Table 1B.

Previously published details of postulated intraspecific contagious yawning episodes (19).

Initiating elephant	Responding elephant	Description
Contagious yawning in a standing elephant
Mashudu	Nandi	One sub-adult male (Mashudu) and one adult female (Nandi). Nandi had been standing for over 5 min. Mashudu, initially lying down, starts standing and then yawns while starting to stand. Nandi then starts yawning 18 s later with no overlap in yawning times. Occurred in association with the final recumbency for Mashudu.
Contagious yawning in arousing elephants
Mashudu	Keisha	One sub-adult male (Mashudu) and one adult female (Keisha). Both elephants initially lying down. Mashudu stands first, and then Keisha starts standing. Mashudu starts yawning, and Keisha starts yawning 2 s later with a 2 s overlap in yawning times. Occurred on final recumbency for both elephants.
Nandi	Thandi	Two adult females (Nandi and Thandi). Both elephants initially lying down, then both start standing. Nandi starts yawning, and Thandi then starts yawning 5 s later, with an 8 s overlap. Occurred on the final recumbency for both elephants.
Nandi	Shungu	One adult female (Nandi) and one sub-adult male (Shungu). Both elephants initially lying down, then both start standing. Nandi starts yawning, and Shungu then starts yawning 6 s later with a 3 s overlap. Occurred on the final recumbency for both elephants.
Keisha	Thato	One adult female (Keisha) and one sub-adult female (Thato). Both elephants initially lying down, then both start standing. Keisha starts yawning, and then Thato starts yawning 16 s later, with no overlap in yawning times. Occurred on the final recumbency for both elephants.
Mashudu	Clyde	One sub-adult male (Mashudu) and one adult male (Clyde). Both elephants initially lying down, then both start standing. Mashudu yawns, and then Clyde yawns. Information on delay between the starting of yawning and overlap times could not be discerned. Occurred on the final recumbency for both elephants.