There are 19 different species of owl in the North American region and each of them have different migratory patterns/habits. The Snowy Owl for instance tends to breed around the polar seas and migrates to the south when the weather starts to get a little colder. This species of owl has been described as being somewhat nomadic because of the fact that its migratory patterns are so sporadic and unpredictable.
Southwestern owls on the other hand have very predictable migratory patterns, sticking within its own range for the most part. Western owls are highly migratory creatures, though not much is known about their own patterns.