Elephants remember their human keepers after more than a decade

They say an elephant never forgets, and according to this new study, that's not far from the truth. Researchers led by Martin Kranzlin from the Wilhelma zoological-botanical garden in Stuttgart, Germany explored whether African savanna elephants (Loxodonta africana) can remember human keepers even after more than a decade of separation.

The results were startling: elephants demonstrated a significant ability to identify familiar individuals they hadn't interacted with for years.

The experiment took place at the Serengeti-Park Hodenhagen in Germany, involving two elephants — Bibi, a 36-year-old mother, and her 14.75-year-old daughter, Panya. These elephants had previously lived at Tierpark Berlin, where they had interacted with keepers for a number of years before being relocated. When the elephants were transferred to new facilities, they left behind the keepers with whom they had formed bonds.

Now, more than a decade later, researchers set out to discover whether these animals still remembered their former caregivers.

The study was structured using a two-choice object test, which allowed the elephants to choose between stimuli associated with familiar and unfamiliar individuals. These stimuli included sounds, smells, and images from their former keepers alongside similar stimuli from total strangers.

The testing took place over a series of 35 days. During this time, elephants were exposed to different types of sensory stimuli — auditory, olfactory, and visual. And these stimuli were from three categories of people: their current keepers, their former keepers, and unfamiliar individuals. This allowed the researchers to assess whether the elephants could distinguish between known and unknown humans using different sensory modalities.

An Elephant's Memory

For many wild animals, the ability to recognize potential threats in the form of another species (predators) is an important ability with major consequences. For animals who live in social groups, it is additionally important to recognize members of the same species and to be able to discriminate among individuals.

Gaining and storing this information is generally considered social knowledge, and for animals like elephants, social knowledge is essential. However, it's not clear to what extent this social ability also extends to other animals, like humans. We're not part of the same species, we're sometimes a threat, and sometimes an ally. So how do elephants view humans?

An important part of the equation is how elephants sense other animals. Elephants, especially African savanna elephants, have a keen sense of smell one of the most highly developed in the animal kingdom. So, this was a key testing area.

For the first test, their former caretakers were asked to wear a prepared white cotton T-shirt for 8 hours during the night, with no contact with other people or animals. They were asked to take a shower and not use deodorant or perfume.

"We are aware that the elephants would perhaps be familiar with the holistic odor of the keeper. However, it is very likely that the composition of the care products themselves as well as the routine of the test person may have changed over the last 13 years," the researchers say.

The team also carried out a visual test (with lifesize photos of the caretakers) and an audio test where recordings were played.

Testing the Elephant Mind

The elephants had not been in contact with their former caretakers for up to 13 years. Still, Bibi was sometimes quite fearless about the setups, whereas Panya was much more cautious. The keepers described Bibi as an elephant that may be dominant in her interactions.

The elephants were in an enclosure but they could reach their trunk towards the T-shirt or the photo. The trunk reach duration and time of interest were measured.

The elephants were much more interested in the scents belonging to their former keepers than other, unfamiliar scents. They seemed to recognize the scent and show interest in it. The same happened with the photos, even though elephants' vision is far less keen than their sense of smell.

This suggests that elephants can use both scents and visual information (albeit to a lesser extent) to recognize humans after periods of separation. But with hearing, it went differently.

A similar study was carried out with voice recordings of the keepers saying simple phrases. Interestingly, the elephants did not show a significant preference for the voices of their former keepers over unfamiliar ones.

This result was surprising given that elephants are known to use vocalizations for long-distance communication and can recognize conspecifics (other elephants) by their calls. The researchers hypothesized that the elephants may have paid more attention to the general sound rather than specific voice characteristics, or that auditory recognition of humans might be less developed than olfactory memory. However, it's not yet clear whether this is the case.

Evidence of Memory

The results of this study provide the first scientific evidence that African savanna elephants can store and recall information about specific humans for over a decade. This finding builds on existing knowledge about elephants’ cognitive abilities, particularly their social memory.

Elephants in zoos often develop strong bonds with their keepers. And studies have shown that these relationships can reduce stress levels and enhance animal welfare. The discovery that elephants can recall keepers they haven't seen for years suggests that these bonds are even deeper than previously thought.

Recognizing that elephants can form long-lasting memories of their keepers can lead to new approaches to managing these relationships. This is especially important when animals are transferred between facilities. For example, zoos may consider allowing keepers to visit elephants they once cared for, especially during stressful transitions like relocations.

Understanding that elephants retain these memories could help us to improve their psychological well-being. Moreover, knowing that elephants have this capacity could also influence the way zookeepers and other human handlers interact with them, emphasizing the importance of consistent, positive interactions to foster long-term bonds.

More Work to Be Done

But this can make a difference outside of zoos as well. Notably it may help in areas where human-elephant conflict is an issue, such as parts of Africa and Asia. This memory capability could play a role in mitigating negative interactions between people and elephants. In the wild, elephants distinguish between threatening and non-threatening human groups.

In fact, they even remember specific human ethnicities based on past experiences. This new research suggests that elephants might also retain long-term memories of individual humans. And this could influence their behavior during human-wildlife encounters.

However, this is still a small-scale study and carried out in an environment where not everything was controlled. Researchers caution that additional studies should be undertaken before definite conclusions can be drawn.

There were many influencing factors that could have affected the animals' behavior, so the findings of this experiment are to be interpreted with caution," the team concludes.

The study was published in the journal Zoo Biology.