The short answer is yes. While experts aren't exactly sure why this happens, they do believe it is rarely harmful. Most believe that it is a part of the natural molting process that for some reason in a few individuals goes a little wrong and they lose all their head feathers at once instead of the typical "few at a time" pattern. Because it occurs in late summer and early fall, weather is not a factor. In some cases, the feather loss can be caused by a lice or mite infestation. In both cases, feather growth is seen rather quickly and the birds seem to do just fine.