Sperm swimming speed and morphology differ slightly among the three genetic morphs of ruff sandpiper (Calidris pugnax), but show no clear polymorphism - Bulla, Martin; Küpper, Clemens; Lank, David B.; Albrechtová, Jana; Loveland, Jasmine L.; Martin, Katrin; Teltscher, Kim; Cragnolini, Margherita; Lierz, Michael; Albrecht, Tomáš; Forstmeier, Wolfgang; Kempenaers, Bart (Frontiers in Ecology and Evolution, 2024)