Where to find Trumbeak in Sun, Moon, Ultra Sun & Ultra Moon

SOS Encounter: Lush Jungle (15%), Route 11, Route 5 + 3 more
Walk: Route 8 (30%), Poni Grove (30%), Poni Plains (30%) + 2 more
Unknown: Route 5

Trumbeak also appears in

How to get Trumbeak in Sun, Moon, Ultra Sun & Ultra Moon

Its base catch rate is 120 out of 255 (higher is easier); the catch rate calculator works out your odds with each ball. For the look, the best colour match is Timer Ball or Luxury Ball.

Evolution: Pikipek → Trumbeak (Level 14) → Toucannon (Level 28).

Trumbeak in every game · Pokémon Sun, Moon, Ultra Sun & Ultra Moon interactive map (Alola)