Bull elephants use deep rumbles to say ‘let’s go’

In the coolness of evening, bull elephants gather at a waterhole to drink. After a while, a senior male signals the group to move on with a deep rumble. One by one, the others respond, their infrasonic calls creating a harmonious chorus that echoes across the savanna, indicating it’s time to leave.

For the first time, scientists from Stanford University and other institutions have documented male elephants using these “let’s go” rumbles to coordinate group departures from the Mushara waterhole in Etosha National Park, Namibia. 

Sophisticated vocal coordination 

This vocalization behavior, initiated by the most socially integrated and dominant males, was previously thought to be exclusive to female elephants in family groups.

“We were astonished to find that male elephants, typically considered to have loose social ties, engage in such sophisticated vocal coordination to trigger action,” said study lead author Caitlin O’Connell-Rodwell, a research associate at Stanford University’s Center for Conservation Biology. 

“These calls show us that there’s much more going on within their vocal communication than has previously been known.”

Recording the elephant rumbles 

O’Connell-Rodwell first recorded the male “let’s go” rumble in 2004 during nighttime fieldwork to understand how elephant vocalizations travel through the ground. 

“I was so excited when I managed to record it,” she recalled. “It was thrilling to realize that these males were using complex vocal coordination like the females were.”

From 2005 to 2017, the team collected data at the Mushara waterhole, mainly during the dry seasons. They used high-tech recording equipment, including buried microphones and night-vision video cameras, to capture the infrasonic vocalizations and behaviors of male elephants. 

The researchers analyzed the vocalizations for acoustic properties and patterns, using social network analysis to understand relationships and hierarchy among the males, noting which elephants initiated the rumbles, how others responded, and the sequence of events leading to the coordinated departures.

“Let’s go” rumbles are learned behaviors 

The “let’s go” rumbles observed in male elephants are strikingly similar to those recorded in female elephants. O’Connell-Rodwell and her team hypothesize that male elephants likely learn this behavior when they are young. 

“They grew up in a family where all the female leaders were engaging in this ritual,” she said. “We think that as they mature and form their own groups, they adapt and use these learned behaviors to coordinate with other males.”

Both male and female elephants follow a turn-taking pattern in their rumbles, creating a harmonious vocal coordination akin to a barbershop quartet. “It’s very synchronized and ritualized. When one goes high, the other goes low, and they have this vocal space where they’re coordinating,” she explained.

The language of elephants 

The study builds on previous research that used AI to reveal that wild elephants have unique names for each other, indicating the use of nouns in their communication. 

“In our paper, we show that elephants are using verbs in the form of this ‘let’s go’ rumble. If they are using noun-verb combinations together, that is syntax. That is language,” said O’Connell-Rodwell.

Mentoring roles of dominant males 

The study also highlights the mentoring roles of some dominant male elephants within their social groups, helping to maintain cohesion and stability. 

“These individuals take on mentoring roles,” noted O’Connell-Rodwell. “They care about these young whippersnappers who are very needy and always wanting to be in physical contact. The older males are willing to take them under their wing, to guide them, share resources with them, and partake in their emotional ups and downs.”

Social lives of male elephants 

In countries that allow hunting, care should be taken to avoid hunting older socially connected male elephants, as their removal could disrupt social cohesion and mentoring structures within elephant populations. 

The research also suggests that strong social bonds and interactions are essential for the well-being of captive and semi-captive male elephants, highlighting the need for environments that support these social structures.

“Our findings not only underscore the complexity and richness of the social lives of male elephants, but also advance our understanding of how they use vocalizations in ritual and coordination and, really, move us closer to the idea of elephant language,” O’Connell-Rodwell concluded.

The study is published in the journal PeerJ.

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates.

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–