If you have a hen she will sometimes pluck the feathers of the young chicks. If she does you will need to remove the chicks from her area. Broken bones can occur also so be sure to notice if he has one leg drawn up, it could have been injured and you will need to take the bird to the veterinarian to get the bone set. Be sure to notice if he has had an injury that he doesn't go into shock. If he has party closed eyes, is passive, shallow or rapid breathing take him to the veterinarian immediately.
Parrots can have digestive problems that can lead to serious illness.
At any sign of a digestive problem consult your veterinarian as some of these illnesses can be spread to humans in the household. Be sure to take a sample of his feces when you take him to get treated. Watch for respiratory problems if he is sneezing a great deal and if mucus or fluid are present. Notice that his eyes are busy to see if he is feeling well. You might need to have a filter for the air in his area if he is having respiratory problems.