Just like human beings, female orca whales live long after they give birth. In the case of other animals, however, the female dies soon after the childbearing period ends. According to anthropologists, grandmothers live longer to pass on the genes to the next generation. This is called “the grandmother effect”. A grandmother usually takes up the responsibility of feeding the children and taking care of them post her menopause.
You may think this is a trait that is exclusive to human beings. However, a recent study that was published in the journal, Proceedings of the National Academy of Sciences shows that orcas are similar too. Female orca whales/ killer whales stop giving birth after 45 years of age. But they live up to 80-90 years age and help their daughters nurture their children during this time.
The young whale’s chances of surviving are increased by the presence of the granny whales. These female killer whales live for a lengthy period of time after they stop bearing kids. The reason behind this is pretty simple. The grandmother whale has an in-depth knowledge of ecology and becomes a natural leader. She obtains food for her daughter’s calves according to Daniel Franks, the primary author of the study.
The study has taken into account groups of orca whales who live around the coast of British Columbia and Washington state. After studying census data of around forty years, they have come to the conclusion that the orca grandchildren do not live for long once their grandmother dies.
Chinook salmon is the favorite treat of Orcas and during the period of its unavailability, a lot of the grandchildren die. Female orcas stop bearing children when they are forty-five and live on for almost two more decades. While the daughter orca hunts, the grandmother nourishes the grandchildren.
The older the whale, the more likely it is to embrace the local group. Post the age when human females go through menopause, the orca whales are ready to pass on the genes by interacting with the children.
The bond between the female whales is a strong and fascinating one indeed.