Self-maintenance
Like other corvids, Black-billed Magpies indulge in anting (applying ants onto their plumage) and sun-bathing (back facing the sun, head down, wings drooped and spread wide, tail fanned, back feathers fluffed up). They also belong to that group of birds that scratch their head with their foot over the wing.
Molt begins earlier in males than in females, and in second-year birds than in older ones. Primaries, secondaries, tertials and rectrices are replaced sequentially, so the bird can still fly during molting.
Read more about this topic: Black-billed Magpie