As many people know, African elephants (Loxodonta africana) live in complex matrilineal societies, with closely-knit family groups led by a matriarch who is typically the oldest and largest female in the family. In order to appreciate the importance of these matriarchs, it may help to first consider a traditional Japanese folktale:
Once there was an arrogant young village lord who, deciding that old people were useless, banished them to the mountains to die. Although the villagers were distressed, they obeyed rather than face severe punishment. One young farmer couldn’t bear to follow this cruel decree, though, and hid his aged mother away in a safe and secret room.
Several years later, an invader arrived, announcing that he’d spare the village only if three tasks could be performed. First, he must be presented with a box containing one thousand ropes of ash. Next, a silk thread must be drawn through a small hole that bent seven times along the length of a log. Finally, he must be given a drum that sounded without being beaten.
In each case, the village lord offered rewards, cajoled and threatened the townspeople, but nobody knew what to do; all were in despair. The tasks all seemed impossible. Each time, though, the farmer asked his mother and she knew the answer: soak ordinary rope in salt water before burning it; tie the silk thread to an ant at one end of the hole and place sugar at the other; put a bumblebee in a drum and it will buzz as it tries to escape. The village was spared.
Ultimately, the lord finds out that they have all been saved by the wise old mother, and from that time on elders in the village are revered.
Shifting scenes now from the mountains of long-ago Japan to the plains of today’s Africa, it turns out that older matriarch elephants are much like the heroic old Japanese mother – they are the ones with the answers, the ones that can save their fellow elephants from outside threats with the wisdom they have accumulated through experience.
As we know from the decades of observation and research performed by Cynthia Moss and her colleagues in Kenya and Tanzania, matriarch elephants act as group leaders, holding together their families and providing behavioral guidance during times of crisis. Many observers believe that the oldest matriarchs – those with the most experience and greatest ecological knowledge – make the best decisions, but until recently it has proved to be difficult to quantify the relevant skills in a manner conducive to experimental testing.
In a March 2011 paper published online in the Proceedings of the Royal Society B, however, a team of scientists led by Karen McComb of the University of Sussex reported on a clever set of experiments that tested whether older Amboseli National Park matriarchs were better than their younger counterparts at assessing the perceived threat posed by various lion roar recordings.
While African elephants are able to fend off most natural predators, they have to watch out for lions, who occasionally prey upon younger calves. Also, even though lionesses perform the, ahem, lion’s share of the hunting for the pride, male lions actually pose a greater threat to elephants. Male lions, despite their generally well-deserved reputation for laziness, are, on average, half again as large as females and much stronger, giving them a better chance of overpowering a vulnerable young elephant.
Accordingly, the researchers assembled lion “playbacks” in four separate categories – single female roars, single male roars, three female group roars and three male group roars – which they then played to 39 elephant family groups over a period of slightly more than two years. Because of the extensive demographic information compiled by the Amboseli Elephant Research Project, they knew the age of the matriarch in each of the 39 families.
After playing the different roars, the researchers analyzed video of the elephants’ responses, focusing particularly on the behavior of the matriarchs. They documented specific defensive reactions, including prolonged listening to the roars, whether the family bunched around the matriarch after hearing the roars, the speed and intensity of any bunching behavior, and whether the matriarch changed her direction and moved toward the source of the playback.
Here are two brief videos, one showing an elephant family reacting to lion roars and the other narratively describing the reactions as reflected in still images:
After recording all of the responses, the research team performed statistical analyses and sorted their results by matriarch age. They found that, while matriarch age did not have an impact on how the elephants reacted to varying number of lions (all elephant families consistently ratcheted up the intensity of their response when the number of lions roaring went from one to three), it did have a strong impact on the elephants’ response to the more serious threat presented by male lion roars, with male roars leading to more prolonged listening and intensive defensive bunching in families led by older matriarchs.
As the researchers put it:
Our work provides the first direct experimental evidence that older matriarchs are in fact able to make better decisions when faced with ecological challenges — in this case, the presence of dangerous predators. It thus bridges an important gap between theoretical predictions about how knowledge might be expected to affect leadership and empirical studies, which to date have been largely confined to observational accounts.
Based on these findings, I’m quite confident that the older matriarchs will do quite well on their next set of tasks involving burning ropes, crooked logs and drums. Now, if only that was enough to keep humans from invading their villages….
The Japanese folktale can be found, among other places, in The Wise Old Woman/retold by Yoshiko Uchida; illustrated by Martin Springett. ISBN: 0689505825.
McComb, K., Shannon, G., Durant, S., Sayialel, K., Slotow, R., Poole, J., & Moss, C. (2011). Leadership in elephants: the adaptive value of age Proceedings of the Royal Society B: Biological Sciences, 278 (1722), 3270-3276 DOI: 10.1098/rspb.2011.0168.