I hatched out 6 Marans chicks 5 weeks ago. One of the apparent rooster chicks is quivering. He puts up his rooster tail like a peacock and quivers when he does this. His legs also quiver when he walks. He has extra large feet too and kind of takes high, careful steps as his legs slightly quiver the whole time. He appears healthy otherwise. I noticed this about a week ago and the quivering continues. None of the other 5 have any symptoms. I have read about Mareks, not sure what to think, as he is definitely not paralyzed. Any ideas?