That would be its huge, secondary wing feathers, which along with the tail are used to woo females. The wings are full of ...

Thin and long tailed, with outer tail feathers almost entirely white (tail from below looks white). The bill is thin and pale gray. Breeding male: blue-gray above, including most of head and back.

A wildlife rehabilitator caring for the injured raptor said it could take two or more years for the feathers to return and give flight.