Whales

Whales Life Cycle

Sexual maturity occurs anywhere between the ages of six and thirteen years, depending on the species and whether the whale feeds through a baleen plate or is toothed. Toothed whales tend to live longer and take longer to wean from the nutrient-rich milk of their mothers. Small toothed whales can live for up to 30 years, while their larger counterparts’ lives are extended to about 70 years of age. Baleen whales have been known to live up to about 80. Incredibly, there have been reports of whales living for much longer, but this is rare.

When whales reach sexual maturity, they travel in pods to their breeding grounds. These pods can either be small family pods in which a female and her male escort stick together and mate (the calf will stay within this small pod until its adolescence) or a matriarchal pod, which consists of a larger group of female whales led by a matriarchal cow. Baleen whales tend to follow the family pod structure and toothed whales prefer the matriarchal arrangement. Once in the warmer waters of their breeding grounds, whales will mate. If the female does not have a previous mate with which she wants to mate, the bulls will woo her with their haunting songs and displays of strength. She has the final decision regarding which bull she selects.

They will start their relationship by going through courtship, much the same way as humans date prospective partners. As they bond, they will stroke one another with their dorsal fins as a gesture of affection. It is vital that she chooses a strong, healthy bull so that her calf stands a greater chance of survival. When she is satisfied that the bull meets her criteria, they will mate. This is done belly-to-belly beneath the water. Gestation lasts for between nine and sixteen months. The female will return to the breeding grounds to give birth so that the calf is born in more temperate waters.

The calf is about a quarter of the length of its mother at birth. As soon as it is born (tail first), it is imperative that the calf rises to the surface for its first breath of fresh air. Members of the matriarchal pods are known to assist the calf to the water's surface, despite the fact that whale calves are able to swim from birth. The mother's milk is extremely rich in nutrients and has a very high fat content. This allows the baby to grow very rapidly within the first few days, weeks and months of its life. This helps it to form the layer of fat, called blubber, beneath the surface of its skin. This will keep it warm in the icy waters as it provides insulation to these warm-blooded mammals. It also acts as an energy reserve to keep the calf strong and healthy during its migrations.

The age of weaning depends entirely on the species. Baleen whale calves are weaned by their first summer (less than a year old), while a toothed whale may take two to three years to be completely independent of its mother's milk. If the female calf has been raised in a matriarchal pod, she is likely to stay with that pod for her entire life. Bull calves will slowly break away from the core pod and form bachelor pods, comprising several bulls of the same age. These bachelors will travel the waters looking for female mates, but will have nothing to do with her or her calf after copulation.

By adhering to a strict life cycle, whales strengthen existing family bonds as each member fulfils specific roles depending on its life stage.

The life cycle of a whale is a fascinating study. Would you like to know more? Use the left navigation bar to find out more about the whale life cycle.