According to one study, the ratio of males to females averaged 1 to 23. The males display visually and vocally from the water while the females rest. A display occurs both at and below the surface and lasts about two to three minutes. When displaying males are present, subadult males are scarce or absent. Those present remain on the fringes of the group and do not display.
Females leave the ice to join a male in the water, where copulation takes place.
After the mating season, mature bulls return to all-male herds. All Rights Reserved.