Elephants prefer to chat to elephants that they have known for a long time. This has been revealed in a study carried out at Walt Disney's Animal Kingdom where six elephants' rumbling communications were recorded along with intensive behavioural monitoring. The findings of the study, published in the journal of Animal Behaviour, show that elephants do not make rumbles at random.
They are twice as likely to make a rumble shortly after another animal vocalises, suggesting that elephants are replying to the first rumble. The herd of six elephants consisted of three pairs of elephants that had been brought together over time and formed their own social hierarchy.
Who was talking to whom did not depend on the elephant's place in the herd structure, but more on the number of years the animals had spent together before being integrated into the new herd. The elephants also rumbled at each other in a variety of circumstances – when they were close together, when they were far apart and also when they were being reunited.
Elephants that had been brought up together also chatted when approached by a dominant animal. Analysis of the sound wave characteristics of the rumbles was not so clear cut as the identification of the elephants replying to each other.
Rumbles could not be precisely defined into categories, but individual elephants could be identified from their calls. To some extent the mood of the elephant could also be determined. When elephants were in a tense social situation with a higher ranking elephant, they tended to produce rumbles in a lower tone with a less stable pitch.