Berries are not only a delicious treat and a way for savvy trainers to pick up a crucial boost in battle for their pokemon; in pre-unification Alola, they were a vital strategic resource. A well-timed Sitrus or Liechi Berry even today can change the outcome of a battle, and this was no less true when pokemon fought beside their trainers and their whole village for land, honor, and power. A proverb of the time said that pokemon without berries were like humans without helmets, and any successful Kahuna had to recognize the importance of supplying their army's pokemon with berries.

Trumbeak are frugivorous birds, so they were once reviled as pests. But one ambitious Kahuna, watching his best soldiers struggle to repel the quick-flying pokemon from his own military groves, wondered what would happen if he could turn the Trumbeak on his enemies. Wild Trumbeak often fly too high and erratically to be easily captured, especially in the absence of a flying pokemon of one's own – or one easily able to shoot them down. But Pikipek are the Alola region's most common birds, and given proper training from a young age, they can evolve into an elite corps of Trumbeak which could pluck a whole grove bare – or worse, seize a foe's berry in the midst of combat and use its boosts for itself.

The initial Trumbeak corps gave one Kahuna glory, allowing him to unify Melemele Island for the first time in its history. But Trumbeak are common birds, and it was not long before others across the region learned to do the same. Today, Alola is at peace, and the islands teem with Trumbeak; trainers are advised, just like successful kahunas before them, to mix up their strategies and hand their pokemon items which Trumbeak can not steal.