A: Your cardinal must have been the victim of an accident, unless he had a violent encounter with a bird of prey or with a cat. Fortunately the feathers will grow back. All the feathers of a bird are renewed at least once a year, usually after the breeding season and before the fall migration, at least in northern migrants, that is when the energy needs are less.
The feathers represent from 4 to 12% of the weight of the animal and require a lot of energy at the time of their replacement. Several species also have one or two other partial moults. This is the case of ptarmigan which moults three times a year. Usually the feathers fall symmetrically so as not to hinder the flight of the bird. However, during the summer moult, geese and ducks are nailed to the ground, or to the water, we should say, for a long time because they were unable to fly. As for your minor woodpecker, it is not impossible indeed that it settles there to nest as it sometimes happens.