A good indication of the form of a male shama is the colour of the inside beak.  When a male shama is not in form, the colour will be a pale light brown/yellow.  It will darken when the bird is in form as can be seen in the bird below.  Ideally, the colour should gradually darken over a period of weeks as the bird form of the bird improves.  When a bird's form improves in this way, it is indicative that its care is correct.  This type of form tends to last for several months.  Sometimes, a bird that is not yet in full form may get excited by the presence of other male shamas or other event and suddenly seem to come into form, with its inner beak darkening in the space of several minutes.  This type of form tends not to last and the inner beak will revert to its light colour within a few hours of the event ending.