A Rumbling, greeting exchange between members of an elephant family in which one (usually older and female) approaches another (usually younger, in parallel and from behind). Typically, the approaching elephant emits a soft, tonal Rumble of medium duration (2.5-4 seconds) to which the elephant being approached, responds by Head-Raising, Ear-Lifting and sometimes Backing-Towards the approaching elephant and emitting a responding, more noisy Rumble of medium duration and moderate intensity (although these are highly variable). Often both individuals Head-Raise and Ear-Lift and the two may Social-Rub against one another, touch one another or greet Trunk-to-Mouth. Both are likely to secrete Temporin. This interchange is a relatively frequent event in an elephant family and we refer to it as Little-Greeting-Rumbles. Examination of spectrograms indicate that in almost every case both the approaching and approached elephant call (although the softer call of the former may be drowned out by the more powerful call of the latter) and that their Rumbles overlap. In some cases nearby elephants may also join in. Elephants may also call in this manner when one approaches another face to face, although this pattern is less common.
Little-Greeting-Rumbles may occur between any member of an elephant family, including between two males, but they are most commonly heard between females. Little-Greetings occur more often between mother-daughter, sister-sister, grandmother-granddaughter pairs than expected by chance, and less often between aunt-niece, great-grandmother-great-granddaughter or pairs who were second cousins. Yet, some exchanges aunt-niece pairs show a high frequency of Little-Greeting-Rumble exchanges. In each case these are pairs in which the niece was an infant prior to the aunt having her first calf, and the aunt was the most likely candidate in the family for taking the role of allomother. Calves and their caretakers (often sisters and aunts) emit Coo-Rumble and As-Touched-Rumble exchanges under rather similar circumstances to Little-Greeting-Rumble exchanges and we believe that the Coo-Rumble and As-Touched-Rumble probably develops into a Little-Greeting-Rumble relationship.
We venture to propose that the relationships established through early vocal and tactile care-giving by mothers, sisters and other allomothers form the basis of close bonds observed as adults which are then strengthened and reinforced through the customary Little-Greetings between closely bonded pairs. The care-takers who looked after the Tsavo orphans were able to elicit the same type of answer Rumbles from the orphaned calves by individually calling out their names. Members of an elephant family appear to use this common vocal exchange as a way of saying something like 'hello, its good to be near you again' or, perhaps, 'you are important to me'.
References: Poole 2011. (Full reference list)
This behavior occurs in the following context(s): Affiliative