Immler, SimonePryke, SarahBirkhead, Tim RGriffith, Simon C.2015-12-130014-3820http://hdl.handle.net/1885/79324Sperm morphometry (i.e., size and shape) and function are important determinants of male reproductive success and are thought to be under stabilizing selection. However, recent studies suggest that sperm morphometry can be a phenotypically plastic trait,Keywords: corticosterone; testosterone; aggression; behavioral ecology; environmental effect; hormone; life history trait; morphometry; natural selection; passerine; phenotypic plasticity; reproductive success; sperm; sperm competition; steroid; animal; article; bl Corticosteroid hormones; Phenotypic plasticity; Social hierarchy; Sperm competition; Sperm morphometry201010.1111/j.1558-5646.2009.00924.x2016-02-24