Is this mating behaviour by the two front left?
by yshish moderator, translator
It is an ecstatic display call. You'll see it often at the beginning of the breeding season when a pair meets and starts bonding. It strengthen the bond also when a partner returns on the nest after a long absence.
by gardenmaeve moderator
@Lennoxville - As yshish said- You'll see it explained in FAQ 5.1, https://talk.penguinwatch.org/#/boards/BPZ0000007/discussions/DPZ0000ade