Rumbling by adult females in the context of Coalition formation. During conflicts between females, especially between females from different families, or between a female and a young male, the matriarch or another large adult female often comes to the aid of a younger member of the family. During such Coalitions, the older female rapidly approaches the female in conflict and, as she reaches her side, they may display High-Fiving, Open-Mouth-to-Open-Mouth, reciprocal Trunk-to-Mouth, Tusk-Clicking. As they raise their heads high they and prepare for a joint attack on a young male or on another female(s) they Rumble in unison. We refer to calling in this context as Coalition-Rumbling. In Gorongosa, we observed this same behavior as family members coalesced to form a Coalition against us.
We do not have a large enough sample size of calls emitted in this context to know whether calling associated with this type of behavior is a separate Rumble sub-type, but the specific behavior of the elephants when calling, suggests an area for further research.
References: Poole 2011. (Full reference list)
This behavior occurs in the following context(s): Coalition Building