Behavior/Health Concerns: Biting and aggression seems to be common with males and excessive shyness more common with females. African greys are susceptible to feather picking, calcium, vitamin-A and vitamin-D deficiencies, respiratory infections, psittacosis and psittacine beak and feather disease (PBFD). African greys are sensitive to stress. These pet birds are capable of getting through the typical stressful moments that any family will encounter, but they will not thrive if kept in a home with extended periods of anxiety and stress.