In a study, which was recently published in the scientific journal Current Biology, it turned out that mothers make a lifelong sacrifice for their sons.
The daughters, on the other hand, become independent quickly and are significantly easier to raise, according to the study, reports Science Radio.
When the researchers followed killer whale families in the North Pacific for 40 years, they discovered that the sons are extremely dependent on their mothers for a long time and that the mothers are forced to expend so much energy to provide food for their young that it endangers their own health.
When orca daughters become independent, the sons remain dependent on their mothers for a long time and even require the mother to share her own food with them.
The chance of reproducing again as a mother of an orca son is also significantly lower compared to if the mother raises a daughter.