Why Matriarchs Matter in Elephant Society
Whenever I’m asked about elephants and the work I do, I invariably end up talking about matriarchs, as they form both the core of elephant society and the core of this study. Why are matriarchs so important to that society?
A matriarch is a leader of an elephant family, and is usually the oldest female in that family. My particular interest within the Amboseli Elephant Research Project (AERP) focuses on what is happening to families who lost their matriarchs in the devastating 2008/2009 drought.
Elephant families revolve around females. Males leave at puberty and become socially independent, but females remain within their families for their whole lives. They rear their calves alongside their mothers, grandmothers, sisters and aunts. Elephant families are extremely fluid in their association patterns meaning that not all members are together all of the time. This wonderful flexibility and fluidity in elephant society, which we call “fission-fusion”, is one of the things that I find so fascinating about elephants.
When food is scarce, elephants will spend more time with just one or two other family members and their calves, rather than with the whole family together, although they remain co-ordinated, to a degree, by using vocalisations.
When they’re together, family members take their cues from the matriarch – as the leader, her decisions influence when the family eats and where, when they spend time with other elephants, and when to leave the large groups of animals that form around feeding and drinking sites.
If family members want to do something different from the matriarch, they will have to leave the family for a while and catch up later. Since old females have a lot of experience in getting the most from the environment, it usually profits the rest of the members to follow her lead. And they usually do. Good matriarchs need to balance the needs of family members so that they can stay together, and the amount of time that a family spends together is affected by the degree of conflict in individual needs. For example, the mothers of young calves need to drink more frequently in order to maintain their milk production.
It’s easy to see there are both costs and benefits to staying within a family; the costs include having to “put up” with what everyone else wants to do, when their interests might conflict with your own.
Of course there are benefits too - not only in gaining the experience from a matriarch who remembers when to visit a particular area to feed, but also her experience in dealing with special or threatening events.
Females support their daughters the first time they come into oestrus and are ready to be mated, when they give birth, and in caring for young calves (which have a remarkable propensity to get stuck in mud, or lost in bushes).
Matriarchs lead their families away from dangers such as predators, and older matriarchs are better at responding appropriately to threats, as shown by a series of elegant “playback” experiments by Amboseli collaborators Karen McComb and Graeme Shannon, these recently attracted a lot of media attention.
Matriarchs thus shape the daily lives of family members, and by doing so affect their general health and body condition, and therefore influence their survival and their reproductive success.
Analyses of the long-term data gathered by the AERP since 1972 have shown that when families have older matriarchs, every female in that family reproduces at a faster rate. This makes families larger, and even more successful, as pre-reproductive females in the family provide calf-sitting care known as “allomothering” which increases calf survival. This allows mothers to concentrate more on foraging, and thereby boosts their milk production.
So families flourish with old, experienced leaders at the helm, and their loss is severely felt by family members. The death of a matriarch is inevitably followed by a period of confusion amongst the family; as the matriarch is the oldest member of the family, the surviving members will have known her for their entire lives. Losing the “rallying point” inevitably alters their daily activity patterns, and sometimes their ranging patterns (i.e. the areas they use).
It takes time for a new leader to emerge, and if the eldest females are particularly close in age, they may split and form two (or more) new families. Part of my study examines this process, and whether families that lost multiple females over the drought period suffer more from these losses than other families.
In previous blogs, I’ve written about learning to identify the Amboseli elephant families and the individuals in those families. By spending time watching elephants, you learn their physical “marks” or characteristics that allow you identify individuals, but you also learn the particular character traits of the individuals. Some females are strong confident leaders, whilst others are more nervous and prone to be vigilant. Some are very maternal and patient, for example waiting for everyone to be ready before moving off from a resting spot, whilst others are much less so.
The matriarchs leading my study families have their own characters and personality traits, and that influences the overall family characteristics: Alison, the leader of the AAs is not a very strong leader, and often the family is split three ways with each of the oldest females – Alison, Agatha and Amelia – leading their daughters and calves. The AAs are quite a large family, with 23 members, which may partly explain why they’re not very cohesive. Even when together, they often travel in “sub-groups” so that they’re in the same area, but not travelling in one cohesive group.
In comparison, the JAs are a small family with just 10 members, and their matriarch Jolene keeps everyone together much of the time. Olympia is the matriarch of the OAs and, I have to confess, already a favourite of mine. Born in 1980, she’s just a year older than I am, for a start, and she has beautiful tusks – they curve gracefully upwards and are very symmetrical. The OAs are also interesting because when their matriarch Orlanda died during the 2009 drought, an older female Orabel split and formed her own family. At 43, Orabel is significantly older than Olympia, and the dynamic between the two females and their respective families is interesting. Olympia is Orlanda’s daughter, and I wonder whether being a matriarch’s daughter might somehow help Olympia make up for her relative lack of age and experience. Or she may choose to spend time Orabel, and gain experience that way. That’s just another question where we have to wait and see what happens next…
For more information on the work of the Amboseli Trust for Elephants in Kenya, visit http://elephanttrust.org
For more pictures of the families, click here.
For more information on the International Fund for Animal Welfare effort to save animals including elephants around the world, visit http://www.ifaw.org