Will vagrancy rates in the movement of migratory bird species increase with human induced environmental changes?

Migratory bird species trade off the hazards of migration for favourable environmental conditions at their “breeding” and “wintering grounds”. The extent of the migration ranges from short hops for altitudinal migrants to 15,000+ kilometre epics for trans-equatorial migrants. While some of the long distance migrants can fly direct from start of finish, others need to break their journey to rest and refuel.