Menopausal Orca Whales become Pod Leaders
Orca whales can be spotted on many Arctic and Antarctic expedition cruises because they live in every ocean on the planet. Adventurers and scientists have been observing these creatures, which are often referred to by their more colorful nickname of killer whales, for many years. However, new evidence has just been confirmed that helps showcase the hierarchy of their pods. Unlike many animal species that demote elderly members over time into serving more of a background or caregiver role, orca whales appear to embrace the wisdom that comes with age. In fact, research that took 35 years of data into account has conclusively proven that post-menopausal females serve a vital function as pod leaders.
Why is This Unusual?
The main survival pattern of every species on earth relies upon constant reproduction, but menopause removes this ability from women. This is believed to be the primary reason that females in most species do not live for very long after they reach this stage of their life. Humans have evolved to the point where women can live for several decades after they lose their ability to reproduce, but this is a very rare trait as there are less than a handful of other species that have been observed doing the same thing. However, even humans do not typically elevate elderly individuals into a leadership role over an entire family structure. Instead, they branch out into their own smaller structures that are usually led by people of child-bearing age.
© Laurens Steijn | Oceanwide Expeditions
What Function Do These Orca Whales Serve?
Female orca whales usually enter menopause around the age of 50, and this is consistent with the typical human experience. Orcas also have an average life expectancy of 90 years, and most human women will live long enough to celebrate their 86th birthday. These similarities make it clear that orcas and people have a lot in common from a lifespan and reproductive standpoint, but killer whales seem to take the concept of having respect for the elderly in a much bolder direction.
Female orcas that are no longer able to reproduce are often found at the head of their pod. These whales also appear to be responsible for directing the entire pod, and they have an impact on the group’s feeding habits. For example, researchers discovered that the elderly female at the head of the pod takes a greater level of control when it becomes harder to find enough food to feed everyone properly. When the hunt for food is on, younger male orcas will flank closely behind the leader in order to take advantage of her specialized hunting and survival knowledge. These males were usually birthed by the leader, and they tend to stick by her side in this manner until she dies.
When did the Female Orca take the Lead?
It makes sense for orca whales that have honed their survival instincts for decades to become pod leaders. After all, even though the younger whales might have more energy to burn, they still need to learn how to properly deal with everything from food shortages to unexpected weather changes. Therefore, putting an experienced whale in charge that has lived long enough to develop all of these essential skills is a good idea. This does not necessarily mean that any members of the pod consciously make this decision, though.
Scientists are still learning how and why orca whale pods work, so it is possible that this hierarchy developed as an adaptive measure throughout the evolution of the species. This would be consistent with the drastically different social structure that has evolved in humans during the past few centuries. As an example, it used to be common for children to be considered adults by their 13th birthday, and many of them were married or even ruling entire kingdoms by this age. We have learned as a species that this is not the best way to preserve our population, and we have also evolved to develop longer lifespans. This same learning curve and period of developmental adjustments has almost certainly occurred within the whale world, as well.
© Michael Wenger | Oceanwide Expeditions
Regardless of the leader of a pod, it is always fascinating to see these magnificent creatures of the sea while traveling through the Arctic or visiting locations such as Greenland. However, this newly announced information will give people something new to watch for while they are enjoying an Arctic expedition.