Reaching of the trunk to touch, or near touch the temporal gland of another typically in a Social Play or Affiliative context. This behavior is often observed during Sparring and following meeting/greeting of individuals. Elephants are very tactile animals with a tremendously perceptive sense of smell. More research is required to fully understand why elephants touch different parts of the faces of other elephants.
References: Poole 1982: 37 illustration; Rasmussen & Wittemyer 2002; Poole & Granli 2003; Poole & Granli 2004, Poole & Granli 2011 [Test-Temporal-Glands]; O’Connell-Rodwell et al 2011 [Trunk to head & Trunk to temporal glands]. (Full reference list)
This behavior occurs in the following context(s): Affiliative, Social Play