ABOVE: This is a photograph of the genital area of a female called 'Harmony', her head is to the lower right and her fluke to the left. Females have a lobe, known as the 'hemispherical lobe', at the lower end of the genital area which is shaped like half a grapefruit. They also have raised lips either side of the genital area from which the nipples protrude when a calf is feeding. By contrast the male genital area is flat and has no lobe. These features make it possible to determine the gender of a whale. Knowing whether a humpback is male or female is very important in interpreting and understanding behaviour.
(Photo: Trish Franklin)
|Nursing begins almost immediately. When the calf wishes to feed, the mothers nipples protrude the calf grasping the teat between its tongue and upper jaw. |
Because the calf must surface for air frequently, the initial nursing sessions last only a few seconds. Calves will nurse about forty times throughout the day and night and consume about three gallons of milk at each feeding.
A calf may depend upon its mother for over twelve months and weaning begins when they reach the feeding grounds in Antarctica.