarding and a shorter refractory period before males resumed courtship activities.
显示更多 [+] 显示较少 [-]