Behavior of wild elephants in group
A new study of wild elephants in Africa, led by ecologist Karen McComb at Durham University, found that those older males who survived the most were likely to be dominant when they were young. They were also more likely to lead groups when they reached old age.
The study was published today in the journal Nature Ecology & Evolution.
“Leadership and status are important for elephants,” says McComb. “It is essential for hunting, for defending their territory, for attracting a mate, and for finding food. We wanted to know how older males became leaders, and what role this played in the lives of the younger elephants.”
McComb’s team tracked the movements of 45 male elephants in Botswana’s Chobe National Park between 2001 and 2015. These were the oldest elephants they could find in the park, with an average age of 40.9 years. The researchers studied their movements to find out which ones were likely to lead groups of younger elephants.
They discovered that elephants who survived the longest, and had the longest periods of good health, were most likely to lead when they were young. They also found that older males were more likely to lead when they were younger if they were part of a dominant, all-male group.
The researchers then used satellite tracking to follow the movements of one group of elephants, with an average age of 32.5 years, over the next five years. They found that the oldest male in the group, called ‘Bull No 1’, became the leader after his closest relative died.
Bull No 1 died in 2016, but his role as leader of the group was taken over by a younger male called ‘Bull No 2’, who was also one of the oldest elephants in the group.
When Bull No 2 died in 2017, his role as leader was taken over by another male, Bull No 3.
“We found that the oldest elephants were more likely to become leaders if they were part of an all-male group, and they survived longer than their younger counterparts,” says McComb. “The older males we studied were the oldest males in the park, so they were very experienced.”
The researchers believe that the role of older males in the group may help younger elephants to survive, by helping them find food and water.
“Younger males are likely to die before reaching old age, so the oldest elephants may provide a valuable service by finding food and water for them,” says McComb.
The findings also have implications for human-elephant conflict, because it shows that older males are the ones most likely to die in conflict.
“The role of old males in conflict is poorly understood, but we have found that these males are most likely to die,” says McComb. “In this study, the oldest males were the most likely to die.”
This is an important finding, because it helps to explain why male elephants are more likely to die in conflict than females.
“It’s very important to understand how the dynamics of conflict affect male elephants,” says McComb. “Understanding how they lead the group, and how they become leaders, will help us to better understand how conflict arises, and how we can reduce it.”
While the elephants in this study were not killed by people, elephants killed by people are a major threat to the species. According to the International Union for Conservation of Nature, elephants are threatened by poaching for ivory, habitat loss, disease, human-elephant conflict, and habitat fragmentation.
It was also important to study this because in the wild, females are the dominant individuals and so the importance of females has been overlooked in the management of male elephant populations.
‘Bulls’ have a greater social role in elephant society than females. They are usually the dominant males in groups, and have the greatest chance of mating with a female elephant. Bull elephants often use strong-willed, dominant behaviour to dominate and intimidate younger, weaker bulls.
This study showed that in the early stages of a bull’s life, he is still extremely dependent on the females, who often feed him and take care of him as a young calf.
Male elephants, who are usually smaller and weaker than females, will frequently chase females away from their calves. They may also engage in fighting with other bulls, as well as females.
“Male elephants are sometimes portrayed as being aggressive, aggressive towards other male elephants and even aggressive towards humans. Our research shows that male elephants are often not aggressive at all.
“Bulls have to be aggressive in order to protect themselves and their offspring from other males. If they were more passive and submissive, it would make it easier for the females to be dominant and exclude the bulls from the calf rearing, which is important for their own survival.”
Dr Stephanie Piercey, from the University of Cambridge, said: “Bulls may not be aggressive towards humans, but this is likely because the female elephants are too protective of their calves to allow them to be bullied by bulls. It is possible that male elephants have the potential to be aggressive towards humans in the wild, but this is rarely seen.”
The researchers also showed that a bull is less likely to engage in aggressive behaviour towards other males when he is close to a female, and that when they were separated from the females, he was much more likely to attack another male.
The team worked with more than 100 bulls in two African countries – Tanzania and Kenya. They used a variety of approaches to measure the male elephants’ behaviour, including camera traps and ‘passive’ observer monitoring.
Dr Andrea Crosta, from the University of York, said: “These techniques allow us to track the behaviour of elephants over long periods of time and at various locations. This is a crucial step in developing effective management strategies for both males and females.”
In the wild, female elephants are the dominant group members, with the males only coming to the fore when they are defending a territory or giving birth.
But the researchers found that female elephants also have a strong leadership role, and in the early stages of their lives, they can be just as dominant as the males.
“This is important because it shows that females can be equally important in the social structure of elephant societies. The female elephant, like many other mammals, plays a key role in reproduction and caring for the young. But female elephants are also extremely important in protecting and raising their young,” said Dr Piercey.
The team also found that male elephants tend to be very loyal to their females. They tend to fight less with other males and stick with their own group for longer.
“When they were not with the females, the males were much more likely to attack other males, and we found that they also showed more aggression towards the females when they were separated from them,” said Dr Piercey.
“This is very interesting because in the wild, female elephants will sometimes fight with each other and also with males. But in the areas where we worked, they didn’t fight with each other or with the males.”