These birds are primarily dark coloured. By the time they are 4 or 5 years old, they will develop a distinctive white head and tail feathers. The adults also have a large yellow beak.
Juveniles often have white mottling, especially under their wings.
When seen soaring, these birds hold their wings horizontally flat and at a ninety degree angle to their bodies.
Taken at the Birds of Prey Centre in Coaldale, Alberta, Canada.