Think for a moment about feathers. They provide birds with protection from the environment, enable them to fly (well, most of them at least), and identify them to one another – and to us as well. So when a bird molts, as it must do at least once each year to replace worn or damaged feathers, problems in all these above-mentioned areas occur.
In the case of the molting bird in this image, uploaded to the Wingscapes Photo Gallery by Glenna from Mississauga, Ontario, many of the feathers crucial to its identification are not present. Any guesses as to what it might be?