Updated: Feb 12, 2021
Today is my sister’s birthday and, inspired by her fearsome love and protectiveness, this blog is dedicated to her. In it, I explore the incredible bonds that tie sisters together throughout the animal kingdom, and in doing so reveal some of the most fascinating behaviour on our planet. The first of these examples is elephants, whose familial herds are led by ancient matriarchs who guides her daughters, sisters, and their daughters, using their wisdom and experience. The next are lionesses, whose prides consist of related females, who hunt, feed and protect together. Finally, the hyenas, whose dominant female clan members possess unique biological qualities that equate to some of the most extraordinary examples of evolution on our planet.
A matriarch guides her herd. Photo credit: Hannah Gormley
Botswana is home to the majority of the world’s last remaining enormous elephant herds. At the head of each is a matriarch, the largest and oldest female, and leader of her daughters, sisters and their offspring. Through generations of matriarchs before her, she has learned the best migratory routes, the sites of sweet grass and year-round water sources, and the dangers posed by predators and poachers. She leads them through times of plenty and times of drought, and passes on her invaluable knowledge to her sisters and descendants. One example is that of childcare. Elephants are demanding babies who possess little evolutionary instinct and are instead taught nearly everything they know by their herd-mates. Under the guidance of the matriarch, sisters of the new mothers work together to raise the new-born and assist in its taxing childcare. Once the matriarch passes, it is typically her eldest daughter who takes over. As poaching presents an ever-increasing threat to elephants we look to areas of Africa where these families have been ruptured by the targeting of large matriarchs. One study, from Tanzania, shows that poaching led to younger matriarchs, who led herds with weaker social bonds, lower relatedness, fewer calves and indications of chronic stress1. This powerful example reminds us of the importance of sisterhood and the urgent need to conserve elephants across Africa.
The sisterhood. Photo credit: Hannah Gormley
No one can be sure why lions evolved to live in prides. This transition happened relatively recently in their evolutionary history, before which they were solitary predators like leopards. The presumption is that it was a tactic to improve hunting success. You can imagine why, as if you’ve ever spent time with lions you’ll know that they are incredibly lazy, spending up to 20-hours a day sleeping. Working together also means that younger and injured pride members have a better chance of survival. However, the prides hold another valuable role for its members. That of protection. Lion prides can be considered ‘matriarchal’, since it is the related females who stick together and the related males that spread to take over new prides. Roaming male lions who come across a pride will make it a priority to kill all of the existing cubs to encourage the females to go into oestrus. This means that they can impregnate the females, so that they will be raising his heirs instead. The females, on the other hand, are fiercely protective of their cubs and will go to great lengths to avoid these males. In this respect, prides have three benefits. The first, safety in numbers. The second, a greater proportion of females are interested in fighting off the intruding males for the better of their sisters. The final, the pride can designate a ‘babysitter’ to guard their cubs while the others hunt. While the creation of prides may have made lions lazier, it has clearly has had no impact on their loyalties to their sisters.
A hyena babysits her's and her sister's curious pups. Photo credit: Hannah Gormley
Last but not least are hyenas. Spotted hyenas, to be accurate. While the Lion King has ruined their reputation, hyenas are some of the most incredible, intelligent and absolutely peculiar animals on our already weird and wonderful planet. Why? You can imagine the first scientific explorer’s curiosity when they arrived in Africa and found not a single female hyena. There were two equally outrageous possibilities for this conservative, sexist and strictly religious era: 1) male hyenas mate and give birth or 2) the females were hermaphroditic. Well, they weren’t far off with either. Female hyenas have evolved ‘pseudo-penises’ and enlarged growths that surround it that resemble testicles. And yes, through this ‘pseudo-penis’ the females typically squeeze out not just one, but twins. According to the fabulous author Lucy Cooke, this “eye-watering feat is like squeezing a cantaloupe out of a hosepipe, and one in 10 first-time hyena mothers die in the process. The fate of their cubs is even more precarious, since the umbilical cord is too short to navigate a birth canal that’s not only twice the length of a similar-sized mammal’s but includes a cheeky hairpin turn halfway down. Up to 60 percent of cubs suffocate on their way out”. Not only this, but female hyenas are also larger, fiercer and much more dominant than males, who rank near the bottom of their hierarchies. Like lionesses, these unique traits most likely evolved to ward off male dominance and danger. And, also like lionesses, hyenas live in clans formed of related females who scavenge and hunt together, and babysit and protect each other’s young. So, next time you underestimate a hyena, please remind yourself of the extraordinary lengths their mothers went through for them to be here and hold respect for their ultimate sisterhoods.
Popular science so often misguides its audience into believing that it is the males who are the providers and the protectors of every herd, pack or pride in the animal kingdom. I hope this blog has shown you how wrong that is. So, all I can say to round up is, thank goodness for sisters. Especially for me, as mine has the wisdom of a matriarch, the loyalty of a lioness, and shares none of the qualities of a hyena, except its sharp bite when provoked! Happy Birthday, Phoebs. How lucky I am!
Blog written by Hannah Gormley.
1: https://pubmed.ncbi.nlm.nih.gov/18759771/. Long-term impacts of poaching on relatedness, stress physiology, and reproductive output of adult female African elephants. K S Gobush; B M Mutayoba; S K Wasser.