royal-tern-during-physical-therapy-for-an-injured-wing-
Tri-State rehabilitator performing a “flap test” on a royal tern in an outdoor aviary. This test was primarily performed on birds with wing injuries and was also used as a method of physical therapy. By holding the bird and moving it up and down in the air as it would fly, the rehabilitator could evaluate the symmetry of the wings flapping, the flapping rate, and its lift power while simultaneously forcing the bird to exercise an injured wing. Sometimes the test was performed on a non-injured bird that had the ability to fly but simply wouldn’t on their own.