Fig. 3From: Is sperm morphology functionally related to sperm swimming ability? A case study in a wild passerine bird with male hierarchiesRelation between the decay in sperm velocity (VCL) across time and sperm design across social ranks (a-d) after manipulating the social environment. The surfaces were obtained from predicted values extracted from linear mixed models. Larger PC values indicate larger flagella and mid-pieces relative to head size, and they are centered by social rankBack to article page