In much of the world, fully evolved dragon pokemon are fearsome beasts which extort vast tributes of gold and other priceless treasures from surrounding villages by threatening to pillage them; Noivern are no less terrifying, but the tribute they demand is paid in fruit. When these pokemon first flew out of their caves at night, local authorities were baffled by their ransom; while the taste of Kalos' fruits was certainly prized by many aristocrats and wild pokemon, any dragon hoard built on them would swiftly rot away.
Some lords obliged the Noivern, grateful that they wanted nothing more; a few, noting their painfully loud screeches, assumed they had misheard and provided them with items whose names sounded similar to fruit in the local languages. Some foolish nobles were so baffled that they sought to persuade the Noivern to take more traditional treasures, but they succeeded only in persuading the Noivern to take both gold and fruit for their troubles. In a few instances, a village attempted to hide fruit or switch to crops which did not interest the Noivern, while others had simply never grown it to begin with; these settlements learned that a sound dragon's wrath could be just as deadly as the traditional kind's.
The Noivern tribute never posed a financial burden on Kalos as a whole, but could be deadly to fruit growers, and when they sought to dodge tribute far more subjects became victims of Noivern's wrath. To rectify this, a wise king proclaimed vast festivals of tribute, at which the Noivern were satiated, their tributaries reimbursed and honored, and the rest of Kalos got to enjoy an entertaining ceremony. However, the decline of central authority in Kalos has renewed the Noivern's depredations, and not everyone can become a pokemon master to defend their crops.