Many of the adult Red-tailed Hawks that I saw and photographed in southwestern Montana on my last trip had worn feathers and were molting. Bird feathers are made from keratin, the same substance as our fingernails and even though the feathers are durable they do become worn and need to be replaced. The adult Red-tailed in my image shows worn primaries or flight feathers and it looks a little ragged. As with most birds this Red-tailed will go through a regular and predictable molt and will look sleek when the molt is done.
I think if I wore the same clothes every day for 365 days a year I’d look a bit ragged too.