The swan may be picking at the end of a feather shaft that has not come out. The blood may even be from a blood feather. You probably need to get her to a veterinarian who can look at the wing closer. If it is piece of feather stuck, this would be similar to a hang nail or ingrown toenail. Not only bothersome, but possibly very painful for the swan. The veterinarian may be able to remove it by using a surgical instrument which would be somewhat similar to a pair of pliers. Surgery, might be indicated for something more serious.

If this area has not healed, there could be an internal infection. The veterinarian might need to conduct a biopsy of the area to insure that it is not cancerous and possibly prescribe an antibiotic that will promote healing in the event of an infection. The last thing you want to do is neglect this problem and it becomes septic for the bird, thus killing it. The Regal Swan