"...and they began to practise such jumps in case they got in a similar situation." There's so much to wonder about in that statement. Couldn't they just not jump? Would they remember to tie the vines first? Did the women also have to practice? I can't go on, it's exhausting.
The Bunlap people perform an ancient ritual called Gkol, in which men tie vines to their ankles and jump headfirst from platforms jutting out from a tower. The jumper's fall is broken by the vines, the other end of which is tied to the tower. A sloping surface of softened earth at the base of the tower provides some protection from injury in case of a broken vine, a vine of incorrect length, or a poor jump. Gkol inspired the modern sport of bungee jumping, though the vines used are far less elastic than bungee cords, and the Gkol jumper does not bounce up at the end of the fall. The Gkol legend says that in the village Bunlap a man called Tamalie had a quarrel with his wife and she ran away and climbed a banyan tree, (which some recall as line in an old and admired song) where she wrapped her ankles with liana vines. When Tamalie came up to her, the woman jumped from the tree and so did her husband not knowing what had his wife done. He died but the woman survived. The men of Bunlap were very impressed by this performance and they began to practise such jumps in case they got in a similar situation. This practice transformed into a ritual for rich yam harvest and also for proving manhood.