I have 7 birds (3 leghorns) and just today I noticed that the one leghorn has gone from a normally perfectly snow white head to one that looks dirty. In two spots it is a bit bald like a couple feathers have fallen out. The head also has these little black dirt like places on it, that look like little small black dirt dots on the end of the feathers. The bird is eating and behaving normally otherwise. Is this molting? The birds are less than a year old.