SOS Encounter: Route 2, Route 3
Walk: Route 3 (49%), Route 2 (40%)
Surf: Route 3 (70%)
+ 1 more way
Its base catch rate is 255 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 Nest Ball, Safari Ball or Level Ball.
Evolution: Spearow → Fearow (Level 20).
Spearow in every game · Pokémon Sun, Moon, Ultra Sun & Ultra Moon interactive map (Alola)