While in predkour you should be able to have melee weapons equipped, and when you leap you should have the ability to melee slam and leap slam. Leap Slam uses R2 to charge, so use L2 to Melee Slam. Melee slam would have a lock on to FT and would deal more damage, but in turn only has normal melee AOE.
Also, @OldKingHamlet and @Courier, please fix the trees because when I use x to leap between branches, occasionally the Predator will just miss his jump and fall out of the tree.